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  • richardmitnick 9:03 am on July 29, 2019 Permalink | Reply
    Tags: "If Bacteria Could Talk", Astrobiology, , Quorum sensing   

    From Many Worlds: “If Bacteria Could Talk” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    July 29, 2019
    Marc Kaufman

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    Hawaiian lava cave microbial mats appear to have the highest levels and diversity of genes related to quorum sensing so far. (Stuart Donachie, University of Hawai`i at Mānoa)

    Did you know that many bacteria — some of the oldest lifeforms on Earth — can talk? Really.

    And not only between the same kind of single-cell bacteria, but back and forth with members of other species, too.

    Okay, they don’t talk in words or with sounds at all. But they definitely communicate in a meaningful and essential way, especially in the microbial mats and biofilms (microbes attached to surfaces surrounded by mucus) that constitute their microbial “cities.”

    Their “words” are conveyed via chemical signaling molecules — a chemical language — going from one organism to another, and are a means to control when genes in the bacterial DNA are turned “on” or “off.” The messages can then be translated into behaviors to protect or enhance the larger (as in often much, much larger) group.

    Called “quorum sensing,” this microbial communication was first identified several decades ago. While the field remains more characterized by questions than definitive answers, is it clearly growing and has attracted attention in medicine, in microbiology and in more abstract computational and robotics work.

    Most recently, it has been put forward as chemically-induced behavior that can help scientists understand how bacteria living in extreme environments on Earth — and potential on Mars — survive and even prosper. And the key finding is that bacteria are most successful when they form communities of microbial mats and biofilms, often with different species of bacteria specializing in particular survival capabilities.

    Speaking at the recent Astrobiology Science Conference in Seattle, Rebecca Prescott, a National Science Foundation Postdoctoral Research Fellow in Biology said this community activity may make populations of bacteria much more hardy than otherwise might be predicted.

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    Quorum sensing requires a community. Isolated Bacteria (and Archaea) have nobody to communicate with and so genes that are activated by quorum sensing are not turned “on.”

    “To help us understand where microbial life may occur on Mars or other planets, past or present, we must understand how microbial communities evolve and function in extreme environments as a group, rather than single species,” said Prescott,

    “Quorum sensing gives us a peek into the interactive world of bacteria and how cooperation may be key to survival in harsh environments,” she said.

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    Rebecca Prescott is a National Science Foundation Postdoctoral Fellow in Biology (1711856) and is working with principal investigator Alan Decho of the University of South Carolina on a NASA Exobiology Program grant.

    And because “quorum sensing” has not been investigated in the world of astrobiology, “this study will be the first to illuminate how microbial interactions might influence survival on Mars and early Earth conditions.”

    This makes quorum sensing of interest to NASA, Prescott told me, because it potentially broadens the universe of environments where bacteria might survive.

    “Microbes don’t function as single species in nature, like we have them in most of our experiments.,” Prescott told me. “It’s therefore important for us to try and understand them as interactive communities – the socialites that they are.”

    Prescott’s research has taken her to extreme environments such as hypersalty ponds with strong ultraviolet light in the Bahamas, the hot springs of Iceland and the lava caves beneath the Hawaiian Islands, to name a few.

    In some of these locales, such as the Bahamas hypersaline mats, it is not unusual for lifeforms to desiccate — a profound drying that few organisms can survive. Yet certain microbes — when enclosed in their protective, slimy biofilms formed with the assistance of quorum sensing — are able go dry for years and then regain activity when water returns.

    Prescott’s colleague and supervisor in the research, University of South Carolina Environmental Health Sciences Professor and Associate Dean for Research Alan Decho, said of these sites: “These are incredibility harsh environments, where very little life other than bacteria can exist.”

    The bacterial samples are now going into a Mars simulator chamber in Scotland. That simulator, in the University of Edinburgh lab of astrobiologist Charles Cockell, will be where the examples of extremophile bacteria are tested for compatibility with an early and then a later Mars atmosphere and to determine how and if their chemical “talking” changes.

    The presence of quorum sensing might also lead some day to the discovery of biosignatures on Mars. This is because the bacteria signaling molecules — acyl homoserine lactones (AHLs) — are neutral lipids, and lipids are often preserved in the rock record.

    5
    Quorum sensing was first identified and proven in the blowfish squid, which lives in sand off the Hawaiian Islands. bioluminescence. (Mattias Ormestad)

    In this tale of “talking bacteria” and their biofilms, it seems only proper that the species most associated with the discovery of quorum sensing by bacteria is the unusual bobtail squid of Hawai`i. The squid develops a striking bioluminescence at night, and it turns out that bacteria in its body are a source of the light.

    The bacteria in the squid (Vibrio fischeri) start the night dark and only become bioluminescent as the density of bacteria grows. That density leads, thanks to the quorum sensing phenomenon, to a changed expression of genes and release of proteins that lead to the bioluminescence. Most of the bacteria are later expelled when daytime comes.

    The tiny squid bacteria and the squid have their own symbiotic relationship: the bacteria collect a sugar and amino acid solution produced by the squid and the bacteria-induced light hides the squid’s silhouette when viewed from below.

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    Prescott and her colleagues collected microbial mats at San Salvador Island of the Bahamas. where a lot of “bacterial talking” occurs. This is a Mars analog site due to high saline and high UV environment.

    For bacteria to use quorum sensing, they must possess three characteristics: the ability to secrete a signaling molecule, the ability to detect a change in concentration of signaling molecules, and an ability to regulate gene expression as a response to that change.

    This process is highly dependent on how the signaling molecules spread. Quorum sensing signaling molecules generally released by individual bacteria in tiny amounts that can slip away undetected if the cell density in the area is low. At high cell densities, the concentration of signaling molecules may exceed its threshold level and trigger changes in gene expressions.

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    Alan Decho, a professor of microbial ecology at South Carolina University is a principal investigator on the NASA quorum sensing grant and worked with Prescott. He specializes in the study of biofilms.

    As a result, a main focus of quorum sensing research is on microbial mats and biofilms, the kind of slime-covered collections found most visibly in ponds and other waterways but most everywhere else too — on shower curtains, n the International Space Station orbiting the Earth, the plaque on your teeth, your cellphone and in fact in a number of places throughout our bodies. (Prescott makes a point of saying most bacteria are harmless, and even are essential for life.)

    Producing the protective biofilm mucus to make microbial “cities” is done as part of the quorum sensing process — an activity that helps create an environment that is more stable, with different cells or species doing different tasks. A bit like ants, perhaps, but on a microscopic level.

    The biofilms are also organized in part through quorum sensing in ways that result in bacteria that are more resistant to radiation being on the surface of the film while those that are harmed by oxygen would be found deeper in the mat.

    “Biofilm genes are controlled by quorum sensing,” Prescott told me. “Basically there has to be a lot of you for a mucus layer to make a difference, so microbes start making mucus once they sense other neighbors around.“

    Radiation protection provides a good model for how members of a mixed species biofilm will have different roles to play.

    ”The species that are more tolerate of radiation—or individual cells of same species—will exist at surface, and sometimes produce chemicals that are UV protectants. That also provides protection for others below that are less tolerate to UV. In addition, the biofilm mucus (exopolysaccahride) is a UV protectant itself.”

    “So certain members may be producing more mucus, while others are breaking down nutrients. Many biofilm researchers say biofilms are more like multi-cellular organisms than single cell, and it is certainly a step towards multicellularity.”

    And these organized activities are often coordinated through some sort of quorum sensing; i.e, chemical “talking.”

    7
    Biofilms made up of a variety of species did better than most other biological samples when exposed to space conditions on the International Space Station. (ESA)

    Armed with a protective covering and other community-based strengths, biofilms are adaptable. Consider, for instance, the inside of the International Space Station, some 250 miles above the Earth. Biofilms can be found there all the time, and not because they were purposefully brought up.

    5
    A Mars simulation chamber in the Edinburgh lab of Charles Cockell is used for testing which microbes and biofilms might survive harsh Martian conditions. (Charles Cockell)

    One batch of mixed bacterial biofilms, however, was intentionally delivered to the ISS for a European Space Agency-led study of bacterial microbes and larger species including fungi and lichen. The samples were exposed to the pressures, temperatures, radiation and more of space over a two-year period.

    While not all of the biofilm material survived and prospered, much of it did — more than most other samples.

    Prescott’s astrobiology work in Cockell’s Edinburgh lab will expose her collected biofilms to different but also harsh conditions — simulated Mars environments that can be changed to explore the effects of different conditions including extreme temperature, pressure, dryness, and radiation.

    The simulator is part of a cutting-edge effort to test microbes for potential future uses on Mars including manufacturing, “bio-mining,” and transforming elements available on Mars into a form that plants can use. Prescott will use the chamber to look for changes in the biofilm’s gene expression and quorum sensing under Mars conditions and will look at the AHL signaling molecules to see which species can maintain them.

    “We have no idea what will happen in the Mars environments; maybe they’ll die and maybe they’ll live,” she said. “And who knows? There may be quorum sensing systems on Mars different from anything we know.”

    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 11:36 am on May 4, 2019 Permalink | Reply
    Tags: "When it comes to planetary habitability it’s what’s inside that counts", A true picture of planetary habitability must consider how a planet’s atmosphere is linked to and shaped by what’s happening in its interior, Astrobiology, , , , , , , , ,   

    From Carnegie Institution for Science: “When it comes to planetary habitability, it’s what’s inside that counts” 

    Carnegie Institution for Science
    From Carnegie Institution for Science

    May 01, 2019

    Which of Earth’s features were essential for the origin and sustenance of life? And how do scientists identify those features on other worlds?

    A team of Carnegie investigators with array of expertise ranging from geochemistry to planetary science to astronomy published this week in Science an essay urging the research community to recognize the vital importance of a planet’s interior dynamics in creating an environment that’s hospitable for life.

    With our existing capabilities, observing an exoplanet’s atmospheric composition will be the first way to search for signatures of life elsewhere. However, Carnegie’s Anat Shahar, Peter Driscoll, Alycia Weinberger, and George Cody argue that a true picture of planetary habitability must consider how a planet’s atmosphere is linked to and shaped by what’s happening in its interior.

    1
    Reprinted with permission from Shahar et. al., Science Volume 364:3(2019).

    For example, on Earth, plate tectonics are crucial for maintaining a surface climate where life can thrive. What’s more, without the cycling of material between its surface and interior, the convection that drives the Earth’s magnetic field would not be possible and without a magnetic field, we would be bombarded by cosmic radiation.

    “We need a better understanding of how a planet’s composition and interior influence its habitability, starting with Earth,” Shahar said. “This can be used to guide the search for exoplanets and star systems where life could thrive, signatures of which could be detected by telescopes.”

    It all starts with the formation process. Planets are born from the rotating ring of dust and gas that surrounds a young star. The elemental building blocks from which rocky planets form—silicon, magnesium, oxygen, carbon, iron, and hydrogen—are universal. But their abundances and the heating and cooling they experience in their youth will affect their interior chemistry and, in turn, things like ocean volume and atmospheric composition.

    “One of the big questions we need to ask is whether the geologic and dynamic features that make our home planet habitable can be produced on planets with different compositions,” Driscoll explained.

    The Carnegie colleagues assert that the search for extraterrestrial life must be guided by an interdisciplinary approach that combines astronomical observations, laboratory experiments of planetary interior conditions, and mathematical modeling and simulations.

    2
    Artist’s impression of the surface of the planet Barnard’s Star b courtesy of ESO/M. Kornmesser.

    “Carnegie scientists are long-established world leaders in the fields of geochemistry, geophysics, planetary science, astrobiology, and astronomy,” said Weinberger. “So, our institution is perfectly placed to tackle this cross-disciplinary challenge.”

    In the next decade as a new generation of telescopes come online, scientists will begin to search in earnest for biosignatures in the atmospheres of rocky exoplanets. But the colleagues say that these observations must be put in the context of a larger understanding of how a planet’s total makeup and interior geochemistry determines the evolution of a stable and temperate surface where life could perhaps arise and thrive.

    “The heart of habitability is in planetary interiors,” concluded Cody.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage, in the broadest and most liberal manner, investigation, research, and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile.
    6.5 meter Magellan Telescopes located at Carnegie’s Las Campanas Observatory, Chile


    Carnegie Las Campanas 2.5 meter Irénée Dupont telescope, Atacama Desert, over 2,500 m (8,200 ft) high approximately 100 kilometres (62 mi) northeast of the city of La Serena,Chile


    Carnegie Institution Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena. near the north end of a 7 km (4.3 mi) long mountain ridge. Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile

    [/caption]

     
  • richardmitnick 10:10 am on April 28, 2019 Permalink | Reply
    Tags: Astrobiology, , , , , , , Jupiter's Europa moon, , , OPAG-Outer Planet Assessment Group   

    From Nautilus: “Why Europa Is the Place to Go for Alien Life” 

    Nautilus

    From Nautilus

    April 18, 2019
    Corey S. Powell

    1
    This image shows a view of the trailing hemisphere of Jupiter’s ice-covered satellite, Europa, in approximate natural color. Long, dark lines are fractures in the crust, some of which are more than 3,000 kilometers (1,850 miles) long. The bright feature containing a central dark spot in the lower third of the image is a young impact crater some 50 kilometers (31 miles) in diameter. This crater has been provisionally named “Pwyll” for the Celtic god of the underworld. Europa is about 3,160 kilometers (1,950 miles) in diameter, or about the size of Earth’s moon. This image was taken on September 7, 1996, at a range of 677,000 kilometers (417,900 miles) by the solid state imaging television camera onboard the Galileo spacecraft during its second orbit around Jupiter. The image was processed by Deutsche Forschungsanstalt fuer Luftund Raumfahrt e.V., Berlin, Germany. NASA/JPL/DLR.

    NASA/Galileo 1989-2003

    I have seen the future of space exploration, and it looks like a cue ball covered with brown scribbles. I am talking about Europa, the 1,940-mile-wide, nearly white, and exceedingly smooth satellite of Jupiter. It is an enigmatic world that is, in many ways, almost a perfect inversion of Earth. It is also one of the most plausible places to look for alien life. If it strikes you that those two statements sound rather contradictory—why yes, they do. And therein lies the reason why Europa just might be the most important world in the solar system right now. The Europa Clipper spacecraft is scheduled to launch in 2023 to probe the mysterious moon, according to NASA’s 2020 budget proposal.

    NASA/Europa Clipper annotated

    The unearthly aspects of Europa are literally un-earthly : This is an orb sculpted from water ice, not from rock. It has ice tectonics in place of shifting continents, salty ocean in place of mantle, and vapor plumes in place of volcanoes. The surface scribbles may be dirty ocean material that leaked up through the icy equivalent of an earthquake fault.

    From a terrestrial perspective, Europa is built all wrong, with its solid crust up top and water down below. From the perspective of alien life, though, that might be a perfectly dandy arrangement. Beneath its frozen crust, Europa holds twice as much liquid water as exists in all of our planet’s oceans combined. Astrobiologists typically flag water as life’s number-one requirement; well, Europa is drowning in it. Just below the ice line, conditions might resemble the environment on the underside of Antarctic ice sheets. At the bottom of its buried ocean, Europa may have an active system of hydrothermal vents. Both of these are vibrant habitats on Earth.

    Adding a new twist to the story, Europa’s water may sometimes escape its icy confines. On at least four occasions, the Hubble Space Telescope has detected what appear to be large plumes of water vapor erupting from Europa. That detection has confirmed and expanded on the scientific ideas about what makes Europa such a dynamic world. Europa travels in a slightly oval orbit around Jupiter, causing it to get alternately squeezed and stretched by the giant planet’s gravity. The flexing creates intense friction inside the satellite and generates enough heat to maintain a warm ocean beneath Europa’s frozen outer shell. The presence of a plume suggests that the stretching of Europa also opens and closes a network of fissures that allow buried water to erupt as geysers.

    If the geysers consist of ocean water shooting all the way through the crust, they could carry traces of aquatic life with them. And if the plumes rise high enough, a future spacecraft could fly right through them, sniffing for biochemicals.

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    SIGNS FROM BELOW: Salty seawater appears to have breached Europa’s frozen exterior, creating a network of red-brown streaks. Perhaps traces of aquatic life were carried along in the process? This scene is 100 miles wide. NASA/JPL-Caltech/SETI Institute

    You can see why people were giddy at a 2015 OPAG meeting held at NASA’s Ames Research Center. A regular forum for geeking out about ice worlds, the OPAG gatherings—short for Outer Planet Assessment Group—feel halfway between the corporate swarm of a MacWorld expo and a vinyl record fair. They are where true believers mingle with the newbies, showing off the latest science, kicking around speculative ideas, and developing strategies for exploration. With each new bit of data, they have grown increasingly convinced that Europa, not Mars, is the place to go to search for alien life. Finding the plume on Europa was another shot of adrenaline. The room went fervently silent as Lorenz Roth of Sweden’s Royal Institute of Technology, calling in via a fuzzy phone line, reported on the latest search for a recurrence of such water eruptions (no luck yet, alas).

    Another significant piece of news was hanging over the OPAG meeting: The discovery that Europa has plate tectonics, like Earth and unlike any other world we know of. Tectonics describes a process in which the crust moves about and cycles back and forth into the interior. Louise Prockter of Johns Hopkins University’s Applied Physics Laboratory co-discovered this style of activity on Europa by painstakingly reconstructing old images from the Galileo spacecraft, which circled Jupiter from 1995 to 2003. (Analysis of other Galileo data suggests the probe flew right past a Europan water plume in 1997, but scientists didn’t realize it at the time.)

    As Prockter explained to me at the meeting, a mobile crust potentially does two important things. It cycles surface ice, along with all the compounds it develops during exposure to the sun, down into the dark ocean; that chemical flow could be crucial for supplying the ocean with nutrients. The motion of the crust also brings ocean material up to the surface, where prying human eyes can seek clues about the Europan ocean without actually drilling down into it.

    Bolstered by these discoveries, the cult of Europa has now escaped the confines of the OPAG meetings. A successful mission to Europa would bring into focus the incredible ice-and-ocean environment of Europa. It would also help scientists understand ice worlds in general. Icy moons, dwarf planets, and giant asteroids are the norm in the vast outer zone of the solar system, and if they repeat the pattern of Europa they may contain much of the solar system’s habitable real estate. There is good reason to think that ice worlds are similarly abundant around other stars as well. Putting all of these new ideas together suggests that the Milky Way may collectively contain tens of billions of life-friendly iceboxes.

    But if these stunning extrapolations seem to suggest that scientists are starting to get a handle on how Europa works, allow me to suggest otherwise. Europa is still largely a big, icy ball of confusion.

    3
    Under the Ice: An artist’s conception of Europa (foreground), Jupiter (right) and Jupiter’s innermost large moon, Io (middle), shows salts bubbling up from Europa’s liquid ocean to reach its frozen surface. NASA/JPL-Caltech.

    Almost everything we know about the surface of Europa comes from NASA’s Galileo mission, which reached Jupiter in 1995. During its eight-year mission, Galileo mapped most of Europa, but at a crude resolution of about one mile per pixel. For comparison, today’s best Mars images show features as small as three feet. Elizabeth “Zibi” Turtle of the Hopkins Applied Physics Lab promises that the camera on NASA’s upcoming Europa probe will achieve a similar level of clarity. Until then, imagine trying to navigate using a map that doesn’t show anything smaller than one mile and you will get a sense of how far the Europa scientists have to go.

    What’s more, at a very basic level, planetary scientists still do not have a good handle on how geology (or maybe we should say “glaciology?”) works in frozen settings. Ice, you see, is not just ice. Robert Pappalardo of NASA’s Jet Propulsion Laboratory, the ponytail-wielding mission scientist for the agency’s upcoming Europa probe, spelled out some of the complexities to me. On Europa, surface temperatures on a warm day at the equator might rise up to -210 degrees Fahrenheit; at the poles, the lows plunge to -370 degrees Fahrenheit. Under those conditions, water is properly thought of as a mineral, and ice has approximately the consistency of concrete. In many ways it is remarkably similar to rock in how it fractures, faults, and shatters. But even in such a deep freeze, surface ice can sublimate—evaporate directly from solid to gas—in a way that rock does not. Icy material tends to boil off from darker, warmer regions and collect on lighter, cooler ones, producing an exotic kind of weathering that rearranges the landscape without any wind or rain.

    All sorts of other things are happening on the surface of Europa. Jupiter has a huge, potent magnetic field that bombards its satellite with radiation: about 500 rem per day on average, which you can more easily judge as a dose strong enough to make you sick in one hour and to kill you in 24. That radiation quickly breaks down any organic compounds, greatly complicating the search for life, but produces all kinds of other complex chemistry. A lab experiment at the Jet Propulsion Laboratory suggests that the colors of Europa’s streaks are produced by irradiated ocean salts. These and other fragmented molecules, along with a steady rain of organic material delivered by comet impacts, could be used as energy sources for life when they circulate back down into the ocean, where any living things would be well protected.

    The movement of Europa’s crust—its icy outer shell—is another broad area of mystery. On ice worlds, Pappalardo notes, water takes on the role of magma and hot rock deep below the surface, but once again ice and rock are not quite the same. Warm ice turns soft, almost slushy, under high pressure and slowly flows. There could be complicated circulation patterns contained entirely within the crust, which is perhaps 10 to 15 miles thick (or maybe more or less; that is yet another mystery that the Europa mission will investigate). Pools of liquid water might exist trapped within the shell, cut off from the underlying ocean. Plumes of water at the surface might not originate directly from the ocean; it is possible that they come from these intermediate lakes, analogous to the largely unexplored Lake Vostok in Antarctica.

    At the OPAG meeting, seemingly narrow arguments about the circulation of ice sparked colorful debates about prospects for life on Europa and, by extension, on the myriad other ice worlds out there. Britney Schmidt of Georgia Tech wondered if the active geology (glaciology) on Europa occurs entirely within the crust. If material does not circulate at all between surface and ocean, Europa is sealed tight. Life could not get any fresh chemicals from up above, and if it somehow manages to survive anyway we might never know unless we find a way to dig a hole all the way through. Several researchers at OPAG suggested that meaningful answers will require a surface lander; one energetic audience member repeatedly argued for sending an impactor—a high-speed bowling ball, essentially—to smack the surface and shake loose any possible buried microbes.

    As for the Europan ocean itself, that runs even deeper into what you might call aqua incognita . If the surface truly is streaked with salts, as the recent experiments indicate, that suggests a mineral-rich ocean in which waters interact vigorously with a rocky seafloor at the bottom. A likely source of such interaction is a network of hydrothermal vents powered by Europa’s internal heat; such vents could provide chemical energy to sustain Europan life, as they do on Earth. But how much total hydrothermal activity goes on? Are the acidity and salinity conducive to life? How much organic material is down there? The scientists egged each other on with provocative questions that, as yet, have no answers.

    When (or if) we will find out will depend, in large part, on how much of Europa’s inner nature is evident from the outside. The conversations at OPAG sometimes devolved into something resembling a college existential argument: If an alien swims in Europa’s ocean and nobody is able to see it, is it really alive?

    The Europa faithful have been waiting a long time for a mission that would wipe away those kinds of arguments, or at least ground them in hard data. That wait has been full of whipsaw swings between optimism and disappointment. NASA’s planned Europa Orbiter got a green light in 1999, only to be cancelled in 2002. The agency rebounded with a proposal for an even more ambitious, nuclear-propelled Jupiter Icy Moons Orbiter, which looked incredible until it got delayed and finally cancelled in 2006. A proposed joint venture with the European Space Agency never even got that far, though the Europeans are going ahead with their part of the project, which will send a probe to Ganymede, another one of Jupiter’s icy moons, in 2030.

    The Europa Clipper, outfitted with scientific instruments that include cameras and spectrometers, will swoop repeatedly past the moon and produce images that determine its composition. There is a chance the Europa mission will include a lander. Funding does not exist yet, but Adam Steltzner—the hearty engineer who figured out how to land the two-ton Curiosity rover safely on Mars—assures me that from a technical standpoint it would not be difficult to design a small probe equipped with rockets to allow a soft touchdown on Europa. There it could drill into the surface and search for possible organic material that has not been degraded by the radiation blasts from Jupiter.

    What you won’t see, the OPAG boffins all sadly agreed, is one of those cool Europa submarines that show up on the speculative “future mission concept” NASA web pages. Getting a probe into Lake Vostok right here on Earth has proven a daunting challenge. Drilling through 10 miles or more of Europan ice and exploring an alien ocean by remote control is something we still don’t know how to do, and certainly not with any plausible future NASA budget.

    No matter. Even the no-frills version of NASA’s current Europa plan will unleash a flood of information about how ice worlds work, and about how likely they are to support life. If the answers are as exciting as many scientists hope—and as I strongly expect—it will bolster the case for future missions to Titan, Enceladus, and some of Europa’s other beckoning cousins. It will reshape the search for habitable worlds around other stars as well. Right now astronomers are mostly focused on finding other Earthlike planets, but maybe that is not where most of the action is. Perhaps most of the life in the universe is locked away, safe but almost undetectable, beneath shells of ice.

    Whether or not Europa is home to alien organisms, it will tell us about the range of what life can be, and where it can be. That one icy moon will help cure science of its rocky-planet chauvinism. Hey, who you calling cue ball?

    See the full article here .

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    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 5:59 pm on February 25, 2019 Permalink | Reply
    Tags: Astrobiology, Creation of amino acids and alpha hydroxy acids in the lab is the culmination of nine years of research into the origins of life, Exoplanets - worlds beyond our reach but still within the realm of our telescopes - may have signatures of life in their atmospheres that could be revealed in the future., Future Mars missions could return samples from the Red Planet's rusty surface which may reveal evidence of amino acids formed by iron minerals and ancient water, JPL's Origins and Habitability Lab in Pasadena California, , NASA Study Reproduces Origins of Life on Ocean Floor", Their research focuses on how the building blocks of life form in hydrothermal vents on the ocean floor, They also removed the oxygen from the mixture because unlike today early Earth had very little oxygen in its ocean. The team additionally used the mineral iron hydroxide- "green rust" which was abunda, They combined water minerals and the "precursor" molecules pyruvate and ammonia which are needed to start the formation of amino acids, To re-create hydrothermal vents in the lab the team made their own miniature seafloors by filling beakers with mixtures that mimic Earth's primordial ocean, Understanding how far you can go with just organics and minerals before you have an actual cell is really important for understanding what types of environments life could emerge from   

    From JPL-Caltech: “NASA Study Reproduces Origins of Life on Ocean Floor” 

    NASA JPL Banner

    From JPL-Caltech

    February 25, 2019

    Arielle Samuelson
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-0307
    arielle.a.samuelson@jpl.nasa.gov

    1
    NASA Study Reproduces Origins of Life on Ocean Floor
    A time-lapse video of a miniature hydrothermal chimney forming in the lab, as it would in early Earth’s ocean. The chimney grows from reactions with minerals found in the ocean. Natural vents can continue to form for thousands of years and grow to tens of yards (meters) in height.Credit: NASA/JPL-Caltech/Flores

    2
    NASA Study Reproduces Origins of Life on Ocean Floor
    Laurie Barge, left, and Erika Flores, right, in JPL’s Origins and Habitability Lab in Pasadena, California.Credit: NASA/JPL-Caltech

    Scientists have reproduced in the lab how the ingredients for life could have formed deep in the ocean 4 billion years ago. The results of the new study offer clues to how life started on Earth and where else in the cosmos we might find it.

    Astrobiologist Laurie Barge and her team at NASA’s Jet Propulsion Laboratory in Pasadena, California, are working to recognize life on other planets by studying the origins of life here on Earth. Their research focuses on how the building blocks of life form in hydrothermal vents on the ocean floor.

    To re-create hydrothermal vents in the lab, the team made their own miniature seafloors by filling beakers with mixtures that mimic Earth’s primordial ocean. These lab-based oceans act as nurseries for amino acids, organic compounds that are essential for life as we know it. Like Lego blocks, amino acids build on one another to form proteins, which make up all living things.


    Hydrothermal vents are places in the seafloor where warm water from under the Earth’s crust mixes with near-freezing seawater. These vents form natural chimneys, which play host to all kinds of ocean life. Image Credit: MARUM/University of Bremen/NOAA-Pacific Marine Environmental Laboratory.

    “Understanding how far you can go with just organics and minerals before you have an actual cell is really important for understanding what types of environments life could emerge from,” said Barge, the lead investigator and the first author on the new study, published in the journal Proceedings of the National Academy of Sciences. “Also, investigating how things like the atmosphere, the ocean and the minerals in the vents all impact this can help you understand how likely this is to have occurred on another planet.”

    Found around cracks in the seafloor, hydrothermal vents are places where natural chimneys form, releasing fluid heated below Earth’s crust. When these chimneys interact with the seawater around them, they create an environment that is in constant flux, which is necessary for life to evolve and change. This dark, warm environment fed by chemical energy from Earth may be the key to how life could form on worlds farther out in our solar system, far from the heat of the Sun.

    “If we have these hydrothermal vents here on Earth, possibly similar reactions could occur on other planets,” said JPL’s Erika Flores, co-author of the new study.

    Barge and Flores used ingredients commonly found in early Earth’s ocean in their experiments. They combined water, minerals and the “precursor” molecules pyruvate and ammonia, which are needed to start the formation of amino acids. They tested their hypothesis by heating the solution to 158 degrees Fahrenheit (70 degrees Celsius) – the same temperature found near a hydrothermal vent – and adjusting the pH to mimic the alkaline environment. They also removed the oxygen from the mixture because, unlike today, early Earth had very little oxygen in its ocean. The team additionally used the mineral iron hydroxide, or “green rust,” which was abundant on early Earth.

    The green rust reacted with small amounts of oxygen that the team injected into the solution, producing the amino acid alanine and the alpha hydroxy acid lactate. Alpha hydroxy acids are byproducts of amino acid reactions, but some scientists theorize they too could combine to form more complex organic molecules that could lead to life.

    “We’ve shown that in geological conditions similar to early Earth, and maybe to other planets, we can form amino acids and alpha hydroxy acids from a simple reaction under mild conditions that would have existed on the seafloor,” said Barge.

    Barge’s creation of amino acids and alpha hydroxy acids in the lab is the culmination of nine years of research into the origins of life. Past studies looked at whether the right ingredients for life are found in hydrothermal vents, and how much energy those vents can generate (enough to power a light bulb). But this new study is the first time her team has watched an environment very similar to a hydrothermal vent drive an organic reaction. Barge and her team will continue to study these reactions in anticipation of finding more ingredients for life and creating more complex molecules. Step by step, she’s slowly inching her way up the chain of life.

    This line of research is important as scientists study worlds in our solar system and beyond that may host habitable environments. Jupiter’s moon Europa and Saturn’s moon Enceladus, for example, could have hydrothermal vents in oceans beneath their icy crusts. Understanding how life could start in an ocean without sunlight would assist scientists in designing future exploration missions, as well as experiments that could dig under the ice to search for evidence of amino acids or other biological molecules.

    Future Mars missions could return samples from the Red Planet’s rusty surface, which may reveal evidence of amino acids formed by iron minerals and ancient water. Exoplanets – worlds beyond our reach but still within the realm of our telescopes – may have signatures of life in their atmospheres that could be revealed in the future.

    “We don’t have concrete evidence of life elsewhere yet,” said Barge. “But understanding the conditions that are required for life’s origin can help narrow down the places that we think life could exist.”

    This research was supported by the NASA Astrobiology Institute, JPL Icy Worlds team.

    For more information on astrobiology at NASA, please visit:

    https://astrobiology.nasa.gov/

    See the full article here .


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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    Caltech Logo

    NASA image

     
  • richardmitnick 7:22 pm on November 9, 2018 Permalink | Reply
    Tags: Astrobiology, , , , , , , , , , , , , , Understanding our own backyard will be key in interpreting data from far-flung exoplanets   

    From COSMOS Magazine: “The tech we’re going to need to detect ET” 

    Cosmos Magazine bloc

    From COSMOS Magazine

    09 November 2018
    Lauren Fuge

    1
    Searching for biosignatures rather than examples of life itself is considered a prime strategy in the hunt for ET. smartboy10/Getty Images

    Move over Mars rovers, new technologies to detect alien life are on the horizon.

    A group of scientists from around the world, led by astrochemistry expert Chaitanya Giri from the Tokyo Institute of Technology in Japan, have put their heads together to plan the next 20 years’ worth of life-detection technologies. The study is currently awaiting peer review, but is freely available on the pre-print site, ArXiv.

    For decades, astrobiologists have scoured the skies and the sands of other planets for hints of extraterrestrial life. Not only are these researchers trying to find ET, but they’re also aiming to learn about the origin and evolution of life on Earth, the chemical composition of organic extraterrestrial objects, what makes a planet or satellite habitable, and more.

    But the answers to such questions are preceded by long years of planning, development, problem-solving and strategising.

    Late in 2017, 20 scientists from Japan, India, France, Germany and the USA – each with a special area of expertise – came together at a workshop run by the Earth-Life Science Institute (ELSI) at Giri’s Tokyo campus. There, they discussed the current progress and enticing possibilities of life-detection technologies.

    In particular, the boffins debated which ones should be a priority for research and development for missions within the local solar system – in other words, which instruments will be most feasible to out onto a space probe and send off to Mars or Enceladus during the next couple of decades.

    Of course, the planets and moons in the solar system are an extremely limited sample of the number of potentially habitable worlds in the universe, but understanding our own backyard will be key in interpreting data from far-flung exoplanets.

    So, according to these astrobiology experts, what’s the future plan for alien detection?

    The first step of any space mission is to study the planet or satellite from afar to determine whether it is habitable. Luckily, an array of next-generation telescopes is currently being built, from the ultra-sensitive James Webb Space Telescope, slated for launch in 2021, to the gargantuan Extremely Large Telescope in Chile, which will turn its 39-metre eye to the sky in 2024. The authors point out that observatories such as these will vastly expand our theoretical knowledge of planet habitability.

    NASA/ESA/CSA Webb Telescope annotated

    ESO/E-ELT,to be on top of Cerro Armazones in the Atacama Desert of northern Chile. located at the summit of the mountain at an altitude of 3,060 metres (10,040 ft).

    Just because a world is deemed habitable doesn’t mean life will be found all over it, though. It may exist only in limited geographical niches. To reach these inaccessible sites, the paper argues that we will require “agile robotic probes that are robust, able to seamlessly communicate with orbiters and deep space communications networks, be operationally semi-autonomous, have high-performance energy supplies, and are sterilisable to avoid forward contamination”.

    But according to Elizabeth Tasker, associate professor at the Japan Aerospace Exploration Agency (JAXA), who was not involved in the study, getting there is only half the struggle.

    “In fact, it’s the most tractable half because we can picture the problems we will face,” she says.

    The second, more pressing issue is how to recognise life unlike anything we know on Earth.

    As Tasker explains: “We only have Earth life to compare to and this is the result of huge evolutionary history on a planet whose complex past is unlikely to be replicated closely. That’s a lot of baggage to separate out.”

    According to the paper, the way forward is to equip missions with a suite of life-detection instruments that don’t look for life as we know it, but are instead able to identify the kinds of features that make organisms function.

    The authors outline a huge variety of exciting technologies that could be used for this purpose, including spectroscopy techniques (to analyse potential biological materials), quantum tunnelling [Nature Nanotechnology
    ] (to find DNA, RNA, peptides, and other small molecules), and fluorescence microscopy [ https://www.hou.usra.edu/meetings/lpsc2014/pdf/2744.pdf ](to identify the presence of cell membranes).

    They also nominate different forms of gas chromatography (to spot amino acids and sugars formed by living organisms, plus checking to see if molecules are “homochiral” [Space Science Reviews] (a suspected biosignature) using microfluidic devices and microscopes.

    High-resolution, miniaturised mass spectrometers would also be helpful, characterising biopolymers, which are created by living organisms, and measuring the elemental composition of objects to aid isotopic dating.

    Giri and colleagues also stress that exciting developments in machine learning, artificial intelligence, and pattern recognition will be useful in determining whether chemical samples are biological in origin.

    Interestingly, researchers are also developing technologies that may allow the detection of life in more unconventional places. On Earth, for example, cryotubes were recently used [International Journal of Systematic and Evolutionary Microbiology] to discover several new species of bacteria in the upper atmosphere.

    The scientists also discuss how certain technologies – such as high-powered synchrotron radiation and magnetic field facilities – are not yet compact enough to fly to other planets, and so samples must continue to be brought back for analysis.

    Several sample-and-return missions are currently underway, including JAXA’s Martian Moons exploration mission to Phobos, Hayabusa-2 to asteroid Ryugu, and NASA’s OSIRIS-rex to asteroid Bennu. What we learn from handling the organic-rich extraterrestrial materials brought back from these trips will be invaluable.

    JAXA MMX spacecraft

    JAXA/Hayabusa 2 Credit: JAXA/Akihiro Ikeshita

    NASA OSIRIS-REx Spacecraft

    What we learn from handling the organic-rich extraterrestrial materials brought back from these trips will be invaluable.

    The predictions and recommendations put forward by Giri and colleagues are the first steps in getting these technologies discussed in panel reviews, included in decadal surveys, and eventually funded.

    They complement several similar efforts, including a report prepared by US National Academies of Science, Engineering and Medicine (NASEM), calling for an expansion of the range of possible ET indicators, and a US-led exploration of how the next generation of radio telescopes will be utilised by SETI.

    Perhaps most importantly, these papers all highlight the need for collaborative work between scientists across disciplines.

    “A successful detection of life will need astrophysicists and geologists to examine possible environments on other planets, engineers and physicists to design the missions and instruments that can collect data, and chemists and biologists to determine how to classify life,” JAXA’s Tasker says.

    “But maybe that is appropriate: finding out what life really is and where it can flourish is the story of everyone on Earth. It should take all of us to unravel.”

    See the full article here .


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  • richardmitnick 10:52 am on October 15, 2018 Permalink | Reply
    Tags: Astrobiology, , , , , NASA Viking 2 Lander, , Search for Alien Life Should Be a Fundamental Part of NASA New Report Urges, , The Viking missions to Mars were the last time the space agency performed a direct explicit search for life on another world   

    From Scientific American: “Search for Alien Life Should Be a Fundamental Part of NASA, New Report Urges” 

    Scientific American

    From Scientific American

    October 15, 2018
    Adam Mann

    1
    An image taken by the Viking 2 lander from Utopia Planitia on the surface of Mars in 1976. The Viking missions to Mars were the last time the space agency performed a direct, explicit search for life on another world. Credit: NASA

    NASA Viking 2 Lander

    For decades many researchers have tended to view astrobiology as the underdog of space science. The field—which focuses on the investigation of life beyond Earth—has often been criticized as more philosophical than scientific, because it lacks in tangible samples to study.

    Now that is all changing. Whereas astronomers once knew of no planets outside our solar system, today they have thousands of examples. And although organisms were previously thought to need the relatively mild surface conditions of our world to survive, new findings about life’s ability to persist in the face of extreme darkness, heat, salinity and cold have expanded researchers’ acceptance that it might be found anywhere from Martian deserts to the ice-covered oceans of Saturn’s moon Enceladus.

    Highlighting astrobiology’s increasing maturity and clout, a new Congressionally mandated report from the National Academy of Sciences (NAS) [National Academies Press] urges NASA to make the search for life on other worlds an integral, central part of its exploration efforts. The field is now well set to be a major motivator for the agency’s future portfolio of missions, which could one day let humanity know whether or not we are alone in the universe. “The opportunity to really address this question is at a critically important juncture,” says Barbara Sherwood Lollar, a geologist at the University of Toronto and chair of the committee that wrote the report.

    The astronomy and planetary science communities are currently gearing up to each perform their decadal surveys—once-every-10-year efforts that identify a field’s most significant open questions—and present a wish list of projects to help answer them. Congress and government agencies such as NASA look to the decadal surveys to plan research strategies; the decadals, in turn, look to documents such as the new NAS report for authoritative recommendations on which to base their findings. Astrobiology’s reception of such full-throated encouragement now may boost its odds of becoming a decadal priority.

    Another NAS study released last month could be considered a second vote in astrobiology’s favor. This “Exoplanet Science Strategy” report recommended NASA lead the effort on a new space telescope that could directly gather light from Earth-like planets around other stars. Two concepts, the Large Ultraviolet/Optical/Infrared (LUVOIR) telescope and the Habitable Exoplanet Observatory (HabEx), are current contenders for a multibillion-dollar NASA flagship mission that would fly as early as the 2030s.

    NASA Large UV Optical Infrared Surveyor (LUVOIR)

    NASA Habitable Exoplanet Imaging Mission (HabEx) The Planet Hunter

    Either observatory could use a coronagraph, or “starshade”—objects that selectively block starlight but allow planetary light through—to search for signs of habitability and of life in distant atmospheres.

    NASA JPL Starshade

    NASA/WFIRST


    JPL-Caltech is developing coronagraph technology to enable direct imaging and spectroscopy of exoplanets using the Astrophysics Focused Telescope Assets (AFTA) on the NASA Wide-Field Infrared Survey Telescope (WFIRST).

    But either would need massive and sustained support from outside astrobiology to succeed in the decadal process and beyond.

    There have been previous efforts to back large, astrobiologically focused missions such as NASA’s Terrestrial Planet Finder concepts—ambitious space telescope proposals in the mid-2000s that would have spotted Earth-size exoplanets and characterized their atmospheres (if these projects had ever made it off the drawing board). Instead, they suffered ignominious cancellations that taught astrobiologists several hard lessons. There was still too little information at the time about the number of planets around other stars, says Caleb Scharf, an astrobiologist at Columbia University, meaning advocates could not properly estimate such a mission’s odds of success. His community had yet to realize that in order to do large projects it needed to band together and show how its goals aligned with those of astronomers less professionally interested in finding alien life, he adds. “If we want big toys,” he says. “We need to play better with others.”

    There has also been tension in the past between the astrobiological goals of solar system exploration and the more geophysics-steeped goals that traditionally underpin such efforts, says Jonathan Lunine, a planetary scientist at Cornell University. Missions to other planets or moons have limited capacity for instruments, and those specialized for different tasks often end up in ferocious competitions for a slot onboard. Historically, because the search for life was so open-ended and difficult to define, associated instrumentation lost out to hardware with clearer, more constrained geophysical research priorities. Now, Lunine says, a growing understanding of all the ways biological and geologic evolution are interlinked is helping to show that such objectives do not have to be at odds. “I hope that astrobiology will be embedded as a part of the overall scientific exploration of the solar system,” he says. “Not as an add-on, but as one of the essential disciplines.”

    Above and beyond the recent NAS reports, NASA is arguably already demonstrating more interest in looking for life in our cosmic backyard than it has for decades. This year the agency released a request for experiments that could be carried to another world in our solar system to directly hunt for evidence of living organisms—the first such solicitation since the 1976 Viking missions that looked for life on Mars. “The Ladder of Life Detection,” a paper written by NASA scientists and published in Astrobiology in June, outlined ways to clearly determine if a sample contains extraterrestrial creatures—a goal mentioned in the NAS report. The document also suggests NASA partner with other agencies and organizations working on astrobiological projects, as the space agency did last month when it hosted a workshop with the nonprofit SETI Institute on the search for “techno-signatures,” potential indicators of intelligent aliens.



    “I think astrobiology has gone from being something that seemed fringy or distracting to something that seems to be embraced at NASA as a major touchstone for why we’re doing space exploration and why the public cares,” says Ariel Anbar, a geochemist at Arizona State University in Tempe.

    All this means is astrobiology’s growing influence is helping bring what once were considered outlandish ideas into reality. Anbar recalls attending a conference in the early 1990s, when then–NASA Administrator Dan Goldin displayed an Apollo-era image of Earth from space and suggested the agency try to do the same thing for a planet around another star.

    “That was pretty out there 25 years ago,” he says. “Now it’s not out there at all.”

    See the full article here .


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    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
  • richardmitnick 12:54 pm on August 2, 2018 Permalink | Reply
    Tags: , Astrobiology, , , , , , Life on moon Titan   

    From Astrobiology Magazine via EarthSky: “Where to look for life on Titan” 

    http://www.astrobio.net/

    1

    From EarthSky

    August 2, 2018
    Paul Scott Anderson

    1
    Saturn’s largest moon Titan as seen by the Cassini spacecraft. This world’s liquid methane and ethane rivers, lakes and seas might support some kind of life, and scientists now think they know the best places to look. Image via NASA/JPL-Caltech.

    NASA/ESA/ASI Cassini-Huygens Spacecraft

    NASA’s Cassini spacecraft and ESA’s Huygens lander showed that Saturn’s large moon Titan mimics Earth in many ways. But Titan displays different kinds of chemistry in a far colder environment. Given the similarities, the question of life inevitably arises: could Titan support some kind of simple life? Given the differences, scientists ponder the best places to look for Titan life. In late July 2018, a new study published in the peer-reviewed journal Astrobiology and reported on in Astrobiology Magazine suggests the best places on Titan to look for evidence of life.

    Titan is a geological wonderland for planetary scientists. It has rivers, lakes and seas of actual liquid – not water, but the hydrocarbons methane and ethane – and it has mountain ranges, possible ice volcanoes (aka cryovolcanoes) and vast hydrocarbon dunes. There is also evidence for a subsurface ocean of water, similar to those believed to lie beneath the surface of Jupiter’s moon Europa and Saturn’s moon Enceladus.

    Perhaps surprisingly, the research team, led by Catherine Neish, a planetary scientist specializing in impact cratering at the University of Western Ontario, suggested that the best locations to look for life on Titan would not be the lakes or seas. Instead, the new work shows a better place to look would be within impact craters and cryovolcanoes on Titan.

    The scientists reason that these areas are where water ice in Titan’s crust could temporarily melt into a liquid. Water is still the only solvent known to be able to support life as we know it.

    2
    A large, fairly young crater on Titan, about 25 miles (40 km) in diameter. Such craters could temporarily melt frozen water in the crust, providing an environment for pre-biotic or biotic molecules to form. Image via NASA/JPL-Caltech.

    Various studies have suggested that liquid methane and ethane could support life. But Saturn’s moon Titan – some nine astronomical units farther from the sun than Earth – is very cold, with surface temperatures hovering around -300 degrees Fahrenheit (–179 degrees Celsius). Methane and ethane do remain liquid at Titan’s surface temperature, but it’s too cold there for biochemical processes, at least as far as we know (although that, too, is a matter of debate).

    Titan’s surface is also covered with tholins, which are large, complex organic molecules produced when gases are subjected to cosmic radiation. When mixed with liquid water, tholins can produce amino acids, which are, essentially, life’s building blocks. According to researcher Morgan Cable at NASA’s Jet Propulsion Laboratory in Pasadena, California:

    “When we mix tholins with liquid water, we make amino acids really fast. So any place where there is liquid water on Titan’s surface or near its surface could be generating the precursors to life – biomolecules – that would be important for life as we know it, and that’s really exciting.”

    The temperatures on Titan’s surface are too cold for liquid water, so where could it be found? The answer is Titan’s craters and cryovolcanoes. The processes involved with both of these geologic features can melt water ice into liquid, even if only temporarily.

    But that might be enough for more complex organic molecules like amino acids to form.

    3
    Sotra Facula is a possible cryovolcano on Titan, one of the few candidates known. Image via NASA/JPL–Caltech/USGS/University of Arizona.

    4
    Another view of Sotra Facula. This image was built from radar topography with infrared colors overlaid on top. Image via NASA/JPL–Caltech/USGS/University of Arizona.

    Between craters and cryovolcanoes, it would seem that craters would be the most ideal location for pre-biotic or biotic chemistry to occur. As Neish explained:

    “Craters really emerged as the clear winner for three main reasons. One, is that we’re pretty sure there are craters on Titan. Cratering is a very common geologic process and we see circular features that are almost certainly craters on the surface.’

    Neish also noted that craters would produce more liquid water melt than a cryovolcano, so any water would remain liquid for a longer period of time. She also added:

    “The last point is that impact craters should produce water that’s at a higher temperature than a cryovolcano.”

    Warmer water would allow for faster chemical reaction rates, which would help in the creation of prebiotic or even biotic molecules. The largest known craters on Titan are Sinlap (70 miles/112 kms in diameter), Selk (56 miles/90 kms) and Menrva (244 miles/392 kms). These would be the primary locations to look for biomolecules.

    David Grinspoon at the Planetary Science Institute isn’t convinced yet, however. He commented:

    “We don’t know where to search even with results like this. I wouldn’t use it to guide our next mission to Titan. It’s premature.”

    5
    Titan is well-known for its lakes and seas of liquid methane/ethane, such as Ligiea Mare, shown here. Image via NASA/JPL-Caltech/ASI/Cornell.

    So what about cryovolcanoes? They haven’t actually been confirmed yet to exist on Titan, and if they do, they are more rare than craters (even though craters are also relatively rare on Titan). The most likely feature to be a cryovolcano is a mountain with a caldera on top called Sotra Facula. Other than that, they seem to be few and far between. As Neish said:

    “Cryovolcanism is the harder thing to do and there is very little evidence of it on Titan.”

    6
    Diagram illustrating how biosignatures could also be transported from the subsurface ocean to the surface of Titan. Image via Athanasios Karagiotas/Theoni Shalamberidze.

    There is also, of course, a possible subsurface ocean of water on Titan, but, if it exists, it is deep below the moon’s surface and inaccessible to any robotic probes in the near future. For now, we can only imagine what might be in that alien abyss.

    The methane/ethane lakes and seas should still be explored too; they are the only other known bodies of liquid on the surface of another moon or planet in the solar system. Methane-based life could theoretically exist in such environments, so it would obviously be a good idea to look, at least.

    Bottom line: Titan is a world that is eerily similar to Earth in some ways, yet still uniquely alien. Whether it supports any kind of life is still a big question, but researchers now think they know the best places to search for it.

    See the full article here .


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    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

     
  • richardmitnick 10:20 am on June 26, 2018 Permalink | Reply
    Tags: Astrobiology, , , , , NASA Asks: Will We Know Life When We See It?, , ,   

    From JPL-Caltech and U Washington: “NASA Asks: Will We Know Life When We See It?” 

    NASA JPL Banner

    June 25, 2018
    NASA:

    Calla Cofield
    Jet Propulsion Laboratory, Pasadena, California
    818-393-1821
    Calla.e.cofield@jpl.nasa.gov

    Felicia Chou
    NASA Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov 2018-147

    U Washington
    Peter Kelley

    From JPL-Caltech

    1
    This image is an artist’s conception of what life could look like on the surface of a distant planet. Credit: NASA

    2
    Life can leave “fingerprints” of its presence in the atmosphere and on the surface of a planet. These potential signs of life, or biosignatures, can be detected with telescopes. Credit: NASA/Aaron Gronstal

    3
    Abiotic processes can fool us into thinking a barren planet is alive. Rather than measuring a single characteristic of a planet, we should consider a suite of traits to build the case for life. Credit: NASA/Aaron Gronstal

    4
    NASA Asks: Will We Know Life When We See It?
    Since the data we collect from planets will be limited, scientists will quantify how likely a planet has life based on all the available evidence. Follow-up observations are required for confirmation. Credit: NASA/Aaron Gronstal

    In the last decade, we have discovered thousands of planets outside our solar system and have learned that rocky, temperate worlds are numerous in our galaxy. The next step will involve asking even bigger questions. Could some of these planets host life? And if so, will we be able to recognize life elsewhere if we see it?

    A group of leading researchers in astronomy, biology and geology has come together under NASA’s Nexus for Exoplanet System Science, or NExSS, to take stock of our knowledge in the search for life on distant planets and to lay the groundwork for moving the related sciences forward.

    “We’re moving from theorizing about life elsewhere in our galaxy to a robust science that will eventually give us the answer we seek to that profound question: Are we alone?” said Martin Still, an exoplanet scientist at NASA Headquarters, Washington.

    In a set of five review papers published last week in the scientific journal Astrobiology, NExSS scientists took an inventory of the most promising signs of life, called biosignatures. The paper authors include four scientists from NASA’s Jet Propulsion Laboratory in Pasadena, California. They considered how to interpret the presence of biosignatures, should we detect them on distant worlds. A primary concern is ensuring the science is strong enough to distinguish a living world from a barren planet masquerading as one.

    The assessment comes as a new generation of space and ground-based telescopes are in development. NASA’s James Webb Space Telescope will characterize the atmospheres of some of the first small, rocky planets. There are plans for other observatories — such as the Giant Magellan Telescope and the Extremely Large Telescope, both in Chile — to carry sophisticated instruments capable of detecting the first biosignatures on faraway worlds.

    Through their work with NExSS, scientists aim to identify the instruments needed to detect potential life for future NASA flagship missions. The detection of atmospheric signatures of a few potentially habitable planets may possibly come before 2030, although determining whether the planets are truly habitable or have life will require more in-depth study.

    Since we won’t be able to visit distant planets and collect samples anytime soon, the light that a telescope observes will be all we have in the search for life outside our solar system. Telescopes can examine the light reflecting off a distant world to show us the kinds of gases in the atmosphere and their “seasonal” variations, as well as colors like green that could indicate life.

    These kinds of biosignatures can all be seen on our fertile Earth from space, but the new worlds we examine will differ significantly. For example, many of the promising planets we have found are around cooler stars, which emit light in the infrared spectrum, unlike our sun’s high emissions of visible-light.

    “What does a living planet look like?” said Mary Parenteau, an astrobiologist and microbiologist at NASA’s Ames Research Center in Silicon Valley and a co-author. “We have to be open to the possibility that life may arise in many contexts in a galaxy with so many diverse worlds — perhaps with purple-colored life instead of the familiar green-dominated life forms on Earth, for example. That’s why we are considering a broad range of biosignatures.”

    The scientists assert that oxygen — the gas produced by photosynthetic organisms on Earth — remains the most promising biosignature of life elsewhere, but it is not foolproof. Abiotic processes on a planet could also generate oxygen. Conversely, a planet lacking detectable levels of oxygen could still be alive – which was exactly the case of Earth before the global accumulation of oxygen in the atmosphere.

    “On early Earth, we wouldn’t be able to see oxygen, despite abundant life,” said Victoria Meadows, an astronomer at the University of Washington in Seattle and lead author of one of the papers. “Oxygen teaches us that seeing, or not seeing, a single biosignature is insufficient evidence for or against life — overall context matters.”

    Rather than measuring a single characteristic, the NExSS scientists argue that we should be looking at a suite of traits. A planet must show itself capable of supporting life through its features, and those of its parent star.

    The NExSS scientists will create a framework that can quantify how likely it is that a planet has life, based on all the available evidence. With the observation of many planets, scientists may begin to more broadly classify the “living worlds” that show common characteristics of life, versus the “non-living worlds.”

    “We won’t have a ‘yes’ or ‘no’ answer to finding life elsewhere,” said Shawn Domagal-Goldman, an astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a co-author. “What we will have is a high level of confidence that a planet appears alive for reasons that can only be explained by the presence of life.”

    U Washington

    From University of Washington

    June 25, 2018

    For more information, contact
    Victoria Meadows at vsm@astro.washington.edu or
    Catling at dcatling@uw.edu.

    Researchers with the University of Washington-led Virtual Planetary Laboratory are central to a group of papers published by NASA researchers in the journal Astrobiology outlining the history — and suggesting the future — of the search for life on exoplanets, or those orbiting stars other than the sun.

    The research effort is coordinated by NASA’s Nexus for Exoplanet Systems Science, or NExSS, a worldwide network dedicated to finding new ways to study the age-old question: “Are we alone?”

    A theme through the research and the discussions behind it is the need to consider planets in an integrated way, involving multiple disciplines and perspectives.

    “For life to be detectable on a distant world it needs to strongly modify its planet in a way that we can detect,” said UW astronomy professor Victoria Meadows, lead author of one of the papers and principle investigator of the Virtual Planetary Laboratory, or VPL for short. “But for us to correctly recognize life’s impact, we also need to understand the planet and star — that environmental context is key.”

    Work done by NExSS researchers will help identify the measurements and instruments needed to search for life using future NASA flagship missions. The detection of atmospheric signatures of a few potentially habitable planets may possibly come before 2030, although whether the planets are truly habitable or have life will require more in-depth study.

    The papers result from two years of effort by some of the world’s leading researchers in astrobiology, planetary science, Earth science, heliophysics, astrophysics, chemistry and biology, including several from the UW and the Virtual Planetary Laboratory, or VPL. The coordinated work was born of online meetings and an in-person workshop held in Seattle in July of 2016.

    The pace of exoplanet discoveries has been rapid, with over 3,700 detected since 1992. NASA formed the international NExSS network to focus a variety of disciplines on understanding how we can characterize and eventually search for signs of life, called biosignatures, on exoplanets.

    The NExSS network has furthered the field of exoplanet biosignatures and “fostered communication between researchers searching for signs of life on solar system bodies with those searching for signs of life on exoplanets,” said Niki Parenteau, an astrobiologist and microbiologist at NASA’s Ames Research Center, Moffett Field, California, and a VPL team member. “This has allowed for sharing of ‘lessons learned’ by both communities.”

    The first of the papers [links for all papers are below] reviews types of signatures astrobiologists have proposed as ways to identify life on an exoplanet. Scientists plan to look for two major types of signals: One is in the form of gases that life produces, such as oxygen made by plants or photosynthetic microbes. The other could come from the light reflected by life itself, such as the color of leaves or pigments.

    Such signatures can be seen on Earth from orbit, and astronomers are studying designs of telescope concepts that may be able to detect them on planets around nearby stars. Meadows is a co-author, and lead author is Edward Schwieterman, a VPL team member who earned his doctorate in astronomy and astrobiology from the UW and is now a post-doctoral researcher at the University of California, Riverside.

    Meadows is lead author of the second review paper, which discusses recent research on “false positives” and “false negatives” for biosignatures, or ways nature could “trick” scientists into thinking a planet without life was alive, or vice versa.

    In this paper, Meadows and co-authors review ways that a planet could make oxygen abiotically, or without the presence of life, and how planets with life may not have the signature of oxygen that is abundant on modern-day Earth.

    The paper’s purpose, Meadows said, was to discuss these changes in our understanding of biosignatures and suggest “a more comprehensive” treatment. She said: “There are lots of things in the universe that could potentially put two oxygen atoms together, not just photosynthesis — let’s try to figure out what they are. Under what conditions are they are more likely to happen, and how can we avoid getting fooled?”

    Schwieterman is a co-author on this paper, as well as UW doctoral students Jacob Lustig-Yaeger, Russell Deitrick and Andrew Lincowski.

    With such advance thinking, scientists are now better prepared to distinguish false positives from planets that truly do host life.

    Two more papers show how scientists try to formalize the lessons we have learned from Earth, and expand them to the wide diversity of worlds we have yet to discover.

    David Catling, UW professor of Earth and space sciences, is lead author on a paper that proposes a framework for assessing exoplanet biosignatures, considering such variables as the chemicals in the planet’s atmosphere, the presence of oceans and continents and the world’s overall climate. Doctoral student Joshua Krissansen-Totton is a co-author.

    By combining all this information in systematic ways, scientists can analyze whether data from a planet can be better explained statistically by the presence of life, or its absence.

    “If future data from an exoplanet perhaps suggest life, what approach can distinguish whether the existence of life is a near-certainty or whether the planet is really as dead as a doornail?” said Catling. “Basically, NASA asked us to work out how to assign a probability to the presence of exoplanet life, such as a 10, 50 or 90 percent chance. Our paper presents a general method to do this.”

    The data that astronomers collect on exoplanets will be sparse. They will not have samples from these distant worlds, and in many cases will study the planet as a single point of light. By analyzing these fingerprints of atmospheric gases and surfaces embedded in that light, they will discern as much as possible about the properties of that exoplanet.

    “Because life, planet, and parent star change with time together, a biosignature is no longer a single target but a suite of system traits,” said Nancy Kiang, a biometeorologist at NASA’s Goddard Institute for Space Studies in New York and a VPL team member. She said more biologists and geologists will be needed to interpret observations “where life processes will be adapted to the particular environmental context.”

    The final article discusses the ground-based and space-based telescopes that astronomers will use to search for life beyond the solar system. This includes a variety of observatories, from those in operation today to ones that will be built decades in the future.

    Taken together, this cluster of papers explains how the exoplanet community will evolve from their current assessments of the sizes and orbits of these faraway worlds, to thorough analysis of their chemical composition and eventually whether they harbor life.

    “I’m excited to see how this research progresses over the coming decades,” said Shawn Domagal-Goldman, an astrobiologist at NASA’s Goddard Space Flight Center, Greenbelt, Maryland, and a VPL team member. He is also a co-author on four of the five papers.

    “NExSS has created a diverse network of scientists. That network will allow the community to more rigorously assess planets for biosignatures than would have otherwise been possible.”

    NExSS is an interdisciplinary, cross-divisional NASA research coordination network.

    Science papers in journal Astrobiology:

    Exoplanet Biosignatures: At the Dawn of a New Era of Planetary Observations
    Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment
    Exoplanet Biosignatures: A Review of Remotely Detectable Signs of Life
    Exoplanet Biosignatures: A Framework for Their Assessment
    Exoplanet Biosignatures: Observational Prospects
    Exoplanet Biosignatures: Future Directions

    See the full NASA article here .
    See the full U Washington article here .


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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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    NASA image

     
  • richardmitnick 2:40 pm on June 7, 2018 Permalink | Reply
    Tags: Astrobiology, , , , ,   

    From Many Worlds: “Breakthrough Findings on Mars Organics and Mars Methane” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    2018-06-07
    Marc Kaufman

    NASA Mars Curiosity Rover

    After almost six years of searching, drilling and analyzing on Mars, the Curiosity rover team has conclusively detected three types of naturally-occurring organics that had not been identified before on the planet.

    The Mars organics Science paper by NASA’s Jennifer Eigenbrode and much of the rover’s Sample Analysis on Mars (SAM) instrument team was twinned with another paper describing the discovery of a seasonal pattern to the release of the simple organic gas methane on Mars.

    This finding is also a major step forward not only because it provides ground truth for the difficult question of whether significant amounts of methane are in the Martian atmosphere, but equally important it determines that methane concentrations appear to change with the seasons. The implications of that seasonality are intriguing, to say the least.

    In an accompanying opinion piece in Science, Inges Loes ten Kate of Utrecht University in Netherlands wrote of the two papers: “Both these findings are breakthroughs in astrobiology.”

    2
    Remains of 3.5 billion-year old lake that once filled Gale Crater. NASA scientists concluded early in the Curiosity mission that the planet was habitable long ago based on the study of mudstone remains like these. (NASA/JPL-Caltech/MSSS).

    Finding organic compounds on Mars has been a prime goal of the Curiosity rover mission.

    Those carbon-based compounds surely fall from the sky on Mars, as they do on Earth and everywhere else, but identifying them has proven illusive.

    The consequences of that non-discovery have been significant. Going back to the Viking missions of 1976, scientists concluded that life was not possible on Mars because there were no organics, or none that were detected.

    But the reasons for the disappearing organics are pretty well understood. Without much of an atmosphere to protect it, the Martian surface is bombarded with ultraviolet radiation, which can destroy organic compounds. Or, in the case of the samples discovered by the SAM team, large organic macromolecules — the likes of proteins, membranes and DNA — are broken up into much smaller pieces.

    That’s what the team found, Eigenbrode told me. The organics were probably preserved, she said, because of exceptionally high levels of sulfur present in that part of Gale Crater.

    The organics, extracted from mudstone at the Mojave and Confidence Hill sites, had bonded tightly with ancient non-organic material. The organic material was freed to be collected as gas only after being exposed to temperatures of more than 500 to 800 centigrade in the SAM oven.

    “This material was buried for billions of years and then exposed to extreme surface conditions, so there’s a limit to what we can learn about. Did it come from life? We don’t know.

    “But the fact we found the organic carbon adds to the habitability equation. It was in a lake environment that we know could have supported life. Organics are things that organisms can eat.”

    It will take different kinds of instruments and samples from drilling deeper into the extreme Martian surface to answer the question of whether the organics came from living microbes. But for Eigenbrode, future answers of either “yes” or “no” are almost equally interesting.

    Finding clear signs of early Martian life would certainly be hugely important, she said. But a conclusion that Mars never had life — although it had conditions some 3.5 to 3.8 billion years ago quite similar to conditions on Earth at that time — raises the obvious question of “why not?”

    3
    NASA’s Curiosity rover raised robotic arm with drill pointed skyward while exploring Vera Rubin Ridge at the base of Mount Sharp inside Gale Crater. This navcam camera mosaic was stitched from raw images taken on Sol 1833, Oct. 2, 2017 and colorized. (NASA/JPL-Caltech/Ken Kremer, Marco Di Lorenzo)

    Organic molecules are the building blocks of all known life on Earth, and consist of a wide variety of molecules made primarily of carbon, hydrogen, and oxygen atoms. However, organic molecules can also be made by chemical reactions that don’t involve life.

    Examples of non-biological sources include chemical reactions in water at ancient Martian hot springs or delivery of organic material to Mars by interplanetary dust or fragments of asteroids and comets.

    It needs to be said that today’s Mars organics announcement was not the first we have heard. In 2014, a NASA team reported the presence of chlorine-based organics in Sheepbed mudstone at Yellowknife Bay, the first ancient Mars lake visited by Curiosity.

    That work, led by NASA Goddard scientists Caroline Freissinet and Daniel Glavin and published in the Journal of Geophysical Research, focused on signatures from unusual organics not seen naturally on Earth.

    The organics were complex and made entirely of Martian components, the paper reported. But because they combined chlorine with the organic hydrocarbons, they are not considered to be as “natural” as the discovery announced today.

    And when it comes to organics on Mars, the complicated history of research into the presence of the gas methane (a simple molecule that consists of carbon and hydrogen) also shows the great challenges involved in making these measurements on Mars.

    4
    By measuring absorption of light at specific wavelengths, the tunable laser spectrometer on Curiosity measures concentrations of methane, carbon dioxide and water vapor in the Martian atmosphere. (NASA)

    4
    The gold-plated Sample Analysis on Mars contains three instruments that make the measurements of organics and methane. (NASA/Goddard Space Flight Center)

    The second Science paper, authored by Chris Webster of NASA’s Jet Propulsion Lab and colleagues, reports that the gas methane has been detected regularly in recent years, with surprising seasonality.

    “The history of Mars methane has been frustrating, with reports of some large plumes and spikes detected, but none have been repeatable. It’s almost like they’re random,” he told me. “But now we can see a large seasonal cycle in the background of these detections, and that’s extremely important.”

    Over three Mars years, or almost five Earth years, Webster said there have been significant increases in methane detected during the summer, and especially the late summer. That tripling of the methane counts is considered too great to be random, especially since the count declines as predicted after the summer ends.

    No definite explanation of why this happens has emerged yet, but one theory has been embraced by some scientists.

    While it is still cold in the Martian summer, it can get warm enough where the sun shines directly on a collection of ice for some melting to occur. And that melting, the paper reports, could provide an escape valve for methane collected long ago under the surface. The process is termed “microseepage.”

    5
    This illustration shows the ways in which methane from the subsurface might find its way to the
    surface where its release could produce the large seasonal variation in the atmosphere
    as observed by Curiosity. Potential methane sources include byproducts from organisms alive or long dead, ultraviolet degradation of organics, or water-rock chemistry; and its losses include atmospheric photochemistry and surface reactions. Seasons refer to the northern hemisphere. The plotted data is from Curiosity’s TLS-SAM instrument, and the curved line through the data is to aid the eye. (NASA/JPL-Caltech)

    Methane is a crucial organic in astrobiology because most of that gas found on Earth comes from biology, although various non-biological processes can produce methane as well.

    Today’s paper by Webster et al is the third in Science on Mars methane as measured by Curiosity, and it is the first to find a seasonal pattern. The first paper, in 2013 Science, actually reported there was no methane measured in early runs, a conclusion that led to push-back from many of those working in the field.

    While the Mars methane results released today are being described as a “breakthrough,” they follow closely the findings of a Science paper in 2009 by Michael Mumma and Geronimo Villanueva, both at NASA Goddard.

    The two reported then similar findings of plumes of methane on Mars, of a seasonality associated with their distribution, and a similar conclusion that the methane probably was coming from subsurface reservoirs. Like Webster et al, Mumma and Villanueva said they were unable to determine if the source of methane was biological or geological.

    The methane levels in the plumes they found were considerably higher than detected so far by Curiosity, but what they were detecting was quite different. Using ground-based telescopes, they detected the high concentrations in two specific areas over a number of years, while Curiosity is measuring methane levels that are more global or regional.

    Just as Webster was criticized for his initial paper saying there was no methane detected on Mars, the Mumma team also got sharp questions about their methodology and conclusions. This grew as their numerous follow-up efforts to detect the Mars methane proved unsuccessful.

    But now Webster says the Curiosity findings have essentially “confirmed” what Mumma and Villanueva reported nine years ago.

    Still, the Curiosity results are a breakthrough because they were made on Mars rather than through a telescope. Mumma, who described the new Curiosity results as “satisfying,” agreed that they were a major step forward.

    “This is how science works,” he said. “We do our work and put out our papers and other scientists react. We take it all in and make changes if needed. But the big changes come when new, and maybe different, data is presented.”

    And that’s exactly what will be happening soon regarding methane on Mars. Beginning early this year, the European/Russian Trace Gas Orbiter (TGO) has been collecting data specifically on Mars gases including methane. Unlike previous Mars methane campaigns, this one can potentially determine whether the methane being released from below the surface was formed by biology or geology — although not without great difficulty.

    Mumma, who is part of that TGO team, said the first release of information is due in the fall.

    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.

     
    • stewarthoughblog 12:28 am on June 8, 2018 Permalink | Reply

      Fascinating results and science from exploration and experiments on Mars. Understanding that much of the funding justification is predicated on the possibility of hopefully finding evidence of life, past or present, the whole thing is seriously over-optimistic and not scientifically based on reality. Proposing Mars was once habitable to a level similar on Earth is extremely speculative, especially considering that primordial Earth conditions are not comprehensively understood. More importantly, there are no naturalistic processes capable of creating life, no matter the planet examined. Consequently, the only life found on Mars will be Earth effluent.

      Like

      • richardmitnick 12:01 pm on June 8, 2018 Permalink | Reply

        To be honest, I do not know why we spend so much time and money on Mars exploration.

        Like

        • stewarthoughblog 11:31 pm on June 8, 2018 Permalink

          I believe it is because no other solar system body is as approachable and accessible, and no other is as close to Earth parametrically, so no other is likely to have replicated the conditions of primordial Earth when the first life arose. Since determining the origin of life and the possibility of it ever having existed anywhere in the universe is arguably the greatest desire of humanity to find out, that is why Mars is so intriguing.Virtually all space missions are striving to learn about life, and it is a sexier topic than geology and atmospheres, it is thrown out continually to promote funding.

          Like

  • richardmitnick 5:31 pm on June 5, 2018 Permalink | Reply
    Tags: , Astrobiology, , , ENIGMA-Evolution of Nanomachines in Geospheres and Microbial Ancestors, ,   

    From Rutgers: “NASA Funds Rutgers Scientists’ Pursuit of the Origins of Life” 

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    Our Great Seal.

    From Rutgers University

    [THIS POST IS DEDICATED TO L.Z. OF RUTGERS AND HP FOR HIS UNENDING SUPPORT OF THIS BLOG AND PHYSICS AT RUTGERS UNIVERSITY]

    Jun 4, 2018

    Todd Bates
    848-932-0550
    todd.bates@rutgers.edu

    Rutgers-led ENIGMA team examines whether “protein nanomachines” in our cells arose before life on Earth, other planets.

    What are the origins of life on Earth and possibly elsewhere? Did “protein nanomachines” evolve here before life began to catalyze and support the development of living things? Could the same thing have happened on Mars, the moons of Jupiter and Neptune, and elsewhere in the universe?

    A Rutgers University-led team of scientists called ENIGMA, for “Evolution of Nanomachines in Geospheres and Microbial Ancestors,” will try to answer those questions over the next five years, thanks to an approximately $6 million NASA grant and membership in the NASA Astrobiology Institute.

    Rutgers Today asked Paul G. Falkowski, ENIGMA principal investigator and a distinguished professor at Rutgers University–New Brunswick, about research on the origins of life.

    1
    Iron- and sulfur-containing minerals found on the early Earth (greigite, left, is one example) share a remarkably similar molecular structure with metals found in modern proteins (ferredoxin, right, is one example). Did the first proteins at the dawn of life on Earth interact directly with rocks to promote catalysis of life?
    Image: Professor Vikas Nanda/Center for Advanced Biotechnology and Medicine at Rutgers

    What is astrobiology?

    It is the study of the origins of life on Earth and potential life on planets – called extrasolar planets – and planetary bodies like moons in our solar system and other solar systems. More than 3,700 extrasolar planets have been confirmed in the last decade or so. Many of these are potentially rocky planets that are close enough to their star that they may have liquid water, and we want to try and understand if the gases on those planets are created by life, such as the oxygen on Earth.

    What is the ENIGMA project?

    All life on Earth depends on the movement of electrons; life literally is electric. We breathe in oxygen and breathe out water vapor and carbon dioxide, and in that process we transfer hydrogen atoms, which contain a proton and an electron, to oxygen to make water (H20). We move electrons from the food we eat to the oxygen in the air to derive energy. Every organism on Earth moves electrons to generate energy. ENIGMA is a team of primarily Rutgers researchers that is trying to understand the earliest evolution of these processes, and we think that hydrogen was probably one of the most abundant gases in the early Earth that supported life.

    What are the chances of life being found elsewhere in our solar system and the universe?

    We’ve been looking for evidence of life on Mars since the Viking mission, which landed in 1976. I think it will be very difficult to prove there is life on Mars today, but there may be signatures of life that existed on Mars in the distant past. Mars certainly had a lot of water on it and had an atmosphere, but that’s all largely gone now. A proposed mission to Europa – an ice-covered moon of Jupiter – is in the planning phase. NASA’s Cassini mission to investigate Titan, a moon of Neptune, revealed liquid methane over what we think is water – very cold, shallow oceans – so there may be life on Titan.

    What are protein nanomachines?

    They are enzymes that physically move. Each time we take a breath, an enzyme in every cell allows you to transfer electrons to oxygen. Enzymes, like all proteins, are made up of amino acids, of which there are 20 that are used in life. Early on, amino acids were delivered to Earth by meteorites, and we think some of these amino acids could have been coupled together and made nanomachines before life began. That’s what we’re looking to see if we can recreate, using the tens of thousands of protein structures in the Protein Data Bank at Rutgers together with our colleagues in the Center for Advanced Biotechnology and Medicine.

    What are the next steps?

    Organizing our research so it is coherent and relevant to the other collaborating teams in the NASA Astrobiology Institute. We want to develop an education and outreach program at Rutgers that leads to an astrobiology minor for undergraduate students and helps inform K-12 schoolchildren about the origins of life on Earth and what we know and don’t know about the potential for life on other planets. We also want to help make Rutgers a center of excellence in this field so future undergraduate and graduate students and faculty will gravitate towards this university to try to understand the evolution and origin of the molecules that derive energy for life.

    See the full article here .

    Follow Rutgers Research here .

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    Rutgers, The State University of New Jersey, is a leading national research university and the state’s preeminent, comprehensive public institution of higher education. Rutgers is dedicated to teaching that meets the highest standards of excellence; to conducting research that breaks new ground; and to providing services, solutions, and clinical care that help individuals and the local, national, and global communities where they live.

    Founded in 1766, Rutgers teaches across the full educational spectrum: preschool to precollege; undergraduate to graduate; postdoctoral fellowships to residencies; and continuing education for professional and personal advancement.

    As a ’67 graduate of University college, second in my class, I am proud to be a member of

    Alpha Sigma Lamda, National Honor Society of non-tradional students.

     
    • stewarthoughblog 1:20 am on June 6, 2018 Permalink | Reply

      I suppose it is inevitable for naturalists to revisit the myths of chemical evolution, Darwin’s “warm little ponds,” OparinHaldane prebiotic soup, Miller-Urey test tube goo, FeS minerals, etc. This may get funding, have some interesting science, but otherwise will offer nothing to the present chaotic mess of naturalist origin of life, OoL, research.
      If they really want to address OoL, then they need to explain the creation of DNA and the homochiral amino acids and pentose sugars required. The 20 amino acids mentioned are exclusively produced through cellular, aka living, functions, never naturalistically. There is no naturalistic process capable of producing all amino acids.
      The propositions in this article are intellectually insulting and scientifically nonsensical.

      Like

      • richardmitnick 12:59 pm on June 6, 2018 Permalink | Reply

        While I respect your opinions, the main reason I posted this was that anything good that happens at Rutgers, my alma mater, I need to jump on. Rutgers is a great research university with a penchant for very poor representation in social media.

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        • stewarthoughblog 11:32 pm on June 6, 2018 Permalink

          Richard, no slight intended against your alma mater, but it is the substance of the article that prompted my comment, which I can only propose was written by someone very uninformed about the pertinent science, or by a fully impregnated naturalistic ideologue, if you know what I mean.. Regards.

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        • richardmitnick 3:13 pm on June 7, 2018 Permalink

          No harm, no foul. I appreciate your continued interest in the blog. I am in a personal war with Rutgers to wake them up to their web compeition like all of the University of California schools, UBC, U Toronto, U Arizona, a bunch of “state” schools in Australia, and the like, all state schools. I am not asking them to to be Harvard, MIT, Caltech, Oxford or Cambridge. I want what I want.

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        • stewarthoughblog 12:31 am on June 8, 2018 Permalink

          Thank you, sounds like a noble cause, best wishes

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