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  • richardmitnick 11:42 am on July 13, 2017 Permalink | Reply
    Tags: , , , , Has America Really Lost It’s 'Lead in Space?', Many Worlds   

    From Many Worlds: “Has America Really Lost It’s ‘Lead in Space?’ “ 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-07-13
    Marc Kaufman

    1
    Vice President Mike Pence addresses NASA employees, Thursday, July 6, 2017, at the Vehicle Assembly Building at NASA’s Kennedy Space Center (KSC) in Cape Canaveral, Florida. The Vice President spoke following a tour that highlighted the public-private partnerships at KSC, as both NASA and commercial companies prepare to launch American astronauts in the years ahead. Pence spoke at length about human space exploration, but very little about NASA space science. (NASA/Aubrey Gemignani).

    I was moved to weigh in after reading Vice President Mike Pence’s comments last week down at the Kennedy Space Center — a speech that seemed to minimize NASA’s performance in recent years (decades?) and to propose a return to a kind of Manifest Destiny way of thinking in space.

    The speech did not appear to bode well for space science, which has dominated NASA news with many years of exploration into the history and working of the cosmos and solar system, the still little-understood domain of exoplanets, the search for life beyond Earth.

    Instead, the speech was very much about human space exploration, with an emphasis on “boots on the ground,” national security, and setting up colonies.

    “We will beat back any disadvantage that our lack of attention has placed and America will once again lead in space,” Pence said.

    “We will return our nation to the moon, we will go to Mars, and we will still go further to places that our children’s children can only imagine. We will maintain a constant presence in low-Earth orbit, and we’ll develop policies that will carry human space exploration across our solar system and ultimately into the vast expanses. As the president has said, ‘Space is,’ in his words, ‘the next great American frontier.’ And like the pioneers that came before us, we will settle that frontier with American leadership, American courage and American ingenuity.” (Transcript here.)

    That a new president will have a different kind of vision for NASA than his predecessors is hardly surprising. NASA may play little or no role in a presidential election, but the agency is a kind of treasure trove of high profile possibilities for any incoming administration.

    That the Trump administration wants to emphasize human space exploration is also no surprise. Other than flying up and back to construct and use the International Space Station, and then out to the Hubble Space Telescope for repairs, American astronauts have not been in space since the last Apollo mission in 1972. It should be said, however, that no other nation has sent astronauts beyond low Earth orbit, either, since then.

    Where I found the speech off-base was to talk down the many extraordinary discoveries in recent decades about our planet, the solar system, the galaxy and beyond made during NASA missions and made possible by cutting-edge NASA technology and innovations.

    In fact, many scientists, members of Congress and NASA followers would enthusiastically agree that the last few decades have been an absolute Golden Age in space discovery — all of it done without humans in space (except for those Hubble repairs.)

    To argue for a more muscular human space program does not have to come with a diminishing of the enormous space science advances of these more recent years; missions and discoveries that brought to Americans and the world spectacular images and understandings of Mars, of Jupiter and Saturn and their potentially habitable moons, of Pluto, of hot Jupiters, super-Earths and exoplanet habitable zones, and of deep, deep space and time made more comprehensible because of NASA grand observatories.

    To say that the United States has given up its “lead in space,” it seems to me, requires a worrisome dismissal of all this and much more.

    2
    Selfie of Curiosity rover on sedimentary rock deposited by water in Gale Crater on Mars. (NASA) [Interesting, where is an arm carrying the camera that took the selfie?]

    Let’s start on Mars. For the past 20 years, NASA has had one or more rovers exploring the planet. In all, the agency has successfully landed seven vehicles on the planet — which is the sum total of human machinery that has ever arrived in operational shape on the surface (unless you count the Soviet Mars 3 capsule which landed in 1971 and sent back information for 14 seconds before going silent.)

    One of the two rovers now on Mars — Curiosity — has established once and for all time that Mars was entirely habitable in its early life. It has drilled into the planet numerous times and has tested the samples for essential-for-life carbon organic compounds (which it found.) It also has detected clear evidence of long-ago and long-standing lakes and rivers. And it measured radiation levels at the surface over years to help determine how humans might one day survive there.

    I think it’s fair to say that Curiosity has advanced an understanding of the history and current realities of Mars more than any other mission, and perhaps more than all the others combined.

    Equally important, the almost two-thousand pound rover was delivered to the surface via a new landing technique called the “sky crane.” If your goal is to some day land a human on Mars, then learning how to deliver larger and larger payloads is essential because a capsule for astronauts would weigh something like 80,000 pounds.

    The European Space Agency, as well as the Russians and Chinese, have tried to send landers to Mars in recent years, but with no success.

    And as for Curiosity, it has been exploring Mars now for almost five years — well past its nominal mission lifetime.

    3
    This Cassini image of Saturn is the of 21 frames across 7 footprints, filtered in groups of red, green, and blue. The sequence was captured by Cassini over the course of 90-plus minutes on the morning of October 28th. Like many premier images from space, an individual — here Ian Regan — used the public access information and images provided by NASA of all its missions to produce the mosaic. (NASA/JPL-Caltech/Space Science Institute/Ian Regan).

    NASA/ESA/ASI Cassini-Huygens Spacecraft

    NASA missions to Saturn and Jupiter have sent back images that are startling in their beauty and overflowing in their science. And they have found unexpected features that could some day lead to a discovery of extraterrestrial life in our solar system.

    The most surprising discovery was at Saturn’s moon Enceladus, which turns out to be spewing water vapor into space from its south pole region. This water contains, among other important compounds, those organic building blocks of life, as well as evidence that the plumes are generated by hydrothermal heating of the ocean under the surface of the moon.

    In other words, there is a global ocean on Enceladus and at the bottom of it water and hot rock are in contact and are reacting in a way that, on Earth at least, would provide an environment suitable for life. And then the moon is spitting out the water to make it quite possible to study that water vapor and whatever might be in it.

    If the last decades are a guide, up-close study of these icy moons is a challenge and opportunity that the United States alone — sometimes in collaboration with European partners — has shown the ability and appetite to embrace make happen.

    4
    NASA’s Cassini spacecraft completed its deepest-ever dive through the icy plume of Enceladus on Oct. 28, 2015. (NASA/JPL-Caltech).

    The plumes were investigated and even traversed by the Cassini spacecraft, which is a joint NASA-ESA mission [with ASI]. The primary ESA contribution was the Huygens probe that descended to Titan in 2005. To people in the space science community, these kind of collaborations — generally with European space agencies — allow for more complex missions and good international relations.

    Plumes of water vapor have also been tentatively discovered identified on Jupiter’s moon, Europa. The data for the discovery came mostly from the Hubble Space Telescope, and is already a part of the previously approved NASA future. The Europa Clipper is scheduled to launch in the 2020s, to orbit the moon and intensively examine the solar system world believed most likely to contain life.

    NASA/Europa Clipper

    The plumes would be coming from another large global ocean under a thick shell of ice, a body of water understood to be much older and much bigger than that of Enceladus. Clearly, having some of that H2O available for exploration without going through the thick ice shell would be an enormous obstacle eraser.

    A follow-up Europa lander mission has been studied and got favorable reviews from a NASA panel, but was not funded by the Trump Administration. Several follow-up Enceladus life-detection missions are currently under review.

    5
    This very high resolution mosaic image of the Pillars of Creation was taken by the Hubble Space Telescope in 2014 and is a reprise of the iconic image first taken in 1995. The pillars are part of a nebula some 6,500-7000 light-years from Earth, and are immense clouds of gas and dust where stars are born. (NASA).

    NASA/ESA Hubble Telescope

    .

    I think one could make a strong case that the Hubble Space Telescope has been the most transformative, productive and admired piece of space technology ever made.

    For more than two decades now it has been the workhorse of the astrophysics, cosmology and exoplanet communities, and has arguably produced more world-class stunning images than Picasso. In terms of exploring the cosmos and illustrating some of what’s out there, it has no competition.

    There is little point to describing its specific accomplishments in terms of discovery because they are so many. Suffice it to say that a collection of published science papers using Hubble data would be very, very thick.

    And because of past NASA, White House and congressional commitment to space science, the over-budget and long behind-schedule James Webb Space Telescope is now on target to launch late next year.

    NASA/ESA/CSA Webb Telescope annotated

    The Webb will potentially be as revelatory as the Hubble, or even more so in terms of understanding the early era of the universe, the nature and origin of ubiquitous dark matter, and the composition of exoplanets.

    Preliminary planning for the great observatory for the 2030s is underway now, and nobody knows whether funding for something as ambitious will be available.

    NASA/WFIRST

    7
    The era of directly imaging exoplanets has only just begun, but the science and viewing pleasures to come are appealingly apparent. This evocative movie of four planets more massive than Jupiter orbiting the young star HR 8799 is a composite of sorts, including images taken over seven years at the W.M. Keck observatory in Hawaii. (Jason Wang/University of California, Berkeley and Christian Marois, National Research Council of Canada’s Herzberg Institute of Astrophysics. )


    Keck Observatory, Mauna Kea, Hawaii, USA

    Many of the early exoplanet discoveries were made by astrophysicists at ground-based observatories, and were made by both American, European and Canadian scientists. NASA’s Spitzer Space Telescope and others played a kind of supporting role for the agency, but that all changed with the launch of NASA’s Kepler Space Telescope.

    NASA/Spitzer Telescope

    .

    NASA/Kepler Telescope

    From 2009 to today, the Kepler has identified more than 4,000 exoplanet candidates with more than 2,400 confirmed planets, many of which are rocky like Earth. Of roughly 50 near-Earth size habitable zone candidates detected by Kepler, more than 30 have been verified.

    The census provided by Kepler, which looked fixedly at only one small part of the deep sky for four years until mechanical, led to the consensus conclusion that the Milky Way alone is home to billions of planets and that many of them are rocky and in the habitable zone of their host stars.

    In other words, Kepler made enormous progress in defining the population of exoplanets likely to exist out there — a wild menagerie of objects very different from what might have been expected, and in systems very different as well.

    Two additional NASA observatories designed to detect and study exoplanets are scheduled to launch in the next decade.

    Given the number of references to our moon in Pence’s Kennedy Space Station speech — and the enormous costs of the also often referenced humans-to-Mars idea — my bet is that moon landings and perhaps a “colony” will be the Administration’s human space exploration project of choice.

    I say this because it is achievable, with NASA rockets and capsules under construction and the fast-growing capabilities of commercial space competitors. We have, after all, proven that astronauts can land and survive on the moon, and a return there would be much less expensive than sending a human to Mars and back. (I’m also skeptical that such a trip to Mars will be technically feasible any time in the foreseeable future, though I know that others strongly disagree.)

    As readers of Many Worlds may remember, I’m a fan of a human spaceflight project championed by former astronaut and head of NASA’s Science Directorate John Grunsfeld to assemble a huge observatory in space designed to seriously look for life around distant stars. This plan is innovative, would give NASA and astronauts an opportunity learn how to live and work in deep space, and would provide another science gem.

    But here is why I think a moon colony is going to be the choice: Russia, China and the Europeans have all announced tentative plans to build moon colonies in the next decade or two. So for primarily strategic, competitive and national security reasons, it seems likely that this kind of “new frontier” is what the administration has in mind.

    After all, Pence also said in his speech at the KSC that “Under President Donald Trump, American security will be as dominant in the heavens as we are here on Earth.”

    Setting up an American moon colony would be very costly in dollars, time and focus, but it’s not necessarily a bad thing. Given that a pie can be sliced just so many ways, however, it’s pretty clear that a major moon colony project would end up taking a significant amount of funding away from space science missions.

    Returning to the moon and even setting up a colony is not, however, an example of American leadership. Rather, it would constitute a decision for the United States and NASA to, in effect, follow the pack.

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 2:48 pm on July 6, 2017 Permalink | Reply
    Tags: , , , , Certain Big, Charged Molecules Are Universal to Life. Can They Help Detect It Elsewhere in the Solar System?, , Many Worlds   

    From Many Worlds: “Certain Big, Charged Molecules Are Universal to Life. Can They Help Detect It Elsewhere in the Solar System?” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-07-06
    Marc Kaufman

    1
    NASA’s Cassini spacecraft completed its deepest-ever dive through the icy plume of Enceladus on Oct. 28, 2015. The spacecraft did not have instruments that could detect life, but missions competing for NASA New Frontiers funding will — raising the thorny question of how life might be detected. (NASA/JPL-Caltech)

    As NASA inches closer to launching new missions to the Solar System’s outer moons in search of life, scientists are renewing their focus on developing a set of universal characteristics of life that can be measured.

    There is much debate about what might be considered a clear sign of life, in part, because there are so many definitions separating the animate from the inanimate.

    NASA’s prospective missions to promising spots on Europa, Enceladus and Titan have their individual approaches to detecting life, but one respected voice in the field says there is a better way that’s far less prone to false positives.

    Noted chemist and astrobiologist Steven Benner says life’s signature is not necessarily found in the presence of particular elements and compounds, nor in its effects on the surrounding environment, and is certainly not something visible to the naked eye (or even a sophisticated camera).

    Rather, life can be viewed as a structure, a molecular backbone that Benner and his group, Foundation for Applied Molecular Evolution (FfAME), have identified as the common inheritance of all living things. Its central function is to enable what origin-of-life scientists generally see as an essential dynamic in the onset of life and its increased complexity and spread: Darwinian evolution via transfer of information, mutation and the transfer of those mutations.

    “What we’re looking for is a universal molecular bio-signature, and it does exist in water,” says Benner. “You want a genetic molecule that can change physical conditions without changing physical properties — like DNA and RNA can do.”

    2
    Steven Benner, director of the Foundation for Applied Molecular Evolution or FfAME. (SETI)

    Looking for DNA or RNA on an icy moon, or elsewhere would presuppose life like our own — and life that has already done quite a bit of evolving.

    A more general approach is to find a linear polymer (a large molecule, or macromolecule, composed of many repeated subunits, of which DNA and RNA are types) with an electrical charge. That, he said, is a structure that is universal to life, and it can be detected.

    As described in a recent paper that Benner’s group published in the journal Astrobiology: “the only molecular systems able to support Darwinian information are linear polymers that have a repeating backbone charge. These are called ‘polyelectrolytes.’

    “These data suggest that polyelectrolytes will be the genetic molecules in all life, no matter what its origin and no matter what the direction or tempo of its natural history, as long as it lives in water.”

    Through years of experimentation, Benner and others have found that electric charges in these crucial polymers, or “backbones,” of life have to repeat. If they are a mixture of positive and negative charges, then the ability to pass on changing information without the structure itself changing is lost.

    And as a result, Benner says, detecting these charged, linear and repeating large molecules is potentially quite possible on Europa or Enceladus or wherever water is found. All you have to do is expose those charged and repeating molecular structures to an instrument with the opposite charge and measure the reaction.

    3
    Polyelectrolytes are long-chain, molecular semiconductors, whose backbones contain electrons. The structure and composition of the polyelectrolytes confers an ability to transfer electric charge and the energy of electronic excited states over distance. (Azyner Group, UCSC)

    James Green, director of NASA’s Planetary Sciences division, sees values in this approach.

    “Benner’s polyelectrolyte study is fascinating to me since it provides our scientists another critical discussion point about finding life with some small number of experiments,” he says.

    “Finding life is very high bar to cross; it has to metabolize, reproduce, and evolve — all of which I can’t develop an experiment to measure on another planet or moon. If it doesn’t talk or move in front of the camera we are left with developing a very challenging set of instruments that can only measure attributes. So polyelectrolytes are one more to consider.”

    Benner has been describing his universal molecular bio-signature to leaders of the groups competing for New Frontiers missions, which fill the gap between smaller Discovery missions and large flagship planetary missions. It’s taken a while but due to his efforts over several years, he notes that interest seems to be growing in incorporating his findings.

    4
    Astrobiologist Chris McKay at NASA’s Ames Research Center. (IDG News Service)

    In particular, Chris McKay, a prominent astrobiologist at NASA’s Ames Research Center and a member of one of the New Frontiers Enceladus proposal teams, says he thinks there is merit to Benner’s idea.

    “The really interesting aspect of this suggestion is that new technologies are now available for sequencing DNA that can be generalized to read any linear molecule,” McKay writes in an email.

    In other words, they can detect any polyelectrolytes.

    Other teams are confident that their own kinds of life detection instruments can do the job. Morgan Cable, deputy project scientist of the Enceladus Life Finder proposal, she says her team has great confidence in its four-pronged approach. A motto of the mission on some of its written material is: “If Encedadus has life, we will find it.”

    The package includes instruments like mass spectrometers able to detect large molecules associated with life; measurements of energy gradients that allow life to be nourished; detection of isotopic signatures associated with life; and identification of long carbon chains that serve as membranes to house the components of a cell.

    “Not one but all four indicators have to point to life to make a potential detection,” Cable says.

    NASA is winnowing down 12 proposals by late this year, so, Benner’s ideas could play a role later in the process as well. NASA’s goal is to select its next New Frontiers mission in about two years, with launch in the mid-2020s.

    The Europa Clipper orbiter mission is tentatively scheduled to launch in 2022, but its companion lander has been scrubbed for now by the Trump administration.

    Nonetheless, NASA put out a call last month for instruments that might one day sample the ice of Europa. Benner is once more hoping that his theory of polyelectrolytes as the key to identifying life in water or ice will be considered and embraced.

    5
    These composite images show a suspected plume of material erupting two years apart from the same location on Jupiter’s icy moon Europa. Both plumes, photographed in UV light by Hubble, were seen in silhouette as the moon passed in front of Jupiter. Europa is a major focus of the search for life beyond Earth. (NASA/ESA/STScI/USGS)

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 4:21 pm on June 24, 2017 Permalink | Reply
    Tags: , , , , , Extremeophiles, Many Worlds, MatISSE - Maturation of Instruments for Solar System Exploration, Oxford Nanopore, , SETG - The Search for Extraterrestrial Genomes   

    From Many Worlds: “In Search of Panspermia (and Life on Icy Moons)” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-06-23
    Marc Kaufman

    1
    Early Earth, like early Mars and no doubt many other planets, was bombarded by meteorites and comets. Could they have arrived “living” microbes inside them?

    When scientists approach the question of how life began on Earth, or elsewhere, their efforts generally involve attempts to understand how non-biological molecules bonded, became increasingly complex, and eventually reached the point where they could replicate or could use sources of energy to make things happen. Ultimately, of course, life needed both.

    Researchers have been working for some time to understand this very long and winding process, and some have sought to make synthetic life out of selected components and energy. Some startling progress has been made in both of these endeavors, but many unexplained mysteries remain at the heart of the processes. And nobody is expecting the origin of life on Earth (or elsewhere) to be fully understood anytime soon.

    To further complicate the picture, the history of early Earth is one of extreme heat caused by meteorite bombardment and, most important, the enormous impact some 4.5 billion years of the Mars-sized planet that became our moon. As a result, many early Earth researchers think the planet was uninhabitable until about 4 billion years ago.

    Yet some argue that signs of Earth life 3.8 billion years ago have been detected in the rock record, and lifeforms were certainly present 3.5 billion years ago. Considering the painfully slow pace of early evolution — the planet, after all, supported only single-cell life for several billion years before multicellular life emerged — some researchers are skeptical about the likelihood of DNA-based life evolving in the relatively short window between when Earth became cool enough to support life and the earliest evidence of actual life.

    2
    A DNA helix animation. Life on Earth is based on DNA, and some researchers have been working on ways to determine whether DNA life also exists on Mars or elsewhere in the solar system.

    So what else, from a scientific as opposed to a religious perspective, might have set into motion the process that made life out of non-life?

    One long considered yet generally quickly dismissed answer is getting new attention and a little more respect. It invokes panspermia, the sharing of life via meteorites from one planet to another, or delivery by comet.

    In this context, the question generally raised is whether Earth might have been seeded by early Martian life (if it existed). Mars, it is becoming increasingly accepted, was probably more habitable in its early period than Earth. But panspermia inherently could go the other way as well, or possibly even between solar systems.

    A team of prominent scientists at MIT and Harvard are sufficiently convinced in the plausibility of panspermia that they have spent a decade, and a fair amount of NASA and other funding, to design and produce an instrument that can be sent to Mars and potentially detect DNA or more primitive RNA.

    In other words, life not only similar to that on Earth, but actually delivered long ago from Earth. It’s called the The Search for Extraterrestrial Genomes, or SETG.

    Gary Ruvkun is one of those researchers, a pioneering molecular biologist at Massachusetts General Hospital and professor of genetics at Harvard Medical School.

    I heard him speaking recently at a Space Sciences Board workshop on biosignatures, where he described the real (if slim) possibility that DNA or RNA-based life exists now on Mars, and the instrument that the SETG group is developing to detect it should it be there.

    3
    Did meteorites spread life between planets, and maybe even solar systems? Some pretty distinguished people think that it may well have happened. This illustration is an artist’s rendering of the comet Siding Spring approaching Mars in 2015. (NASA)

    The logic of panspermia — or perhaps “dispermia” if between but two planets — is pretty straight-forward, though with some significant question marks. Both Earth and Mars, it is well known, were pummeled by incoming meteorites in their earlier epochs, and those impacts are known to have sufficient force to send rock from the crash site into orbit.

    Mars meteorites have been found on Earth, and Earth meteorites no doubt have landed on Mars. Ruvkun said that recent work on the capacity of dormant microbes to survive the long, frigid and irradiated trip from planet to planet has been increasingly supportive.

    “Earth is filled with life in every nook and cranny, and that life is wildly diverse,” he told the workshop. “So if you’re looking for life on Mars, surely the first thing to look for is life like we find on Earth. Frankly, it would be kind of stupid not to.”

    The instrument being developed by the group, which is led by Ruvkun and Maria Zuber, MIT vice president for research and head of the Department of Earth, Atmospheric and Planetary Sciences. It would potentially be part of a lander or rover science package and would search DNA or RNA, using techniques based on the exploding knowledge of earthly genomics.

    The job is made easier, Ruvkun said, by the fact that the basic structure of DNA is the same throughout biology. What’s more, he said, there about 400 specific genes sequences “that make up the core of biology — they’re found in everything from extremeophiles and bacteria to worms and humans.”

    Those ubiquitous gene sequences, he said, were present more than 3 billion years ago in seemingly primitive lifeforms that were, in fact, not primitive at all. Rather, they had perfected some genetic pathways that were so good that they still used by most everything alive today.

    And how was it that these sophisticated life processes emerged not all that long (in astronomical or geological terms) after Earth cooled enough to be habitable? “Either life developed here super-fast or it came full-on as DNA life from afar,” Ruvkun said. It’s pretty clear which option he supports.

    Ruvkun said that the rest of the SETG team sees that kind of inter-planetary transfer — to Mars and from Mars — as entirely plausible, and that he takes panspermia a step forward. He thinks it’s possible, though certainly not likely nor remotely provable today, that life has been around in the cosmos for as long as 10 billion years, jumping from one solar system and planet to another. Not likely, but at idea worth entertaining.

    4
    A state-of-the-art instrument for reading DNA sequences in the field. The MIT/Harvard team is working with the company that makes it, and several others, on refining how it would do that kind of sequencing of live DNA on Mars. The extremely high-tech thumb drive weighs about 3 ounces. (Oxford Nanopore)

    Maria Zuber of MIT, who was the PI for the recent NASA GRAIL mission to the moon, has been part of the SETG team since near its inception, and MIT research scientist Christopher Carr is the project manager. Zuber said it was a rather low-profile effort at the start, but over the years has attracted many students and has won NASA funding three times including the currently running Maturation of Instruments for Solar System Exploration (MatISSE) grant.

    “I have made my career out of doing simple experiments. if want to look for life beyond earth helps to know what you’re looking for.

    “We happen to know what life on Earth is like– DNA based or possibly RNA-based as Gary is looking for as well. The point is that we know what to look for. There are so many possibilities of what life beyond Earth could be like that we might as well test the hypothesis that it, also, is DNA based. It’s a low probability result, but potentially very high value.”

    DNA sequencing instruments like the one her team is developing are taken to the field regularly by thousands of researchers, including some working with with SETG. The technology has advanced so quickly that they can pick up a sample in a marsh or desert or any extreme locale and on the spot determine what DNA is present. That’s quite a change from the pain-staking sequencing done painstakingly by graduate students not that long ago.

    Panspermia, Zuber acknowledged, is a rather improbable idea. But when nature is concerned, she said “I’m reticent to say anything is impossible. After all, the universe is made up of the same elements as those on Earth, and so there’s a basic commonality.”

    Zuber said the instrument was not ready to compete for a spot on the 2020 mission to Mars, but she expects to have a sufficiently developed one ready to compete for a spot on the next Mars mission. Or perhaps on missions to Europa or the plumes of Enceladus.

    The possibility of life skipping from planet to planet clearly fascinates both scientists and the public. You may recall the excitement in the mid 1990s over the Martian meteorite ALH84001, which NASA researchers concluded contained remnants of Martian life. (That claim has since been largely refuted.)

    Of the roughly 61,000 meteorites found on Earth, only 134 were deemed to be Martian as of two years ago. But how many have sunk into oceans or lakes, or been lost in the omnipresence of life on Earth? Not surprisingly, the two spots that have yielded the most meteorites from Mars are Antarctica and the deserts of north Africa.

    And when thinking of panspermia, it’s worthwhile to consider the enormous amount of money and time put into keeping Earthly microbes from inadvertently hitching a ride to Mars or other planets and moons as part of a NASA mission.

    The NASA office of planetary protection has the goal of ensuring, as much as possible, that other celestial bodies don’t get contaminated with our biology. Inherent in that concern is the conclusion that our microbes could survive in deep space, could survive the scalding entry to another planet, and could possibly survive on the planet’s surface today. In other words, that panspermia (or dispermia) is in some circumstances possible.

    Testing whether a spacecraft has brought Earth life to Mars is actually another role that the SETG instrument could play. If a sample tested on Mars comes back with a DNA signature result exactly like one on Earth–rather one that might have come initially from Earth and then evolved over billions of years– then scientists will know that particular bit of biology was indeed a stowaway from Earth.

    Rather like how a very hardy microbe inside a meteorite might have possibly traveled long ago.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 7:08 am on June 2, 2017 Permalink | Reply
    Tags: , , , , , Many Worlds, , Nobel laureate Jack Szostak, Nobel Laureate Jack Szostak: Exoplanets Gave The Origin of Life Field a Huge Boost   

    From Many Worlds: “Nobel Laureate Jack Szostak: Exoplanets Gave The Origin of Life Field a Huge Boost” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-06-02
    Marc Kaufman

    1
    Jack Szostak, Nobel laureate and pioneering researcher in the origin-of-life field, was the featured speaker at a workshop this week at the Earth-Life Science Institute (ELSI) in Tokyo. One goal of his Harvard lab is to answer this once seemingly impossible question: was the origin of life on Earth essentially straight-forward and “easy,” or was it enormously “hard” and consequently rare in the universe. (Nerissa Escandar)

    Sometimes tectonic shifts in scientific disciplines occur because of discoveries and advances in the field. But sometimes they occur for reasons entirely outside the field itself. Such appears to be case with origins-of-life studies.

    Nobel laureate Jack Szostak was recently in Tokyo to participate in a workshop at the Earth-Life Science Institute (ELSI) on “Reconstructing the Phenomenon of Life To Retrace the Emergence of Life.”

    The talks were technical and often cutting-edge, but the backstory that Szostak tells of why he and so many other top scientists are now in the origins of life field was especially intriguing and illuminating in terms of how science progresses.

    Those ground-shifting discoveries did not involve traditional origin-of-life questions of chemical transformations and pathways. They involved exoplanets.

    “Because of the discovery of all those exoplanets, astronomy has been transformed along with many other fields,” Szostak said after the workshop.

    “We now know there’s a large range of planetary environments out there, and that has stimulated a huge amount of interest in where else in the universe might there be life. Is it just here? We know for sure that lots of environments could support life and we also would like to know: do they?

    “This has stimulated much more laboratory-based work to try to address the origins question. What’s really important is for us to know whether the transition from chemistry to biology is easy and can happen frequently and anywhere, or are there one or many difficult steps that make life potentially very rare?”

    In other words, the explosion in exoplanet science has led directly to an invigorated scientific effort to better understand that road from a pre-biotic Earth to a biological Earth — with chemistry that allows compounds to replicate, to change, to surround themselves in cell walls, and to grow ever more complex.

    With today’s increased pace of research, Szostak said, the chances of finding some solid answers have been growing. In fact, he’s quite optimistic that an answer will ultimately be forthcoming to the question of how life began on Earth.

    “The field is making real progress in understanding the pathway from pre-biotic chemistry to the earliest life,” Szostak told. “We think this is a difficult but solvable problem.”

    And any solution would inevitably shed light on both the potential make-up and prevalence of extraterrestrial life.

    2
    This artist’s concept depicts select planetary discoveries made to date by NASA’s Kepler space telescope. (NASA/W. Stenzel)

    NASA/Kepler Telescope

    Whether it’s ultimately solvable or not, that pathway from non-life to life would appear to be nothing if not winding and complex. And since it involves trying to understand something that happened some 4 billion years ago, the field has had its share of fits and starts.

    It is no trivial fact that probably the biggest advance in modern origin-of-life science — the renown Miller-Urey experiment that produced important-for-life amino acids out of a sparked test tube filled with gases then believed to be prevalent on early Earth — took place more than 60 years ago.

    Much has changed since then, including an understanding that the gases used by Miller and Urey most likely did not reflect the early Earth atmosphere. But no breakthrough has been so dramatic and paradigm shifting since Miller-Urey. Scientists have toiled instead in the challenging terrain of how and why a vast array of chemicals associated with life just might be the ones crucial to the enterprise.

    But what’s new, Szostak said, is that the chemicals central to the pathway are much better understood today. So, too, are the mechanisms that help turn non-living compounds into self-replicating complex compounds, the process through which protective yet fragile cell walls can be formed, and the earliest dynamics involved in the essential task of collecting energy for a self-replicating chemical system to survive.

    2
    The simple protocells that may have enabled life to develop four billion years ago consist of only genetic material surrounded by a fatty acid membrane. This pared down version of a cell—which has not yet been completely recreated in a laboratory—is thought to have been able to grow, replicate, and evolve. (Howard Hughes Medical Institute)

    This search for a pathway is a major international undertaking; a collective effort involving many labs where obstacles to understanding the origin-of-life process are being overcome one by one.

    Here’s an example from Szostak: The early RNA replicators needed the element magnesium to do their copying. Yet magnesium destroyed the cell membranes needed to protect the RNA.

    A possible solution was to find potential acids to bond with magnesium and protect the membranes, while still allowing the element to be available for RNA chemistry. His team found that citric acid, or citrate, worked well when added to the cells. Problem solved, in the lab at least.

    The Szostak lab at Harvard University and the Howard Hughes Medical Institute has focused on creating “protocells” that are engineered by researchers yet can help explain how origin-of-life processes may have taken place on the early Earth.

    6

    Their focus, Szostak said, is on “what happens when we have the right molecules and how do they get together to form a cell that can grow and divide.”

    It remains a work in progress, but Szostak said much has been accomplished. Protocells have been engineered with the ability to replicate, to divide, to metabolize food for energy and to form and maintain a protective membrane.

    The perhaps ultimate goal is to develop a protocell with with the potential for Darwinian evolution. Were that to be achieved, then an essentially full system would have been created.

    3
    How did something alive emerge from a non-living world. It’s a question as old as humanity, but may in time prove to be solvable. Here blue-green algae in Morning Glory Pool, Yellowstone National Park, Wyoming.

    Just as the discovery of a menagerie of exoplanets jump-started the origin of life field, it also changed forever its way of doing business.

    No longer was the field the singular realm of chemists, but began to take in geochemists, planetary scientists, evolutionary biologists, atmospheric scientists and even astronomers (one of whom works in Szostak’s lab.)

    “A lot of labs are focused on different points in the process,” he said. “And because origins are now viewed as a process, that means you need to know how planets are formed and what happens on the planetary surface and in the atmospheres when they’re young.

    “Then there’s the question of essential volatiles (such as nitrogen, water, carbon dioxide, ammonia, hydrogen, methane and sulfur dioxide); when do they come in and are they too much or not enough.”

    These were definitely not issues of importance to Stanley Miller and Harold Urey when they sought to make building blocks of life from some common gases and an electrical charge.

    But seeing the origin of life question as a long pathway as opposed to a singular event leaves some researchers cold. With so many steps needed, and with the precisely right catalysts and purified compounds often essential to allow the next step take place, they argue that these pathways produced in a chemistry lab are unlikely to have anything to do with what actually happened on Earth.

    Szostak disagrees, strongly. “That just not true. The laws of chemistry haven’t changed since early Earth, and what we’re trying to understand is the fundamental chemistry of these compounds associated with life so we can work out plausible pathways.”

    If and when a plausible chemical pathway is established, Szostak said, it would then be time to turn the scientific process around and see if there is a possible model for the presence of the needed pathway ingredients on early Earth.

    And that involves the knowledge of geochemists, researchers expert in photochemistry and planetary scientists who have insight into what conditions were like at a particular time.

    4
    Szostak and David Deamer, an evolutionary biologist at the University of California, Santa Cruz, at the ELSI origins workshop.

    Deamer supports the view that life on Earth may well have begun in and around hydrothermal springs on land. That’s where essential compounds could concentrate, where energy was present and organic compounds on interstellar dust could have landed, as they do today. (Nerissa Escandar)

    Given the work that Szostak, his group and others have done to understand possible pathways that lead from simple starting materials to life, the inevitable question is whether there was but one pathway or many.

    Szostak is of the school that there may well have been numerous pathways that resulted in life, although only one seems to have won out. He bases his view, in part at least, on a common experience in his lab. He and his colleagues can bang their collective heads together for what seems forever on a hard problem only to later find there was not one or two but potentially many answers to it.

    An intriguing implication of this “many pathways” hypothesis is that it would seemingly increase the possibility of life starting beyond Earth. The underlying logic of Szostak’s approach is to find how chemicals can interact to form life-like and then more complex living systems within particular environments. And those varied environments could be on early Earth or on a planet or moon far away.

    “All of this looked very, very hard at the start, trying to identify the pathways that could lead to life. And sure, there are gaps remaining in our understanding. But we’ve solved a lot of problems and the remaining big problems are a rather small number. So I’m optimistic we’ll find the way.”

    “And when we get discouraged about our progress I think, you know, life did get started here. And actually it must quite simple. We’re just not smart enough to see the answer right away.

    “But in the end it generally turns out to be simple and you wonder 20 years later, why didn’t we think of that before?”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 10:09 am on May 22, 2017 Permalink | Reply
    Tags: , , , , , Getting Real About the Oxygen Biosignature, Many Worlds   

    From Many Worlds: “Getting Real About the Oxygen Biosignature” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-05-22
    Marc Kaufman

    1
    Oxygen, which makes up about 21 percent of the Earth atmosphere, has been embraced as the best biosignature for life on faraway exoplanets. New research shows that detecting distant life via the oxygen biosignature is not so straight-forward, though it probably remains the best show we have. (NASA)

    I remember the first time I heard about the atmospheres of distant exoplanets and how could and would let us know whether life was present below.

    The key was oxygen or its light-modified form, ozone. Because both oxygen and ozone molecules bond so quickly with other molecules — think rust or iron oxide on Mars, silicon dioxide in the Earth’s crust — it was said that oxygen could only be present in large and detectable quantities if there was a steady and massive source of free oxygen on the planet.

    On Earth, this of course is the work of photosynthesizers such as planets, algae and cyanobacteria, which produce oxygen as a byproduct.

    2
    An image of Cyanobacteria, Tolypothrix.
    Date 22 January 2013
    Author Matthewjparker

    No other abiotic, or non-biological, ways were known at the time to produce substantial amounts of atmospheric oxygen, so it seemed that an oxygen signal from afar would be a pretty sure sign of life.

    But with the fast growth of the field of exoplanet atmospheres and the very real possibility of having technology available in the years ahead that could measure the components of those atmospheres, scientists have been busy modelling exoplanet formations, chemistry and their atmospheres.

    One important goal has been to search for non-biological ways to produce large enough amounts of atmospheric oxygen that might fool us into thinking that life has been found below.

    And in recent years, scientists have succeeded in poking holes in the atmospheric oxygen-means-life scenario.

    3
    Oxygen bonds quickly with many other molecules. That means has to be resupplied regularly to be present as O2 in an atmosphere . On Earth, O2 is mostly a product of biology, but elsewhere it might be result of non-biological processes. Here is an image of oxygen bubbles in water.

    Especially researchers at the University of Washington’s Virtual Planetary Laboratory (VPL) have come up with numerous ways that exoplanets atmospheres can be filled (and constantly refilled) with oxygen that was never part of plant or algal or bacteria photo-chemistry.

    In other words, they found potential false positives for atmospheric oxygen as a biosignature, to the dismay of many exoplanet scientists.

    In part because she and her own team were involved in some of these oxygen false-positive papers, VPL director Victoria Meadows set out to review, analyze and come to some conclusions about what had become the oxygen-biosignature problem.

    The lengthy paper (originally planned for 6 pages but ultimately 34 pages because research from so many disciplines was coming in) was published last month in the journal Astrobiology. It seeks to both warn researchers about the possibilities of biosignature false-positives based on oxygen detection, and then it assures them that there are ways around the obstacles.

    “There was this view in the community that oxygen could only be formed by photosynthesis, and that no other process could make O2,” Meadows told me. “It was a little simplistic. We now see the rich complexity of what we are looking at, and are thinking about the evolutionary paths of these planets.

    4
    Artist’s impression of the exoplanet GJ 1132 b, which orbits the red dwarf star GJ 1132. Earlier this year, astronomers managed to detect the atmosphere of this Earth-sized planet and have determined that water and methane are likely prevalent in the atmosphere. (Max Planck Institute for Astronomy)

    “What I see is a maturing of the field. We have models that show plausible ways for oxygen to be produced without biology, but that doesn’t mean that oxygen is no longer an important biosignature.

    “It is very important. But it has to be seen and understood in the larger context of what else is happening on the planet and its host star.”

    Before moving forward, perhaps we should look back a bit at the history of oxygen on Earth.

    For substantial parts of our planet’s history there was only minimal oxygen in the atmosphere, and life survived in an anaerobic environment. When exactly oxygen went from a small percentage of the atmosphere to 21 percent of the atmosphere is contested, but there is broader agreement about the source of the O2 in the atmosphere. The source was photosynthesis, most importantly coming from cyanobacteria in the oceans.

    As far back as four billion years ago, photosynthesis occurred on Earth based on the capturing of the energy of near infrared light by sulfur-rich organisms, but it did not involve the release of oxygen as a byproduct.

    5
    A chart showing the percentage rise in oxygen in Earth’s atmosphere over the past 3.8 billion years. The great oxidation event occurred some 2.3 billion years ago, but it took more than a billion additional years for the build-up to have much effect on the composition of the planet’s atmosphere.

    Then came the the rise of cyanobacteria in the ocean and their production of oxygen. With their significantly expanded ability to use photosynthesis, this bacterium was able to generate up to 16 times more energy than its counterparts, which allowed it to out-compete and explode in reproduction.

    It took hundreds of millions of years more, but that steady increase in the cyanobacteria population led to what is called the “Great Oxidation Event” of some 2.3 billion years ago, when oxygen levels began to really climb in Earth’s atmosphere. They did level off and remained well below current levels for another billion years, but then shot up in the past billion years.

    As Meadows (and others) point out, this means that life existed on Earth for at least two billion years years without producing a detectable oxygen biosignature. It’s perhaps the ultimate false negative.

    But as biosignatures go, oxygen offers a lot. Because it bonds so readily with other elements and compounds, it remains unbonded or “free” O2 only if it is being constantly produced. On Earth, the mode of production is overwhelmingly photosynthesis and biology. What’s more, phototrophs — organism that manufacture their own food from inorganic substances using light for energy — often produce reflections and seasonally dependent biosignatures that can serve as secondary confirmations of biology as the source for abundant O2 in an atmosphere.

    So in a general way, it makes perfect sense to think that O2 in the atmosphere of an exoplanet would signify the presence of photosynthesis and life.

    The problem arises because other worlds out there orbiting stars very different than our own can have quite different chemical and physical dynamics and evolutionary histories, with results at odds with our world.

    For instance, when it comes to the non-biological production of substantial amounts of oxygen that could collect in the atmosphere, the dynamics involved could include the following:

    Perhaps the trickiest false positive involves the possible non-biological release of O2 via the photolysis of water — the breaking apart of H2O molecules by light. On Earth, the water vapor in the atmosphere condenses into liquids after reaching a certain height and related temperature, and ultimately falls back down to the surface. How and why that happens is related to the presence of large amounts of nitrogen in our atmosphere.

    But what if an exoplanet atmosphere doesn’t have a lot of an element like nitrogen that allows the water to condense? Then the water would rise into the stratosphere, where it would be subject to intense UV light,. The molecule would be split, and an H atom would fly off into space — leaving behind large amounts of oxygen that had nothing to do with life. This conclusion was reached by Robin Wordsworth and Raymond Pierrehumbert of the University of Chicago and was published by the The Astrophysical Journal.

    Another recently proposed mechanism to generate high levels of abiotic oxygen, first described by Rodrigo Luger and Rory Barnes of Meadow’s VPL team, focuses on the effects of the super-luminous phase of young stars on any rocky planets that might be orbiting them.

    Small-mass M dwarfs in particular can burn much brighter when they are young, exposing potential planets around those stars to very high levels of radiation for as long as one billion years.

    Modeling suggests that during this super-luminous phase a terrestrial planet that forms within what will become the main sequence habitable zone around an M dwarf star may lose up to several Earth ocean equivalents of water due to evaporation and hydrodynamic escape, and this can lead to generation of large amounts of abiotic O2 via the same H2O photolysis process.

    Non-biological oxygen can also build up on an exoplanet, according to a number of researchers, if the host star sends out a higher proportion of far ultraviolet light than near ultraviolet. The dynamics of photo-chemistry are such, they argue, that the excess far ultraviolet radiation would split CO2 to an extent that O2 would build up in the atmosphere.

    There are other potential scenarios that would produce an oxygen false positive, and almost all of them involve radiation from the host star driving chemistry in the planet’s atmosphere, with the planetary environment then allowing O2 to build up. While some of these false positive mechanisms can produce enough oxygen to make a big impact on their planets, some may not produce enough to even be seen by telescopes currently being planned.

    As Meadows tells it, it was Shawn Domagal-Goldman of NASA Goddard and VPL who first brought the issue of oxygen false-positives to her attention. It was back in 2010 after he found an anomaly in his photo-chemical code results regarding atmospheric oxygen and exoplanets, and followed it. Since that initial finding, several other VPL researchers discovered new ways to produce O2 without life, and often while undertaking research focused on a different scientific goal.

    Six years later, when she was writing up a VPL annual report, it jumped out that the group (and others) had found quite a few potential oxygen false positives — a significant development in the field of biosignature detection and interpretation. That’s when she decided that an analysis and summary of the findings would be useful and important for the exoplanet community. “Never let it be said that administrative tasks can’t lead to inspiration!” she wrote to me.

    While Meadows does not downplay the new challenges to defining oxygen and ozone as credible biosignatures, she does say that these new understandings can be worked around.

    Some of that involves targeting planets and stars for observation that don’t have the characteristics known to produce abiotic oxygen. Some involves finding signatures of this abiotic oxygen that can be identified and then used to discard potential false positives. And perhaps most telling, the detection of methane alongside free oxygen in an exoplanet atmosphere would be considered a powerful signature of life.

    The official goal of Meadows’ VPL is to wrestle with this question: “How would we determine if an extrasolar planet were able to support life or had life on it already?”

    This has led her to a highly interdisciplinary approach, bringing together fifty researchers from twenty institutions. In addition to its leading role in the NASA Astrobiology Institute, the VPL is also part of a broad NASA initiative to bring together scientists from different locales and disciplines to work on issues and problems of exoplanet research — the Nexus for Exoplanet System Science, or NExSS.

    Given this background and these approaches, it is hardly surprising that Meadows would be among the first to see the oxygen-false positive issue in both scientific and collective terms.

    “I wanted the community to have some place to go to when thinking about O2 false positives,” she said. “We’re learning now about the complexity and richness of exoplanets, and this is essential for preparing to do the best job possible {in terms of looking for signs of life on exoplanets} when we get better and better observations to work with.”

    “This story needed to be told now. Forewarned is forearmed.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 11:22 am on May 15, 2017 Permalink | Reply
    Tags: , , , , , Many Worlds, , Planetary Protection is a “Wicked” Problem   

    From Many Worlds: “Planetary Protection is a “Wicked” Problem” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-05-15
    Marc Kaufman
    marc.kaufman@manyworlds.space

    1
    The Viking landers were baked for 30 hours after assembly, a dry heat sterilization that is considered the gold standard for planetary protection.

    NASA/Viking 1 Lander

    Before the baking, the landers were given a preliminary cleaning to reduce the number of potential microbial spores. The levels achieved with that preliminary cleaning are similar to what is now required for a mission to Mars unless the destination is an area known to be suitable for Martian life. In that case, a sterilizing equivalent to the Viking baking is required. (NASA)

    The only time that a formally designated NASA “life detection” mission was flown to another planet or moon was when the two Viking landers headed to Mars forty years ago.

    The odds of finding some kind of Martian life seemed so promising at the time that there was little dispute about how much energy, money and care should be allocated to making sure the capsule would not be carrying any Earth life to the planet. And so after the two landers had been assembled, they were baked at more than 250 °F for three days to sterilize any parts that would come into contact with Mars.

    Although the two landers successfully touched down on the Martian surface and did some impressive science, the life detection portion of the mission was something of a fiasco — with conflict, controversy and ultimately quite a bit of confusion.

    Clearly, scientists did not yet know enough about how to search for life beyond Earth and the confounding results pretty much eliminated life-detection from NASA’s missions for decades.

    But scientific and technological advances of the last ten years have put life detection squarely back on the agenda — in terms of future searches for fossil biosignatures on Mars and for potential life surviving in the oceans of Europa and Enceladus. What’s more, both NASA and private space companies talk seriously of sending humans to Mars in the not-too-distant future.

    With so many missions being planned, developed and proposed for solar system planets and moons, the issue of planetary protection has also gained a higher profile. It seems to have become more contentious and to some seems far less straight-forward as it used to be.

    A broad consensus appears to remain that bringing Earth life to another planet or moon, especially if it is potentially habitable, is a real possibility that is both scientifically and ethically fraught. But there are rumblings about just how much time, money and attention needs to be brought to satisfying the requirements of “planetary protection.”

    In fact, it has become a sufficiently significant question that the first plenary session of the recent Astrobiology Science Conference in Mesa, Arizona was dedicated to it. The issue, which was taken up in later technical sessions as well, was how to assess and weigh the risks of bringing Earth life to other bodies versus the benefits of potentially sending out more missions, more often and more cheaply.

    It is not a simple problem, explained Andrew Maynard, director of the Risk Innovation Lab at Arizona State University. Indeed, he told the audience of scientists that it was a “wicked problem,” a broadly used terms for issues that are especially complex and involve numerous issues and players.

    2
    A primary barrier to keeping microbes off spacecraft and instruments going to space is to build them in clean rooms, such as this one at JPL. These large rooms with filtered air do help lower the count of microbes on surfaces, but the bacteria are everywhere and further steps are essential. (NASA/JPL-Caltech)

    As he later elaborated to me, other “wicked” risk-benefit problems include gene editing and autonomous driving — both filled with great potential and serious potential downsides. Like travel to other planets and moons.

    “This is subjective,” Maynard said, “but I’d put planetary protection on the more wicked end of the spectrum. It combines individual priorities and ethics — what people and groups deeply believe is right — with huge uncertainties. That makes it something never really experienced before and so escalates all factors of wickedness.”

    Those groups include scientists (who very much don’t want Mars or another potentially habitable place to be contaminated with Earth life before they can get there), to advocates of greater space exploration (who worry that planetary protection will slow or eliminate some missions they very much want to proceed), to NASA mission managers (worried about delays and costs associated with planetary protections surprises.)

    And then there’s the general public which might (or might not) have entirely different ethical concerns about the potential for contaminating other planets and moons with Earth life.

    No wonder the problem is deemed wicked.

    We’ll get into the pros and cons, but first some background:

    I asked NASA’s Planetary Protection officer, Catharine Conley, whether Earth life has been transported to its most likely solar system destination, Mars.

    3
    Catharine “Cassie” Conley has been NASA’s Planetary Protection officer since 2006. There is only one other full-time official in the world with the same responsibilities, and he works for the European Space Agency. (NASA/W. Hrybyk)

    Her reply: “There are definitely Earth organisms that we’ve brought to Mars and are still alive on the spacecraft.”

    NASA/Mars Curiosity Rover

    She said it is quite possible that some of those organisms were brushed off the vehicles or otherwise were shed and fell to the surface. Because of the strong ultraviolet radiation and the Earth life-destroying chemical makeup of the soil, however, it’s unlikely the organisms could last for long, and equally unlikely that any would have made it below the surface. Nonetheless, it is sobering to hear that Earth life has already made it to Mars.

    Related to this reality is the understanding that Earth life, in the form of bacteria, algae and fungi and their spores, can be extraordinarily resilient. Organisms have been discovered that can survive unimagined extremes of heat and cold, can withstand radiation that would kill us, and can survive as dormant spores for tens of thousands of years.

    What’s more, Mars scientists now know that the planet was once much warmer and wetter, and that ice underlies substantial portions of the planet. There are even signs today of seasonal runs of what some scientists argue is very briny surface water.

    So the risk of Earth life surviving a ride to another planet or moon is probably greater than imagined earlier, and the possibility of that Earth life potentially surviving and spreading on a distant surface (think the oceans of Europa and Enceladus, or maybe a briny, moist hideaway on Mars) is arguably greater too. From a planetary protection perspective, all of this is worrisome.

    The logic of planetary protection is, like almost everything involved with the subject, based on probabilities. Discussed as far back as the 1950s and formalized in the 1967 Outer Space Treaty, the standard agreed on is to take steps that ensure there is less than a 1 in 10,000 chance of a spaceship or lander or instrument from Earth bringing life to another body.

    This figure takes into account the number of microorganisms on the spacecraft, the probability of growth on the planet or moon where the mission is headed, and a series of potential sanitizing to sterilizing procedures that can be used. A formula for assessing the risk of a mission for planetary protection purposes was worked out in 1965 by Carl Sagan, along with Harvard theoretical physicist Sidney Coleman.

    4
    Deinococcus radiodurans is an extremophilic bacterium, one of the most radiation-resistant organisms known. It can survive cold, dehydration, vacuum, and acid, and is therefore known as a polyextremophile and is considered perhaps the world’s toughest bacterium. It can withstand a radiation dose 1,000 times stronger than what would kill a person. No image credit.

    A lot has been learned since that time, and some in the field say it’s time to re-address the basics of planetary protection. They argue, for instance, that since we now know that Earth life can (theoretically, at least) be carried inside a meteorite from our planet to Mars, then Earth life may have long been on Mars — if it is robust enough to survive when it lands.

    In addition, a great deal more is known about how to sanitize a space vehicle without baking it entirely — a step that is both very costly and could prove deadly to the more sophisticated capsules and instruments. And more is known about the punishing environment on the surface of Mars and elsewhere.

    People ranging from Mars Society founder Robert Zubrin to Cornell University Visiting Scientist Alberto G. Fairén in Nature Geoscience have argued — and sometimes railed — against planetary protection requirements. NASA mission managers have often voiced their concerns as well. The regulations, some say, slow the pace of exploration and science to avoid a vanishingly small risk.

    5
    Brent Sherwood, planetary mission formulation manager for JPL, is currently overseeing two proposed projects for New Frontiers missions. One is to search for signs of life on Saturn’s moon Enceladus and the other for habitability on the moon Titan. (Brent Sherwood)

    Brent Sherwood, program manager for solar system mission formulation at JPL, spoke at AbSciCon about what he sees as the need for a review and possibly reassessment of the planetary protection rules and regulations. As someone who helps scientists put together proposals for NASA missions in the solar system, he has practical and long considered views about planetary protection.

    He and his co-authors argue that the broad conversation that needs to take place should include scientists, ethicists, managers, and policy makers; and especially should include the generations that will actually implement and live with the consequences of these missions.

    In the abstract for his talk, Sherwood wrote:

    “The (1 chance in 10,000) requirement may not be as logically sound or deserving of perpetuation as generally assumed. What status should this requirement have within an ethical decision-making process? Do we need a meta-ethical discussion about absolute values, rather than an arbitrary number that purports to govern the absolute necessity of preserving scientific discovery or protecting alien life?”
    As he later he told me: “I’m recommending that we be proactive and engage the broadest possible range of stakeholder communities…. With these big, hairy risk problems, everything is probabilistic and open to argument. People are bad at thinking of very small and very big numbers, and the same for risks. They tend to substitute opinion for fact.”
    Sherwood is no foe of planetary protection. But he said planetary protection is a “foundational” part of the space program, and he wants to make sure it is properly adapted for the new space era we are entering.”

    6
    Elon Musk of SpaceX, Jeff Bezos of Blue Origins and NASA have all talked about potentially sending astronauts to Mars or establishing a colony on Mars in the decades ahead. Many obstacles remain, but planning is underway. (Bryan Versteeg/Spacehabs.com)

    Planetary protection officer Conley contends that regular reviews are already built into the system. She told me that every mission gets a thorough planetary protection assessment early in the process, and that there is no one-size-fits-all approach. Rather, the risks and architecture of the missions are studied within the context of the prevailing rules.

    In addition, she said, the group that oversees planetary protection internationally — the Committee on Space Research (COSPAR) — meets every two years and its Panel on Planetary Protection takes up general topics and welcomes input from whomever might want to raise issues large or small.

    “You hear it said that there are protected areas on Mars or Europa where missions can’t go, but that’s not the case,” she said. “These are sensitive areas where life just might be present now or was present in the past. If that’s the case, then the capsule or lander or rover has to be sterilized to the level of the Viking missions.”

    She said that she understood that today’s spacecraft are different from Viking, which was designed and built from scratch with planetary protection in mind. Today, JPL and other mission builders get some of their parts “off the shelf” in an effort to make space exploration less expensive.

    “We do have to balance the goals of exploration and space science with making sure that Earth life does not take hold. We also have to be aware that taxpayer money is being spent. But if a mission sent out returns a signal of life, what have we achieved if it turns out to be life we brought there?

    “I see planetary protection as a great success story. People identified a potential contamination problem back in the 50s, put regulations into place, and have succeeded in avoiding the problem. This kind of global cooperation that leads to the preventing of a potentially major problem just doesn’t happen that often.

    The global cooperation has been robust, Conley said, despite the fact that only NASA and the European Space Agency have a full-time planetary protection officer.

    She cited the planning for the joint Russian-Chinese mission to the Martian moon Phobos as an example of other nations agreeing to very high standards. She and her European Space Agency (ESA) counterpart traveled twice to Moscow to discuss planetary protection steps being taken.

    7
    Andrew Maynard is the director of Arizona State University’s Risk Innovation Lab and is a professor in School for the Future of Innovation in Society. (ASU.)

    So far, she said private space companies have been attentive to planetary protection as well. Some of the commercial space activity in the future involve efforts to mine on asteroids, and Conley said there is no planetary protection issues involved. The same with mining on our moon.

    But should the day arrive that private companies such as SpaceX and Blue Origin seriously propose a human mission to Mars — as they have said they plan to — Conley said they would have the same obligations as for NASA mission. The US has not yet determined how to ensure that compliance, she said, but companies already would need Federal Aviation Administration approval for a launch, and planetary protection is part of that.

    Risk innovation expert Maynard, however, was not so sure about those protections. He said he could imagine a situation where Elon Musk of SpaceX or Jeff Bezos of Blue Origin or any other space entrepreneur around the world would decide to move their launch to a nation that would be willing to provide the service without intensive planetary protection oversight.

    “The risk of this may be small, but this is all about the potentially outsize consequences of small risks,” he said.

    Maynard said that was hardly a likely scenario — and that commercial space pioneers so far have been supportive of planetary protection guidelines — but that he was well aware of the displeasure among some mission managers and participating scientists about planetary protection requirements.

    Given all this, it’s easy to see how and why planetary protection advocates might feel that the floodgates are being tested, and why space explorers looking forward to a time when Mars and other bodies might be visited by astronauts and later potentially colonized are concerned about potential obstacles to their visions.

    8
    An artist’s rendering of a sample return from Mars. Both the 2020 NASA Mars mission and the ESA-Russian mission are designed to identify and cache intriguing rocks for delivery to Earth in the years ahead. (Wickman Spacecraft & Propulsion)

    This column has addressed the issue of “forward contamination” — how to prevent Earth life from being carried to another potentially habitable solar system body and surviving there. But there is another planetary protection worry and that involves “backward contamination” — how to handle the return of potentially living extraterrestrial organisms to Earth.

    That will be the subject of a later column, but suffice it to say it is very much on the global space agenda, too.

    The Apollo astronauts famously brought back pounds of moon rocks, and grains of asteroid and comet dust have also been retrieved and delivered. A sample return mission by the Russian and Chinese space agencies was designed to return rock or grain samples from the Martian moon Phobos earlier this decade, but the spacecraft did not make it beyond low Earth orbit.

    However, the future will see many more sample return attempts. The Japanese space agency JAXA launched a mission to the asteroid 162173 Ryugu in 2014 (Hayabusa 2) and it will arrive there next year.

    JAXA/Hayabusa 2

    The plan is collect rock and dust samples and bring them back to Earth. NASA’s OSIRIS-REx is also making its way to an asteroid, 101955 Bennu, with the goal of collecting a sample as well for return to Earth.

    NASA OSIRIS-REx Spacecraft

    And in 2020 both NASA and ESA (with Russian collaboration) will launch spacecraft for Mars with the intention of preparing for future sample returns. Sample return is a very high priority in the Mars and space science communities, and many consider it essential for determining whether there has ever been life on Mars.

    So the “wicked” challenges of planetary protection are only going to mount in the years ahead.

    See the full article here .

    Please help promote STEM in your local schools.

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 4:08 pm on May 8, 2017 Permalink | Reply
    Tags: , , , , Many Worlds, , ,   

    From Many Worlds: “Supernovae Give, And Can Take Away” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-05-08
    Marc Kaufman

    1
    What is likely the brightest supernova in recorded human history, SN 1006 lit up planet Earth’s sky in the year 1006 AD. The expanding debris cloud from the stellar explosion, still puts on a cosmic light show across the electromagnetic spectrum. The supernova is located about 7,000 light-years from Earth, meaning that its thermonuclear explosion actually happened 7,000 years before the Earth. Shockwaves in the remnant accelerate particles to extreme energies and are thought to be a source of the mysterious cosmic rays. NASA, ESA, Zolt Levay (STScI)

    We live in a dangerous universe. We know about meteor and comets, about harmful radiation that could extinguish life without an electromagnetic shield, about major changes in climate that are both natural and man-made.

    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase

    There’s another risk out there that some scientists assert could cause large-scale extinctions even though it would occur scores of light-years away. These are supernovae – explosions of massive stars that both create and spread the heavy elements needed for life and send out high energy cosmic rays that can travel far and cause enormous damage.

    6
    http://hyperphysics.phy-astr.gsu.edu/hbase/Astro/snovcn.html

    As with most of these potential threats, they fortunately occur on geological or astronomical time scales rather than human ones. But that doesn’t mean they don’t happen.

    At the recent Astrobiology Science Conference (AbSciCon) a series of talks focused on that last threat – starting with a talk on “When Stars Attack.”

    And together five different presenters made a persuasive case that Earth was on the receiving end of a distant supernova explosion some two to three million years ago, and probably around 7 or 8 million years ago as well. The effects of the cosmic ray bombardment have been debated and disputed, but the evidence for the occurrences is based on the rock record and is now strong.

    “The evidence is there on the ocean floor, in rocks, nodules and sediment,” said Brian Fields, professor of astronomy at University of Illinois. “We’ve been able to date it and provide some idea of how far away the star blew up.” The answer is between about 90 and 300 light-years.

    2
    Supernova 1994D exploded on the outskirts of disk galaxy, and outshines even the center of the galaxy. Supernovae may expel much, if not all, of the material away from a star, at velocities up to 30,000 km/s or 10% of the speed of light. This drives an expanding and fast-moving shock wave into the surrounding interstellar medium that, if close to Earth (or any other planet) can have dire consequences. Supernovae also create, fuse and eject the bulk of the chemical elements produced by nucleosynthesis, the heavier elements needed to form planets and later make possible life. ( High-Z Supernova Search Team, HST, NASA)

    “Supernova explosions happen all the time– on average every 30 years in our galaxy, though they are most often obscured from view,” Fields said. “They generate cosmic rays that can spread through the galaxy for 100 million years. These are the cosmic rays that make carbon-14 and can threaten astronauts in space. But that’s not what we’re focused on — we look at the ones that are close to us and could have a far more dramatic effect, and they are pretty rare.”

    HESS Cherenko Array, searching for cosmic rays, located on the Cranz family farm, Göllschau, in Namibia, near the Gamsberg

    What is deemed to be the “kill zone” for a planet nearby a supernova is 30 light-years; the high energy particles from an explosion that close would, he said, likely end all or most life on Earth by setting into motion a variety of atmospheric and surface changes. Fields there is no evidence of such a close and damaging supernove within the past 10 million years, the period that has been studied with some rigor.

    But because a close supernova explosion hasn’t happened recently doesn’t mean that it didn’t happened during earlier times. Or that it couldn’t happen in the far future.

    “By nailing the signal of a close but not ‘kill zone’ supernova two to three million years ago, and most likely another at 7 to 8 million years ago, we make the case that supernova can and do have significant effects on Earth.”

    The community of scientists who study supernovae and their effects on Earth, both potential and known, is small, and has been most active in the past decade. There was an earlier time when scientists focused on supernovae as the potential cause for the massive dinosaur extinction, but the field shrank with confirmation in 1990 that a six-mile wide meteor landed on Mexico’s Yucatan Peninsula about million years ago and was the likely cause of the global extinction.

    But now, with the advent of new theories and some very high tech and precise measuring the field and subject has come to life, with research nodes in Germany, Australia and the American Midwest.

    The key to understanding the effects of distant supernovae on Earth involves a radioactive isotope of iron, iron-60.

    7
    Nailing the half-life of iron-60, http://physicsworld.com/cws/article/news/2015/jan/30/nailing-the-half-life-of-iron-60

    It’s one of the many elements known to be sent into the cosmos by the massive thermonuclear blasts that define a supernova, that send out shock waves capable of spurring the formation of new stars as well as providing the universe with the heavier chemical elements needed to form everything from planets to genes.

    It was the young Fields and colleagues who theorized some two decades ago that iron-60 could be a telltale sign of a relatively nearby supernova. He told me that no other sources of iron 60 are known to exist, and so if it were found on Earth scientists would know where it came from.

    With a half-life of some three million years, the iron-60 would be a potentially strong signal for that length of time and and then a weaker but potentially detectable signal after that.

    The question was how do you find iron-60 on Earth? The answer came from the bottom of the ocean.

    First in 1999 a group from the Technical University of Munich [TUM] in Germany identified some iron-60 in iron-manganese crustal rocks at the bottom of the Pacific, and then last year an overlapping group from the Technical University of Berlin reported finding the telltale isotope in not only rocks but also in nodules and most important in sea-floor sediments. They used ultra-sensitive accelerator mass spectrometry to isolate and identify the iron-60, which they reported was deposited some 1.6 to 3 million years ago.

    9
    Accelerator mass spectrometer at Lawrence Livermore National Laboratory
    “The 1 MV accelerator mass spectrometer was (see photo) developed partially under the Resource funding. 14C and tritium analyses of biomedical samples submitted by Resource users are conducted using this 1 MV system. The AMS spectrometer consists of a cesium sputter source, low-energy injection beam line, the high voltage collision cell (accelerator), a high-energy mass spectrometer and a particle detector for energy measurements (proceeding clockwise from lower left in the photograph).”
    Source http://bioams.llnl.gov/equipment.php

    3
    These are transmission electron microscope images showing tiny magnetofossils containing iron-60, a form of iron produced during the violent explosion and death of a massive star in a supernova. They were deposited by bacteria in sediments found on the floor of the Pacific Ocean.© Marianne Hanzlik, Chemie Department, FG Elektronenmikroskopie, Technische Universität München

    Last year as well the Australian group, led by Anton Wallner of the Australian National University, found the iron-60 to be deposited globally and to have arrived within the same general time frame. And Gunther Korschinek, a physicist at the Technical University of Munich involved in the initial German iron-60 detections, led a team that found elevated amounts of iron-60 in moon rocks returned to Earth during the Apollo program.

    As Fields put it, the studies together gave a clear signal of a supernova explosion, or series of explosions, at 2 to 3 million years ago, and a less clear but likely signal of the same at 7 to 8 million years ago.

    Since Fields and other scientists were presenting during the AbSciCon conference, the talks not surprisingly focused on potential biological implications of supernova explosions. And while supernova impacts on the biosphere are not particularly well understood, a number of intriguing theories were presented.

    Brian Thomas of Washburn University described how cosmic rays from close supernova would significantly increase levels of electrically charged elements and molecules in the atmosphere, lasting thousands of years. In the upper atmosphere this would have the effect of setting into motion a chemical cascade that would deplete stratospheric ozone. In the lower atmosphere, the effect would likely be changes in climate and minor mass extinctions.

    The “holy grail” of their supernova work is matching a detected one with a dramatic event in the Earth biosphere, most especially a mass extinction. The 2 to 3 million years ago period includes the boundary between the Pleistocene and Pliocene epochs, when Earth climate changed and major glaciations periods began — possibly supernova-related changes but not the extreme change a close supernova could produce.

    Another potential effect of the supernova event of 2 to 3 million years ago is increased rates of mutation and of lightning, and thus forest fires on Earth.

    Adrian Merlott of the University of Kansas suggested that expected mutations from radiation sources such as supernovae could explain evolutionary changes in a variety of groups of organisms and creatures during that period — as a result of increased deadly cancers in some species and increased positive mutations in others.

    He also said that evidence of more widespread wildfires during that long period — as measured in charcoal deposits — could be the result of increased cloud to ground lightning induced by the additional high-energy particle environment created by a relatively close supernova explosion.

    4
    The Crab nebula – one of the most glorious images produced by the Hubble Space Telescope — is the remnant of supernovae explosions that occurred at a distance of some 6,700 light-years. The very bright light of the explosion was noted in 1054 and remained visible for around two years. The event was recorded in contemporary Chinese astronomy, and references to it are also found in a later (13th-century) Japanese document, perhaps in pictograph associated with the Anasazi people of the Southwest. The supernova, SN 1054 has been widely studied and is often considered the best known supernova in astronomy. (NASA).

    The iron-60 signatures of a close supernova have been a great boon to the field, but they do not go back beyond that almost 10 million year period when the radioactivity was present. To go back further than that, Fields said different radioactive signatures would be needed — and not those that go back to the formation of the planet.

    “It’s a hard problem because nature has been unkind,” he said. “The early mass extinctions – 100 million and more years ago – need radioactivity that lasts that long. And the only element we’ve found is plutonium-244, which is not stable in any form.”

    9
    http://www.alamy.com/stock-photo/plutonium-244.html

    Plutonium-244 has a half life of 80 million years, and so could potentially be used to identify close supernova explosions in a manner similar to iron-60, but during that much longer time frame. And as Fields explained it, plutonium-244 is produced in only two ways: during the explosion of a nuclear bomb or the explosion of a supernovae.

    Although the science around the formation and detection of plutonium-244 in nature is immature, he said it remains the best pathway to find that “holy grail” — a known mass extinction directly associated with a close supernova explosion.

    5
    Supernovae can burn with a luminosity of ten billion suns. This show a before and after for supernova 1987A, which exploded in 1987 in the Large Magellanic Cloud (LMC), a nearby galaxy. (Australian Astronomical Observatory/ David Malin)

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 7:21 am on April 24, 2017 Permalink | Reply
    Tags: , , , Many Worlds, , Natalie Batalha,   

    From Many Worlds: Women in STEM – “The Influential Natalie Batalha” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-04-24
    Marc Kaufman

    1
    Natalie Batalha, project scientist for the Kepler mission and a leader of NASA’s NExSS initiative on exoplanets, was just selected as one of Time Magazine’s 100 most influential people in the world. (NASA, TIME Magazine.)

    I’d like to make a slight detour and talk not about the science of exoplanets and astrobiology, but rather a particular exoplanet scientist who I’ve had the pleasure to work with.

    The scientist is Natalie Batalha, who has been lead scientist for NASA’s landmark Kepler Space Telescope mission since soon after it launched in 2009, has serves on numerous top NASA panels and boards, and who is one of the scientists who guides the direction of this Many Worlds column.

    Last week, Batalha was named by TIME Magazine as one of the 100 most influential people in the world. This is a subjective (non-scientific) calculation for sure, but it nonetheless seems credible to me and to doubtless many others.

    Batalha and the Kepler team have identified more than 2500 exoplanets in one small section of the distant sky, with several thousand more candidates awaiting confirmation. Their work has once and for all nailed the fact that there are billions and billions of exoplanets out there.

    “NASA is incredibly proud of Natalie,” said Paul Hertz, astrophysics division director at NASA headquarters, after the Time selection was announced.

    “Her leadership on the Kepler mission and the study of exoplanets is helping to shape the quest to discover habitable exoplanets and search for life beyond the solar system. It’s wonderful to see her recognized for the influence she has had on the world – and on the way we see ourselves in the universe.”

    And William Borucki, who had the initial idea for the Kepler mission and worked for decades to get it approved and then to manage it, had this to say about Batalha:

    “She has made major contributions to the Kepler Mission throughout its development and operation. Natalie’s collaborative leadership style, and expert knowledge of the population of exoplanets in the galaxy, will provide guidance for the development of successor missions that will tell us more about the habitability of the planets orbiting nearby stars.”

    1
    Batalha has led the science mission of the Kepler Space Telescope since it launched in 2009. (NASA)

    As a sign of the perceived importance of exoplanet research, two of the other TIME influential 100 are discoverers of specific new worlds. They are Guillem Anglada-Escudé (who led a team that detected a planet orbiting Proxima Centauri) and Michael Gillon (whose team identified the potentially habitable planets around the Trappist-1 system.)

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets, NASA announced on Wednesday. (NASA)

    ESO Belgian robotic Trappist National Telescope at Cerro La Silla, Chile interior

    But Batalha, and no doubt the other two scientists, stress that they are part of a team and that the work they do is inherently collaborative. It absolutely requires that many others also do difficult jobs well.

    For Batalha, working in that kind of environment is a natural fit with her personality and skills. Having watched her at work many times, I can attest to her ability to be a strong leader with extremely high standards, while also being a kind of force for calm and inclusiveness.

    We worked together quite a bit on the establishing and running of this column, which is part of the NASA Nexus for Exoplanet System Science (NExSS) initiative to encourage interdisciplinary thinking and collaboration in exoplanet science.

    It was NASA’s astrobiology senior scientist Mary Voytek who set up the initiative and saw fit to start this column, and it was Batalha (along with several others) who helped guide and focus it in its early days.

    I think back to her patience. I was visiting her at NASA’s Ames Research Center in Silicon Valley and talking shop — meaning stars and planets and atmospheres and the like. While I had done a lot of science reporting by that time, astronomy was not a strong point (yet.)

    So in conversation she made a reference to stars on the Hertzsprung-Russell diagram and I must have had a somewhat blank look to me. She asked if I was familiar with Hertzsprung-Russell and I had to confess that I was not.

    Not missing a beat, she then went into an explanation of what is a basic feature of astronomy, and did it without a hint of impatience. She just wanted me to know what the diagram was and what it meant, and pushed ahead with good cheer to bring me up to speed — as I’m sure she has done many other times with many people of different levels of exposure to the logic and complexities of her very complex work.

    4
    Hertzsprung–Russell diagram with 22,000 stars plotted from the Hipparcos Catalogue and 1,000 from the Gliese Catalogue of nearby stars. Stars tend to fall only into certain regions of the diagram. The most prominent is the diagonal, going from the upper-left (hot and bright) to the lower-right (cooler and less bright), called the main sequence. In the lower-left is where white dwarfs are found, and above the main sequence are the subgiants, giants and supergiants. The Sun is found on the main sequence at luminosity 1 (absolute magnitude 4.8) and B−V color index 0.66 (temperature 5780 K, spectral type G2V). Wikipedia

    (Incidently, the Hertzsprung-Russell diagram plots each star on a graph measuring the star’s brightness against its temperature or color.)

    I mention this because part of Batalha’s influence has to do with her ability to communicate with individuals and audiences from the lay to the most scientifically sophisticated. Not surprisingly, she is often invited to be a speaker and I recommend catching her at the podium if you can.

    3
    By chance — or was it chance? — the three exoplanet scientists selected for the Time 100 were at Yuri Milner’s Breakthrough Discuss session Thursday when the news came out. On the left is Anglada-Escude, Batalha in the middle and Gillon on the right.

    Batalha was born in Northern California with absolutely no intention of being a scientist. Her idea of a scientist, in fact, was a guy in a white lab coat pouring chemicals into a beaker.

    As a young woman, she was an undergrad at the University of California at Berkeley and planned on going into business. But she had always been very good and advanced in math, and so she toyed with other paths. Then, one day, astronaut Rhea Setton came to her sorority. Setton had been a member of the same sorority and came to deliver a sorority pin she had taken up with during on a flight on the Space Shuttle.

    “That visit changed my path,” Batalha told me. “When I had that opportunity to see a woman astronaut, to see that working for NASA was a possibility, I decided to switch my major — from business to physics.”

    After getting her BA in physics from UC Berkeley, she continued in the field and earned a PhD in astrophysics from UC Santa Cruz. Batalha started her career as a stellar spectroscopist studying young, sun-like stars. Her studies took her to Brazil, Chile and, in 1995, Italy, where she was present at the scientific conference when the world learned of the first planet orbiting another star like our sun — 51 Pegasi b.

    It had quite an impact. Four years later, after a discussion with Kepler principal investigator Borucki at Ames about challenges that star spots present in distinguishing signals from transiting planets, she was hired to join the Kepler team. She has been working on the Kepler mission ever since.

    Asked how she would like to use her now publicly acknowledged “influence,” she returned to her work on the search for habitable planets, and potentially life, beyond earth.

    “We’ve seen that there’s such a keen public interest and an enormous scientific interest in terms of habitable worlds, and we have to keep that going,” she said. “This is a very hard problem to solve, and we need all hands on deck.”

    She said the effort has to be interdisciplinary and international to succeed, and she pointed to the two other time 100 exoplanet hunters selected. One is from Belgium and the other is working in the United Kingdom, but comes from Spain.

    When the nominal Kepler mission formally winds down in September, she says she looks forward to more actively engaging with the exoplanet science Kepler has made possible.

    4
    The small planets identified by Kepler as of one year ago that are small and orbit in the region around their star where water can exist as a liquid. NASA Ames/N. Batalha and W. Stenzel

    Batalha’s role in the NASA NExSS initiative offers a window into what makes her a leader — she excels at making things happen.

    Voytek and Shawn Domogal-Goldman of Goddard founded and oversee the group. They then chose Batalha two other leaders (Anthony Del Genio of the Goddard Institute for Space Studies and Dawn Gelino of NASA Exoplanet Science Institute ) to be the hands-on leaders of the 18 groups of scientists from a wide variety of American universities.

    (Asked why she selected Batalha, Voytek replied, “TIME is recognizing what motivated us to select her as one of the leaders for….NExSS. Her scientific and leadership excellence.”)

    This is the official NExSS task: “Teams will help classify the diversity of worlds being discovered, understand the potential habitability of these worlds, and develop tools and technologies needed in the search for life beyond Earth. Scientists are developing ways to identify habitable environments on these worlds and search for biosignatures, or signs of life. Central to the work of NExSS is understanding how biology interacts with the atmosphere, surface, oceans, and interior of a planet, and how these interactions are affected by the host star.”

    She has encouraged and helped create the kinds of collaborations that these tasks have made essential, but also helped identify upcoming problems and opportunities for exoplanet research and has started working on ways to address them. For instance, it became clear within the NExSS group and larger community that many, if not most exoplanet researchers would not be able to effectively apply for time to use the James Webb Space Telescope (JWST) for several years after it launched in late 2018.

    NASA/ESA/CSA Webb Telescope annotated

    To be awarded time on the telescope, researchers have to write detailed descriptions of what they plan to do and how they will do it. But how the giant telescope will operate in space is not entirely know — especially as relates to exoplanets. So it will be impossible for most researchers to make proposals and win time until JWST is already in space for at least two of its five years of operation.

    Led by Batalha, exoplanet scientists are now hashing out a short list of JWST targets that the community as a whole can agree should be the top priorities scientifically and to allow researchers to learn better how JWST works. As a result, they would be able to propose their own targets for research much more quickly in those early years of JWST operations. It’s the kind of community consensus building that Batalha is known for.

    She also has an important roles in the NASA Astrophysics Advisory Committee and hopes to use the skills she developed working with Kepler on the upcoming Transiting Exoplanet Survey Satellite (TESS) mission.

    NASA/TESS

    5
    Batalha preparing for the Science Walk in San Francisco on Earth Day.

    A mother of four (including daughter Natasha, who is on her way to also becoming an accomplished astrophysicist), Batalha is active on Facebook sharing her activities, her often poetic thoughts, and her strong views about scientific and other issues of the day.

    She was an active participant, for instance, in the National March for Science in San Francisco, posting photos and impressions along the way. I think it’s fair to say her presence was noticed with appreciation by others.

    And that returns us to what she considers to be some of her greatest potential “influence” — being an accomplished, high ranking and high profile NASA female scientist.

    “I don’t have to stand up and say to young women ‘You can do this.’ You can just exist doing your work and you become a role model. Like Rhea Setton did with me.”

    And it is probably no coincidence that four other senior (and demanding) positions on the Kepler mission are filled by women — two of whom were students in classes taught some years ago by Natalie Batalha.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 11:23 am on April 21, 2017 Permalink | Reply
    Tags: , , , , Many Worlds,   

    From Many Worlds: “NASA Panel Supports Life-Detecting Lander for Europa; Updated” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-04-20
    Marc Kaufman

    1
    Artist conception of water vapor plumes coming from beneath the thick ice of Jupiter’s moon Europa. The plumes have not been definitively detected, but Hubble Space Telescope images made public earlier this month appear to show plume activity in an area where it was detected once before. How will this finding affect decision-making about a potential NASA Europa lander mission? (NASA)

    As I prepare for the Astrobiology Science Conference (Abscicon) next week in Arizona, I’m struck by how many speakers will be discussing Europa missions, Europa science, ocean worlds and habitability under ice. NASA’s Europa Clipper mission to orbit that moon, scheduled for launch to the Jupiter system in the mid 2020s, explains part of the interest, but so too does the unsettled fate of the Europa lander concept.

    NASA Europa Clipper

    The NASA Science Definition Team that studied the Europa lander project will both give a science talk at the conference and hold an afternoon-long science community meeting on their conclusions. The team argued that landing on Europa holds enormous scientific promise, most especially in the search for life beyond Earth.

    But since the Europa lander SDT wrote its report and took its conclusions public early this year, the landscape has changed substantially. First, in March, the Trump Administration 2018 budget eliminated funding for the lander project. More than half a billion dollars have been spent on Europa lander research and development, but the full project was considered to be too expensive by the White House.

    Administration budget proposals and what ultimately become budget reality can be quite different, and as soon as the Europa lander was cancelled supporters in Congress pushed back. Rep. John Culberson (R-Tex.) and chair of the House subcommittee that oversees the NASA budget, replied to the proposed cancellation by saying “NASA is a strategic national asset and I have no doubt NASA will receive sufficient funding to complete the most important missions identified by the science community, including seeking out life in the oceans of Europa.”

    More recently, researchers announced additional detections of plumes of water vapor apparently coming out of Europa — plumes in the same location as a previous apparent detection. The observing team said they were confident the difficult observation was indeed water vapor, but remained less than 100 percent certain. (Unlike for the detection of a water plume on Saturn’s moon Enceladeus, which the Cassini spacecraft photographed, measured and flew through.)

    So while suffering a serious blow in the budgeting process, the case for a Europa lander has gotten considerably stronger from a science and logistics perspective. Assuming that the plume detections are accurate, a lander touching down in that general area would potentially have some access to surface H20 that was in the vast global ocean under the ice not too long ago.

    Science fiction writer and proto-astrobiologist Arthur C. Clarke famously wrote decades ago that the first life found beyond Earth would most likely be in the oceans of Europa. In the early 1980s he wrote a sequel to “2001: A Space Odyssey” called “2010: Odyssey Two”, with life under the ice of Europa central to the plot.

    At the climactic moment in the novel, the hero returns to the iconic computer HAL which sends out this message:

    ALL THESE WORLDS ARE YOURS – EXCEPT EUROPA.
    ATTEMPT NO LANDINGS THERE.

    Hopefully Congress and the White House, if not HAL, can be persuaded otherwise.

    Here is a column I wrote about the Europa lander SDT in February:

    2
    Artist rendering of a potential life-detecting lander mission to Europa that would follow on the Europa Clipper orbiter mission. In the background is Jupiter. NASA/JPL/Caltech

    It has been four long decades since NASA has sent an officially-designated life detection mission into space. The confused results of the Viking missions to Mars in the mid 1970s were so controversial and contradictory that scientists — or the agency at least — concluded that the knowledge needed to convincingly search for extraterrestrial life wasn’t available yet.

    But now, a panel of scientists and engineers brought together by NASA has studied a proposal to send a lander to Jupiter’s moon Europa and, among other tasks, return to the effort of life-detection.

    In their recommendation, in fact, the NASA-appointed Science Definition Team said that the primary goal of the mission would be “to search for evidence of life on Europa.”

    The other goals are to assess the habitability of Europa by directly analyzing material from the surface, and to characterize the surface and subsurface to support future robotic exploration of Europa and its ocean.

    Scientists agree that the evidence is quite strong that Europa, which is slightly smaller than Earth’s moon, has a global saltwater ocean beneath its deep ice crust, and that it contains twice as much water as exists on Earth.

    For the ocean to be liquid there must be substantial sources of heat — from tidal heating based on the shape of its orbits, or from heat emanating from radioactive decay and entering the ocean through hydrothermal vents. All could potentially provide an environment where life could emerge and survive.

    Kevin Hand of the Jet Propulsion Laboratory is a specialist in icy worlds and is deputy project scientist for the Europa project. He was one of the co-chairs of the Science Definition Team (SDT) and he said the group was ever mindful of the complicated history of the Viking missions. He said that some people called Viking a “failure” because it did not clearly identify life, but he described that view as “entirely unscientific.”

    “It would be misguided to set out to ‘find life’,” he told me. “The real objective is to test an hypothesis – one we have that if you bring together the conditions for life as we know them, then they might come together and life can inhabit the environment.

    “As far as we can tell, Europa has the water, the elements and the energy needed to create a habitable world. If the origin of life involves some relatively easy processes, then it just might be there on Europa.”

    4
    This artist’s rendering shows NASA’s Europa orbiter mission spacecraft, which is being developed for a launch sometime in the 2020s. The mission would place a spacecraft in orbit around Jupiter in order to perform a detailed investigation of the planet’s moon Europa. The spacecraft will arrive at Jupiter after a multi-year journey, orbiting the gas giant every two weeks for a series of 45 flybys of Europa. NASA generally sends orbiters to a planet or moon before sending a lander. (NASA)

    The conclusions of the SDT team, which is made is up of dozens of scientists and engineers, will set the stage for further review, rather than for immediate action. The report goes to NASA, where it is assessed in relation to other compelling and competing missions. Both the Congress and White House can and do weigh in

    If it is approved, the Europa lander mission would be a companion to the already funded Europa multiple flyby mission scheduled to launch in the 2020s. While that spacecraft, the Europa Clipper, would have some capacity to determine whether or not the icy moon is habitable, a lander would be needed to search for actual signs of life.

    A mission to Europa was a top priority of the 2010 Decadal Review, a synthesis of potential projects in various disciplines that is reviewed by the National Research Council of the National Academy of Sciences.

    Its recommendations from the Decadal Review are generally followed by NASA. It remains unclear whether the Europa lander is a natural follow-on to the Europa Clipper or a new initiative to be judged on its own. But the project does have strong support — last year Rep. John Culberson (R-Tex.) pushed a bill through Congress making it illegal to not send a lander to Europa.

    Although there are many hurdles to clear for the Europa lander, the SDT report is nonetheless a rather momentous event since it strongly recommends a life-detection mission. So I thought it was worthwhile to include the entire preface of the team’s conclusions.

    “The Europa Lander Science Definition Team Report presents the integrated results of an intensive science and engineering team effort to develop and optimize a mission concept that would follow the Europa Multiple Flyby Mission and conduct the first in situ search for evidence of life on another world since the Viking spacecraft on Mars in the 1970s.

    The Europa Lander mission would be a pathfinder for characterizing the biological potential of Europa’s ocean through direct study of any chemical, geological, and possibly biological, signatures as expressed on, and just below, the surface of Europa. The search for signs of life on Europa’s surface requires an analytical payload that performs quantitative organic compositional, microscopic, and spectroscopic analysis on five samples acquired from at least 10 cm beneath the surface, with supporting context imaging observations.

    This mission would significantly advance our understanding of Europa as an ocean world, even in the absence of any definitive signs of life, and would provide the foundation for the future robotic exploration of Europa.”

    (Here is the full Europa lander SDT report.)

    Hand said that a lander would be a natural complement to the Europa Clipper, which is being designed to orbit Jupiter and pass by Europa 45 times at altitudes varying from 1675 miles to 16 miles. The flybys, he said, could potentially identify cracks and fissures in the crust of the moon, and thereby help identify where a lander should touch down.

    What’s more, images taken by the Hubble Space Telescope in 2012 suggest that Europa may be spitting out water in plumes that those clearly detected on Saturn’s moon, Enceladus.

    “If a plume was identified during a flyby, you better believe that we would do all we could to land somewhere close to it. The goal is to get as near as possible to the water coming out from under the crust because that’s how we’ll best learn whether that water has complex organic molecules, nitrogen compounds needed for life and possibly life itself.”

    If the lander project does get the green light in the months (or years) ahead, NASA would then put out a call to propose instruments that could search for the various chemical building blocks and manifestations life, as well morphological signs that life once was present. The search for life, in other words, would involve checking the boxes of building blocks or known molecular signs of possible life as they are found (or not found.)

    This is quite a different approach from that used during the Viking missions.

    Famously, the so-called “Labelled Release” experiments on both Viking 1 and Viking 2 met the criteria for having detected life as set out by NASA scientists before the mission began. Those criteria involved the detection of metabolism, the chemical processes that occur within a living organism in order to maintain life. A detection would imply the presence of life right on the harsh, irradiated Martian surface.

    In the LR experiment, a drop of very dilute aqueous nutrient solution was dropped into a sample collected of Martian soil. The nutrients (seven molecules that were products of the Miller-Urey experiment) were tagged with radioactive carbon 14 and the air above the soil was monitored for the evolution of radioactive CO2 gas. The presence of the gas was interpreted as evidence that microorganisms in the soil had metabolized one or more of the nutrients.

    5
    A picture of the Martian surface, as seen by NASA’s Viking 2 lander in 1976.

    The LR was followed with a control experiment, and the results consistently met the criteria for having detected “life.” Two other biology experiments on Viking, however, came up negative, including the one considered most conclusive — that no carbon-based organic material was detected in the soil, except for one interpreted as contamination from Earth.

    Subsequent Mars missions have strongly suggested that those organics interpreted as contamination were, in fact, organics interacting with perchlorate molecules now known to be common on the Martian surface. But despite this revision, the Mars science community remains broadly skeptical of the Labelled Release results, arguing that the CO2 could have been produced without biology. That, however, has not stopped LR principal investigator Gilbert Levin, and some others, from arguing now for forty years that the experiment did find life, creating a controversy that NASA has long struggled with.

    Hand said that in hindsight, “we can see that it didn’t make sense to look for metabolism until we knew a lot more. We need to follow the water, follow the carbon, follow the nitrogen, follow the complex molecules, and if all of that succeeds then we look for a living, breathing creature.”

    One of the inspirations for the hypothesis that Europa might harbor life under and within its ice is the recognition that frozen Antarctica also is home to microbial life. The most significant laboratory is Lake Vostok, an enormous collection of water beneath more than two miles of Antarctic ice.

    Researchers have determined that microbial life exists miles down through the ice. The distribution is small — something like 100 cells per milliliter of melted ice — but researchers have been trying for years to drill down into the lake and determine if the lake itself is home to more abundant life. The research has been done primarily by Russian scientists and engineers, and has been slowed by the harsh conditions and innumerable technical problems.

    6
    Three dimensional model of Lake Vostok drilling. (National Science Foundation)

    But as a proof of concept, Hand said, Lake Vostok and other subglacial lakes in Antarctica show that life can survive in freezing conditions. He said the science teams recommended that any life detection instrument that might go to Europa be able to identify life in the very low concentrations found at Vostok.

    Tori Hoehler, a research scientist at NASA’s Ames Research Center, is a specialist in microbial life in low energy environments (like Vostok and perhaps Europa,) and he is also a member of the Europa lander science definition team.

    “Our present understanding of Europa suggests that it is habitable, but it is more difficult to constrain how abundant or productive a Europan biosphere — should one exist — might be. For that reason, a conservative approach is to look to some of Earth’s most sparsely populated ecosystems when setting measurement targets for the lander.”

    But however low that abundance might be, the detection of anything with characteristics of life on Europa would be a huge advance for science.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 3:36 pm on April 13, 2017 Permalink | Reply
    Tags: , , , , , Many Worlds, Plumes on Enceladus   

    From Many Worlds: “Ocean Worlds: Enceladus Looks Increasingly Habitable, and Europa’s Ocean Under the Ice More Accessible to Sample” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2017-04-13
    Marc Kaufman

    1
    NASA’s Cassini spacecraft completed its deepest-ever dive through the icy plume of Enceladus on Oct. 28, 2015. (NASA/JPL-Caltech)

    It wasn’t that long ago that Enceladus, one of 53 moons of Saturn, was viewed as a kind of ho-hum object of no great importance. It was clearly frozen and situated in a magnetic field maelstrom caused by the giant planet nearby and those saturnine rings.

    That view was significantly modified in 2005 when scientists first detected signs of the icy plumes coming out of the bottom of the planet. What followed was the discovery of warm fractures (the tiger stripes) near the moon’s south pole, numerous flybys and fly-throughs with the spacecraft Cassini, and by 2015 the announcement that the moon had a global ocean under its ice.

    NASA/ESA/ASI Cassini Spacecraft

    Now the Enceladus story has taken another decisive turn with the announcement that measurements taken during Cassini’s final fly-through captured the presence of molecular hydrogen.

    To planetary and Earth scientists, that particular hydrogen presence quite clearly means that the water shooting out from Enceladus is coming from an interaction between water and warmed rock minerals at the bottom of the moon’s ocean– and possibly from within hydrothermal vents.

    These chimney-like hydrothermal vents at the bottom of our oceans — coupled with a chemical mixture of elements and compounds similar to what has been detected in the plumes — are known on Earth as prime breeding grounds for life. One important reason why is that the hydrogen and hydrogen compounds produced in these settings are a source of energy, or food, for microbes.

    A logical conclusion of these findings: the odds that Enceladus harbors forms of simple life have increased significantly.

    To be clear, this is no discovery of extraterrestrial life. But it is an important step in the astrobiological quest to find life beyond Earth.

    “The key here is that Enceladus can produce fuel that could be used by biology,” said Mary Voytek, NASA’s senior scientist for astrobiology, referring to the detection of hydrogen.

    2
    This graphic illustrates how scientists on NASA’s Cassini mission think water interacts with rock at the bottom of the ocean of Saturn’s icy moon Enceladus, producing hydrogen gas (H2). It remains unclear whether the interactions are taking place in hydrothermal vents or more diffusely across the ocean. (NASA)

    “So now on this moon we have many of the components associated with life — water, a source of energy and many of the important chemical building blocks. Nothing coming from Cassini will tell is if there is biology there, but we definitely have found another important piece of evidence of possible habitability.”

    The finding of molecular hydrogen (H2 rather a single hydrogen atom) in the Enceladus plumes was described in a Science paper lead by authors Hunter Waite and Christopher Glein of the Southwest Research Institute, headquartered in San Antonio.

    They went through a number of possible sources of the hydrogen and then concluded that the clearly most likely one was that chemical interaction of cool water and hot rocks — both heated by tidal forces in the complex Saturn system — at the bottom of the global ocean.

    “We previously thought that the water was heated but now we have evidence that the rocks are as well,” Waite told me. “And the evidence suggests that the rock is quite porous, which means that water is seeping through on a large scale and producing these chemical interactions that have a byproduct of hydrogen.”

    4
    The plumes of Enceladus originate in the long tiger stripe fractures of the south polar region pictured here. (Cassini Imaging Team, SSI, JPL, ESA, NASA)

    He said that the process could be taking place in and around those chimney-like hydrothermal vents, or it could be more diffuse across the ocean floor. The vent scenario, he said, was “easier to envision.”

    What’s more, he said, the conditions during this water-rock interaction are favorable for the production of the gas methane, which has been detected in the Enceladus plume.

    This is another tantalizing part of the Enceladus plume story because the earliest lifeforms on Earth are thought to have both consumed and expelled that gas. At this point, however, Waite said there is no way to determine how the methane was formed, which would be a key finding if and when it is made.

    “Our results leave us agnostic on the presence of life,” he said. “We don’t have enough information for that.”

    “But we now can make a strong case that we have a very habitable environment on this moon.” It’s such a strong case, he said, that it would be almost as scientifically interesting to not find life there than to detect it.

    One of the more interesting remaining puzzles is why the hydrogen is present in the plume in such unexpectedly substantial (though initially difficult to detect) amounts. If there was a large microbial community under the ice, then it could plausibly be argued that there wouldn’t be so much hydrogen left if they were consuming it.

    The possibilities: Waite said that it could mean there is just a lot of “food” being produced for potential microbes to survive on in the ocean, or that other factors limit the microbe population size. Or, of course, it could mean that there are no microbes at all to consume the hydrogen food.

    5
    Astronomers have twice found evidence of a plume of water vapor coming from the same location. Both plumes, photographed in UV light by Hubble, were seen in silhouette as the moon passed in front of Jupiter. (NASA/ESA/STScI/USGS)
    [Also shown today in a post from NASA/ESA Hubble]

    News of the Enceladus discovery came on the same day that other researchers announced that strong evidence of detecting a similar plume on Jupiter’s moon Europa using the Hubble Space Telescope.

    This was not the first plume seen on that larger moon of Jupiter, but is perhaps the most important because it appeared to be was spitting out water vapor in the same location as an earlier plume. In other words, it may well be the site of a consistently or frequently appearing geyser.

    “The plumes on Enceladus are associated with hotter regions,” said William Sparks of the Space Telescope Science Institute. “So after Hubble imaged this new plume-like feature on Europa, we looked at that location on the Galileo thermal map. We discovered that Europa’s plume candidate is sitting right on the thermal anomaly,”

    Sparks led the Hubble plume studies in both 2014 and 2016, and their paper was published in The Astrophysical Journal. He said he was quite confident, though not completely confident of the result because of the limits of the Hubble resolution. A 100 percent confirmation, he said, will take more observations.

    Since Europa has long been seen as a strong candidate for harboring extraterrestrial life, this is extraordinarily good news for those hoping to test that hypothesis. Now, rather than devising a way to blast through miles of ice to get to Europa’s large, salty and billions-of-years-old ocean, scientists can potentially learn about the composition of water by studying the plume — as has happened at Enceladus.

    As their paper concluded, “If borne out with future observations, these indications of an active European surface, with potential access to liquid water at depth, bolster the case for Europa’s potential habitability and for future sampling of erupted material by spacecraft.”

    See the full article here .

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    About Many Worlds

    There are many worlds out there waiting to fire your imagination.

    Marc Kaufman is an experienced journalist, having spent three decades at The Washington Post and The Philadelphia Inquirer, and is the author of two books on searching for life and planetary habitability. While the “Many Worlds” column is supported by the Lunar Planetary Institute/USRA and informed by NASA’s NExSS initiative, any opinions expressed are the author’s alone.

    This site is for everyone interested in the burgeoning field of exoplanet detection and research, from the general public to scientists in the field. It will present columns, news stories and in-depth features, as well as the work of guest writers.

    About NExSS

    The Nexus for Exoplanet System Science (NExSS) is a NASA research coordination network dedicated to the study of planetary habitability. The goals of NExSS are to investigate the diversity of exoplanets and to learn how their history, geology, and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context — as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. Leveraging current NASA investments in research and missions, NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy, using a systems science approach.
    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
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