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  • richardmitnick 2:09 pm on September 3, 2019 Permalink | Reply
    Tags: , , , , Cyanobacteria was responsible for the build-up of oxygen in the Earth’s atmosphere and the subsequent Great Oxidation Event about 2.5 billion years ago., If the film of life were replayed from very early days would it come out the same?, Many Worlds, Paleogenomics-the emerging field explores ancient life and ancient Earth by focusing on genetic material from ancient organisms preserved in today’s organisms, The goals are ambitious: To understand both the early evolution and the origins of life as well as to provide a base of knowledge about likely characteristics of potential life on other planets., The molecular clock is figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged., They ask the question of whether and how the expression of those genes — all important biomolecules generally involved in allowing a cell to operate smoothly — has changed over the eons., We build on modern biology- the existing genes- and use what we know from them to construct a molecular tree of life and come up with the ancestral genes of currently existing proteins., What we do is treat DNA as a fossil a vehicle to travel back in time   

    From Many Worlds: “Exploring Early Earth by Using DNA As A Fossil” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    September 3, 2019
    Marc Kaufman

    1
    Betül Kaçar is an assistant professor at the University of Arizona, and a pioneer in the field of paleogenomics — using genetic material to dive back deep into the ancestry of important compounds. (University of Arizona)

    Paleontology has for centuries worked to understand the distant past by digging up fossilized remains and analyzing how and why they fit into the evolutionary picture. The results have been impressive.

    But they have been limited. The evolutionary picture painted relies largely on the discovery of once hard-bodied organisms, with a smattering of iconic finds of soft-bodied creatures.

    In recent years, however, a new approach to understanding the biological evolution of life has evolved under the umbrella discipline of paleogenomics. The emerging field explores ancient life and ancient Earth by focusing on genetic material from ancient organisms preserved in today’s organisms.

    These genes can be studied on their own or can be synthetically placed into today’s living organisms to see if, and how, they change behavior.

    The goals are ambitious: To help understand both the early evolution and even the origins of life, as well as to provide a base of knowledge about likely characteristics of potential life on other planets or moons.

    “What we do is treat DNA as a fossil, a vehicle to travel back in time,” said Betül Kaçar, an assistant professor at the University of Arizona with more than a decade of experience in the field, often sponsored by the NASA Astrobiology Program and the John Templeton Foundation. “We build on modern biology, the existing genes, and use what we know from them to construct a molecular tree of life and come up with the ancestral genes of currently existing proteins.”

    And then they ask the question of whether and how the expression of those genes — all important biomolecules generally involved in allowing a cell to operate smoothly — has changed over the eons. It’s a variation on one the basic questions of evolution: If the film of life were replayed from very early days, would it come out the same?

    3
    Cyanobacteria, which was responsible for the build-up of oxygen in the Earth’s atmosphere and the subsequent Great Oxidation Event about 2.5 billion years ago. Kaçar studies and replaces key enzymes in the cyanobacteria in her effort to learn how those ancestral proteins may have behaved when compared to the same molecules today.

    The possibility of such research — of taking what is existing today and reconstructing ancient sequences from it — was first proposed by Emile Zuckerkandl, a biologist known for his work in the 1960s with Linus Pauling on the hypothesis of the “molecular clock.” The molecular clock is figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged.

    It would not be until decades later that technology and understandings had reached the point where the ideas could become working science. And as Kaçar makes clear, the effort remains a work in progress.

    Kaçar is perhaps best known for her work on the RuBisCO enzyme, which is present in plant chloroplasts and is involved in fixing atmospheric carbon dioxide during photosynthesis and producing oxygen. Since life’s origins on Earth, enzymes have been the primary mediators of the chemical reactions inside cells that make life as we know it possible.

    This catalyzing of the chemical reaction by which inorganic carbon enters the biological world — processed into sugars and other nutrient-rich compounds — has played an especially central role in the history of life on Earth. It is also often described as the most abundant enzyme on the planet.

    Kaçar and her teams compare RuBisCO (and other) gene sequences from modern organisms to infer what the sequence must have been in their common ancestor. By doing that many, many times, she says, “we follow back the branches of the evolutionary tree”.

    During her time at the NASA Astrobiology Institute as a postdoctoral fellow she developed a system to engineer microbial genomes with synthetic ancient genes [mBio], following the path of that inferred RuBisCO tree of life. The protein-producing gene in the modern genomes of an organism such as cyanobacteria can be replaced with an engineered ancestral gene that would have been present perhaps 2.5 billions of years ago, before the rise of oxygen on our planet.

    Experiments like this were ongoing when I visited her lab in Tucson earlier this year.

    The results: so far, some of the bacteria given the ancestral genes die but some survive while operating more slowly than today’s genes.

    That reduced reaction speed — seemingly related not so much to later mutations but to the amount of the enzyme produced by the engineered genome — may have been a feature of the early RuBisCO enzyme, Kaçar said.

    3
    Scientists trace the points in time where RuBisCO branched out in diverse forms, before and after the Great Oxidation Event. (B. Kaçar)

    The field of paleogenomics, and its search for ancestral forms of important current biomolecules, is growing fast.

    “When I first began this work about 10 years ago, I had to painstakingly explain prior foundational ideas by people like Zuckerkandl, just to introduce the basic concept, because people would say, ‘You wanna do what now?’” Kaçar told me.

    “Today, people are trying this approach across all different areas of biology and this is great news. For example, I just read about a recent effort to reconstruct and resurrect an ancient ferredoxin–a critical enzyme in shuttling electrons around in metabolism. So the idea is now big enough that others are using the same techniques for their own research interests and questions.”

    Kaçar said that her research team has a broad scope. They work on the translation machinery, whereby a cell “reads” the information in a messenger RNA and uses it to build a proteins (which played a crucial role in visualizing the tree of life); on basic metabolism with enzymes like RuBisCO and nitrogenase, and on biosignatures by looking at photosensitive pigments such as rhodopsons.

    “I like that we’re trying to cover many basic biological functions and learning along the way what can or cannot and what ought or ought not be done in developing these techniques.

    “We rolled up our sleeves, we have big dreams, the energy and the time. We hope to get there. We are working to get there.”

    But the work does have challenges. One is that the ancient rock record biosignatures that Kaçar and her colleagues are looking for — generally different carbon isotopes — may not precisely match the biosignatures left by the enzyme with engineered ancestral genes.

    Also, as Kaçar explained, there is little that is “systemically transferable between vastly different ancient molecules.”

    “Each mathematical effort to infer what the ancient sequences of a given gene is its own unique undertaking,” she said, “And the model outputs have to be interpreted on their own basis: i.e., is the signal into the deep past good? how far back does the signal reliably go? what is the probability that the inferred sequence will actually be functional?

    “In turn, each effort to engineer a genome with an inferred ancient component has to be undertaken on its own merits and may have its own difficulties.”

    4
    A graphic presentation of Kaçar’s work in reconstructing ancestral genomes. From a paper authored by Kaçar and colleague Amanda Garcia titled How to resurrect ancestral proteins as proxies for ancient biogeochemistry in Science Direct.

    Kaçar’s work is about as interdisciplinary as could be, bringing together evolutionary biologists and geologists, computer scientists and synthetic biologists, astrobiologists and astronomers. It has also led to her association with, among other organizations, the Earth-Life Science Institute in Tokyo, which focuses on the origins of life.

    The implications for origins of life and molecular evolutionary research are pretty clear, but she wants to take the work with ancestral genes and biomolecules further.

    “I aim to provide insights into the biology of the past and then tie this knowledge to our search for life in the universe,” she said during a recent Public Library of Science (PLOS) interview.

    “A planet free from life today, doesn’t necessary indicate a planet that never hosted life and to understand whether if this was the case, we need to have more than one instance of life to serve as a basis of comparison.

    “Earth’s past provides us alternative scenarios. Travel to about 4 billion years ago, what might greet you is a hot, vigorous planet with giant lava volcanoes, no major continents and lots of meteorite impacts.

    But we think life, with ecologies different from what is familiar to us today, probably existed back then too.” Surprisingly, however, “molecules of these life forms, however, were close to the fundamental molecules of life today.”

    A team at the University of Regensburg in Germany, for instance, found a reconstructed bacteria enzyme they were studying was quite similar to what would have been present 3.4 billion years ago.

    5
    NASA has played a significant role in Kaçar’s life. After graduating from Emory University’s School of Medicine and Chemistry with a PhD in Bio-Molecular Chemistry, she changed her focus to the study of evolution and won a grant from NASA’s Astrobiology Institute. She later won a grant from the NASA Exobiology program. and most recently the NASA Early Career Fellowship.

    Many scientists travel unexpected and intriguing personal paths on the way to their research, and Kaçar is certainly an example of that.

    Her family was initially from the Black Sea region of Turkey, where many women are known to be “gözü kara,” which translates from Turkish, Kaçar said, as having a perhaps unwise state of fearlessness. No women in her family had graduated from high school.

    Kaçar was born in Istanbul. As she remembers well, while in third grade her father sat her down and told her he couldn’t help anymore with her schoolwork because he had left school after second grade. But he encouraged her to get an education and to become an independent (and fearless) person.

    While studying chemistry as an undergraduate at Marmara University in Istanbul, she volunteered to be a real-time translator for a visiting group of scientists who had become to discuss protein biochemistry — especially as it relates to Alzheimer’s and Parkinson’s Diseases.

    One talk in particular fascinated her. It was on the molecular properties of an enzyme whose activity changes with age. She says she will never forget that first time she learned that when the site of a protein changes, entire cellular and bodily activities can collapse.

    She was “hooked” and reached out to one of the American professors who had been in the group. He suggested that she apply for a Howard Hughes Medical Institute summer undergraduate research scholarship, which she did and won one. That brought her to Atlanta and Emory University, where she visited his laboratory to study a particular protein . This was her first time in the U.S. or in a scientific research laboratory. In 2004, I came back to the same laboratory as a graduate student. She was 20 years old and didn’t know anyone outside the lab.

    In the following years she won a NASA research grant, taught and researched at Harvard University, won her current position at UA and, last year gave birth to a son. Kaçar is an accomplished public speaker as well, dedicated to bringing science to people.

    And all the while, she is working to solve major scientific problems in a burgeoning but exacting discipline.

    “I am not afraid of failure,” she said. “For better or for worse, I am “gözü kara” [fearless].‘

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 2:04 pm on August 1, 2019 Permalink | Reply
    Tags: , Many Worlds,   

    From Many Worlds: “Exoplanets Discoveries Flood in From TESS” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    August 1, 2019
    Marc Kaufman

    1
    NASA’s Transiting Exoplanet Survey Satellite (TESS) has hundreds of “objects of interest” waiting to be confirmed as planets in the data from the space telescope’s four cameras. These three were the first confirmed TESS discoveries, identified last year during its first three months of observing. By the time the mission is done, TESS’s wide-field cameras will have covered the whole sky in search of transiting exoplanets around 200,000 of the nearest (and brightest) stars. (NASA / MIT / TESS)

    NASA/MIT TESS replaced Kepler in search for exoplanets

    The newest space telescope in the sky–NASA’s Transiting Exoplanet Survey Satellite, TESS — has been searching for exoplanets for less than a year, but already it has quite a collection to its name.

    The TESS mission is to find relatively nearby planets orbiting bright and stable suns, and so expectations were high from the onset about the discovery of important new planets and solar systems. At a meeting this week at the Massachusetts Institute of Technology devoted to TESS results, principal investigator George Ricker pronounced the early verdict.

    The space telescope, he said, “has far exceeded our most optimistic hopes.” The count is up to 21 new planets and 850 additional candidate worlds waiting to be confirmed.

    Equally or perhaps more important is that the planets and solar systems being discovered promise important results. They have not yet included any Earth-sized rocky planet in a sun’s habitable zone — what is generally considered the most likely, though hardly the only, kind of planet to harbor life — but they did include planets that offer a great deal when it comes to atmospheres and how they can be investigated.

    2
    This infographic illustrates key features of the TOI 270 system, located about 73 light-years away in the southern constellation Pictor. The three known planets were discovered by NASA’s Transiting Exoplanet Survey Satellite through periodic dips in starlight caused by each orbiting world. Insets show information about the planets, including their relative sizes, and how they compare to Earth. Temperatures given for TOI 270’s planets are equilibrium temperatures, (NASA’s Goddard Space Flight Center/Scott Wiessinger)

    One of the newest three-planet system is called TOI-270, and it’s about 75 light years from Earth. The star at the center of the system is a red dwarf, a bit less than half the size of the sun.

    Despite its small size, it’s brighter than most of the nearby stars we know host planets. And it’s stable, making its solar system especially valuable. When variations in the star’s light are minimal, and they’re less likely to get in the way of trying to pick up subtle changes caused by its orbiting planets.

    While none of the three planets are likely habitable, more planets may yet be found farther out in the star system, orbiting in more habitable orbits. A paper describing the system was published in the journal Nature Astronomy.

    “This system is exactly what TESS was designed to find — small, temperate planets that pass, or transit, in front of an inactive host star, one lacking excessive stellar activity, such as flares,” said lead researcher Maximilian Günther, a Torres Postdoctoral Fellow at the (MIT) Kavli Institute for Astrophysics and Space Research in Cambridge.

    “This star is quiet and very close to us, and therefore much brighter than the host stars of comparable systems. With extended follow-up observations, we’ll soon be able to determine the make-up of these worlds, establish if atmospheres are present and what gases they contain, and more.”

    This is essential both in terms of understand the particular planet, and in developing methods for reading the atmospheres of exoplanets more generally. Those readings will hopefully some day tell researchers that they have found a planet with an atmosphere out of chemical balance in ways that could only be the result of biology.

    The authors estimate that the James Webb Space Telescope, now scheduled to launch in 2021, will eventually have a view of the system for over half the year, and it should be able to pick out the atmospheric signals for both planets.

    NASA/ESA/CSA Webb Telescope annotated

    As explained in a NASA release, the innermost planet, TOI 270 b, is likely a rocky world about 25% larger than Earth. It orbits the star every 3.4 days at a distance about 13 times closer than Mercury orbits the sun. Based on statistical studies of known exoplanets of similar size, the science team estimates TOI 270 b has a mass around 1.9 times greater than Earth’s.

    Due to its proximity to the star, planet b is an scalding-hot world. Its equilibrium temperature — that is, the temperature based only on energy it receives from the star, which ignores additional warming effects from a possible atmosphere — is around 490 degrees Fahrenheit (254 degrees Celsius).

    The other two planets, TOI 270 c and d, are, respectively, 2.4 and 2.1 times larger than Earth and orbit the star every 5.7 and 11.4 days. Although only about half its size, both may be similar to Neptune in our solar system, with compositions dominated by gases rather than rock. They likely weigh around 7 and 5 times Earth’s mass, respectively.

    All of the planets are expected to be tidally locked to the star, which means they only rotate once every orbit and keep the same side facing the star at all times, just as the Moon does in its orbit around Earth.

    Planet c and d might best be described as mini-Neptunes, a type of planet not seen in our own solar system. The researchers hope further exploration of TOI 270 may help explain how two of these mini-Neptunes formed alongside a nearly Earth-size world.

    “An interesting aspect of this system is that its planets straddle a well-established gap in known planetary sizes,” said co-author Fran Pozuelos, a postdoctoral researcher at the University of Liège in Belgium.

    “It is uncommon for planets to have sizes between 1.5 and two times that of Earth for reasons likely related to the way planets form, but this is still a highly controversial topic. TOI 270 is an excellent laboratory for studying the margins of this gap and will help us better understand how planetary systems form and evolve.”

    4
    Only 31 light-years away from Earth, the exoplanet GJ 357 d catches light from its host star GJ 357, in this artistic rendering.

    And then there’s the planetary system of GJ 357.

    The newly discovered planets orbit an M-type dwarf about one-third the sun’s mass and size and about 40% cooler that our star. The system is located 31 light-years away, which makes it a relatively close neighbor.

    In February, TESS cameras caught the star dimming slightly every 3.9 days, revealing the presence of a transiting exoplanet that passes across the face of its star during every orbit and briefly dims the star’s light. That discovery led to the finding of two more planets [Astronomy and Astrophysics] around the star, including one that may be quite promising.

    “In a way, these planets were hiding in measurements made at numerous observatories over many years,” said Rafael Luque, a doctoral student at the Institute of Astrophysics of the Canary Islands (IAC) on Tenerife, who led the discovery team.

    6
    IAC

    “It took TESS to point us to an interesting star where we could uncover them.”

    But while researchers were looking at ground-based data to confirm the existence of the hot Earth, they uncovered two additional worlds. The farthest-known planet, named GJ 357 d, is the one that really caught their attention.

    “GJ 357 d is located within the outer edge of its star’s habitable zone, where it receives about the same amount of stellar energy from its star as Mars does from the sun,” said co-author Diana Kossakowski at the Max Planck Institute for Astronomy in Heidelberg, Germany.


    Max Planck Institute for Astronomy campus, Heidelberg, Baden-Württemberg, Germany

    “If the planet has a dense atmosphere, which will take future studies to determine, it could trap enough heat to warm the planet and allow liquid water on its surface.”

    This GJ 357 system illustrates well how exoplanet discoveries are gathered, confirmed and then interpreted.

    8
    Transit data are rich with information. By measuring the depth of the dip in brightness and knowing the size of the star, scientists can determine the size or radius of the planet. The orbital period of the planet can be determined by measuring the elapsed time between transits. Once the orbital period is known, Kepler’s Third Law of Planetary Motion can be applied to determine the average distance of the planet from its stars. (NASA Ames)

    A planet orbiting GJ 357 was first identified via the transit method by TESS. Then it was confirmed using the ground-based radial velocity data collected from numerous ground-based telescopes over the years. That data was recoded and re-interpeted (with the assistance of the Carnegie Institution’s Paul Butler (who was part of the team that confirmed the detection of the first exoplanet in 1995) and the additional two planets were identified.

    9
    This artist’s illustration demonstrates the “wobble,” or radial velocity, technique for finding planets. The planet-detection technique relies on the fact that stars wobble back and forth as their planets circle around, tugging on them with their gravity. As a star moves toward us, the color of its light shifts to shorter, or bluer, wavelengths. As the star heads away, its light stretches into longer, or redder, wavelengths. The same principle, called the Doppler effect, causes sound from a speeding train to lower in pitch as it passes by.
    By measuring changes in the wavelength of light from a star, astronomers can track changes in the star’s velocity that arise from circling planets. By measuring the speed of the star and the period of the wobble, they can determine the mass and distance of the unseen planet, respectively. (NASA)

    Then the information was put through models by an interdisciplinary team and this announcement was the result:

    “An international team of astronomers… has characterized the first potentially habitable world outside of our own solar system.” The paper appeared in the journal Astrophysical Journal Letters.

    “This is exciting, as this is humanity’s first nearby super-Earth that could harbor life – uncovered with help from TESS, our small, mighty mission with a huge reach,” said Lisa Kaltenegger, associate professor of astronomy, director of Cornell’s Carl Sagan Institute and a member of the TESS science team.

    The exoplanet is more massive than our planet, and Kaltenegger said the discovery will provide insight into Earth’s heavyweight planetary cousins. “With a thick atmosphere, the planet GJ 357 d could maintain liquid water on its surface like Earth, and we could pick out signs of life with telescopes that will soon be online,” she said.

    How did Kaltenegger and her colleagues get to that conclusion?

    The planet receives little more than a third of the radiation that Earth receives, making it similar to Mars. If the planet released gases present since its formation at a rate similar to Earth, the surface temperature would remain below freezing.

    But as their paper concludes:

    “Geological active worlds, like our Earth, are expected to build up CO2 concentrations due to the feedback of the carbonate-silicate cycle. We model atmospheres (with and without oxygen) as three examples, where we increase CO2 concentration so that the planet’s average surface temperature is above freezing.”

    “The sample reflection, emission and transmission spectra show features of a wide range of chemicals — water, carbon dioxide, methane, ozone and oxygen for Earth-like atmospheres from the Visible to Infrared wavelength — which would indicate habitability for observations with upcoming telescopes.”

    This is how the exoplanet drama works. Each significant discovery makes possible a future discovery, then additional hypotheses are put forward that often need new and more powerful viewing telescopes to prove or disprove. There are many goals in this enterprise, but the big one is clearly the discovery of clear signs of life far beyond Earth.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

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

    1
    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.

    2
    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.

    4
    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.

    6
    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.

    6
    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 .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 4:40 pm on June 24, 2019 Permalink | Reply
    Tags: "The Interiors of Exoplanets May Well Hold the Key to Their Habitability", , , “The heart of habitability is in planetary interiors” concluded Carnegie geochemist George Cody, , Cosmochemistry, , Deep Carbon Observatory’s Biology Meets Subduction project, Findings from the Curiosity rover that high levels of the gas methane had recently been detected on Mars., , Many Worlds, PREM-Preliminary Reference Earth Model, This idea that subsurface life on distant planets could be identified by their byproducts in the atmosphere has just taken on a new immediacy, We’ve only understood the Earth’s structure for the past hundred years.   

    From Many Worlds: “The Interiors of Exoplanets May Well Hold the Key to Their Habitability” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    June 23, 2019
    Marc Kaufman

    1
    Scientists have had a working — and evolving — understanding of the interior of the Earth for only a century or so. But determining whether a distant planet is truly habitable may require an understanding of its inner dynamics — which will for sure be a challenge to achieve. (Harvard-Smithsonian Center for Astrophysics)

    The quest to find habitable — and perhaps inhabited — planets and moons beyond Earth focuses largely on their location in a solar system and the nature of its host star, the eccentricity of its orbit, its size and rockiness, and the chemical composition of its atmosphere, assuming that it has one.

    Astronomy, astrophysics, cosmochemistry and many other disciplines have made significant progress in characterizing at least some of the billions of exoplanets out there, although measuring the chemical makeup of atmospheres remains a immature field.

    But what if these basic characteristics aren’t sufficient to answer necessary questions about whether a planet is habitable? What if more information — and even more difficult to collect information — is needed?

    That’s the position of many planetary scientists who argue that the dynamics of a planet’s interior are essential to understand its habitability.

    With our existing capabilities, observing an exoplanet’s atmospheric composition will clearly be the first way to search for signatures of life elsewhere. But four scientists at the Carnegie Institution of Science — Anat Shahar, Peter Driscoll, Alycia Weinberger, and George Cody — argued in a recent perspective article in Science 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.

    They argue that on Earth, for instance, plate tectonics are crucial for maintaining a surface climate where life can fill every niche. And without the cycling of material between the planet’s 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.

    1
    What makes a planet potentially habitable and what are signs that it is not. This graphic from the Carnegie paper illustrates the differences (Shahar et al.)

    “The perspective was our way to remind people that the only exoplanet observable right now is the atmosphere, but that the atmospheric composition is very much linked to planetary interiors and their evolution,” said lead author Shahar, who is trained in geological sciences. “If there is a hope to one day look for a biosignature, it is crucial we understand all the ways that interiors can influence the atmospheric composition so that the observations can then be better understood.”

    “We need a better understanding of how a planet’s composition and interior influence its habitability, starting with Earth,” she 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, defining factors such 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,” Carnegie planetary scientist Peter Driscoll explained in a release.

    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 Carnegie geochemist George Cody.

    Our knowledge of the Earth’s interior starts with these basic contours: it has a thin outer crust, a thick mantle, and a core the size of Mars. A basic question that can be asked and to some extent answered now is whether this structure is universal for small rocky planets. Will these three layers be present in some form in many other rocky planets as well?

    Earlier preliminary research published in the The Astrophysical Journal suggests that the answer is yes – they will have interiors very similar to Earth.

    “We wanted to see how Earth-like these rocky planets are. It turns out they are very Earth-like,” said lead author Li Zeng of the Harvard-Smithsonian Center for Astrophysics (CfA)

    To reach this conclusion Zeng and his co-authors applied a computer model known as the Preliminary Reference Earth Model (PREM), which is the standard model for Earth’s interior. They adjusted it to accommodate different masses and compositions, and applied it to six known rocky exoplanets with well-measured masses and physical sizes.

    They found that the other planets, despite their differences from Earth, all should have a nickel/iron core containing about 30 percent of the planet’s mass. In comparison, about a third of the Earth’s mass is in its core. The remainder of each planet would be mantle and crust, just as with Earth.

    “We’ve only understood the Earth’s structure for the past hundred years. Now we can calculate the structures of planets orbiting other stars, even though we can’t visit them,” adds Zeng.

    The model assumes that distant exoplanets have chemical compositions similar to Earth. This is reasonable based on the relevant abundances of key chemical elements like iron, magnesium, silicon, and oxygen in nearby systems. However, planets forming in more or less metal-rich regions of the galaxy could show different interior structures.

    While thinking about exoplanetary interiors—and some day finding ways to investigate them — is intriguing and important, it’s also apparent that there’s a lot more to learn about role of the Earth’s interior in making the planet habitable.

    In 2017, for instance, an interdisciplinary group of early career scientists visited Costa Rica’s subduction zone, (where the ocean floor sinks beneath the continent) to find out if subterranean microbes can affect geological processes that move carbon from Earth’s surface into the deep interior.

    3
    Donato Giovannelli and Karen Lloyd collect samples from the crater lake in Poás Volcano in Costa Rica. (Katie Pratt)

    The study shows that microbes consume and trap a small but measurable amount of the carbon sinking into the trench off Costa Rica’s Pacific coast. The microbes may also be involved in chemical processes that pull out even more carbon, leaving cement-like veins of calcite in the crust.

    According to their new study in Nature, the answer is yes.

    In all, microbes and calcite precipitation combine to trap about 94 percent of the carbon squeezed out from the edge of the oceanic plate as it sinks into the mantle during subduction. This carbon remains naturally sequestered in the crust, where it cannot escape back to the surface through nearby volcanoes in the way that much carbon ultimately recycles.

    These unexpected findings have important implications for how much carbon moves from Earth’s surface into the interior, especially over geological timescales. The research is part of the Deep Carbon Observatory’s Biology Meets Subduction project.

    Overall, the study shows that biology has the power to affect carbon recycling and thereby deep Earth geology.

    “We already knew that microbes altered geological processes when they first began producing oxygen from photosynthesis,” said Donato Giovannelli of University of Naples, Italy (and who I knew from time spent at the Earth-Life Science Institute Tokyo.) He is a specialist in extreme environments and researches what they can tell us about early Earth and possibly other planets.

    “I think there are probably even more ways that biology has had an outsized impact on geology, we just haven’t discovered them yet.”

    The findings also shows, Giovanelli told me, that subsurface microbes might have a similarly outsized effect on the composition and balancing of atmospheres—“hinting to the possibility of detecting the indirect effect of subsurface life through atmosphere measurements of exoplanets,” he said.

    5
    The 2003 finding by Michael Mumma and Geronimo Villanueva of NASA Goddard Space Flight Center showing signs of major plumes of methane on Mars. While some limited and seasonably determined concentrations of methane have been detected since, there has been nothing to compare with the earlier high methane readings Mars — until just last week. (NASA/ M. Mumma et al)

    This idea that subsurface life on distant planets could be identified by their byproducts in the atmosphere has just taken on a new immediacy with findings from the Curiosity rover that high levels of the gas methane had recently been detected on Mars. Earlier research had suggested that Mars had some subsurface methane, but the amount appeared to be quite minimal — except as detected once back in 2003 by NASA scientists.

    None of the researchers now or in the past have claimed that they know the origin of the methane — whether it is produced biologically or through other planetary processes. But on Earth, some 90 percent of methane comes from biology — bacteria, plants, animals.

    Could, then, these methane plumes be a sign that life exists (or existed) below the surface of Mars? It’s possible, and highlights the great importance of what goes on below the surface of planets and moons.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 12:50 pm on May 28, 2019 Permalink | Reply
    Tags: "The Message of Really, “Kimberley” formation of Gale Crater on Mars taken by NASA’s Curiosity rover, Ethiopia’s Danakil Depression, , Many Worlds, Really Extreme Life"   

    From Many Worlds: “The Message of Really, Really Extreme Life” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    May 28, 2019
    Marc Kaufman

    1
    Hydrothermal system at Ethiopia’s Danakil Depression, where uniquely extreme life has been found in salt chimneys and surrounding water. The yellow deposits are a variety of sulphates and the red areas are deposits of iron oxides. Copper salts color the water green. (Felipe Gomez/Europlanet 2020 RI)

    Ethiopia’s Dallol volcano and hot springs have created an environment about as hostile to life as can be imagined.

    Temperatures in the supersaturated water reach more than 200 degrees F (94 C) and are reported to approach pure acidity, with an extraordinarily low pH of 0.25. The environment is also highly salty, with salt chimneys common.

    Yet researchers have just reported finding ultra-small bacteria living in one of the acidic, super-hot salt chimneys. The bacteria are tiny — up to 20 times smaller than the average bacteria — but they are alive and in their own way thriving.

    In the world of extremophiles, these nanohaloarchaeles order bacteria are certainly on the very edge of comprehension. But much the same can be said of organisms that can withstand massive doses of radiation, that survive deep below the Earth’s surface with no hint of life support from the sun and its creations, that keep alive deep in glacier ice and even floating high in the atmosphere. And as we know, spacecraft have to be well sterilized because bacteria (in hibernation) aboard can survive the trip to the moon or Mars.

    Not life it is generally understood. But the myriad extremophiles found around the globe in recent decades have brought home the reality that we really don’t know where and how life can survive; indeed, these extremophiles often need their conditions to be super-severe to succeed.

    And that’s what makes them so important for the search for life beyond Earth. They are proof of concept that some life may well need planetary and atmospheric conditions that would have been considered utterly uninhabitable not long ago.

    2
    Montage from the Dallol site: (A) the sampling site, (B) the small chimneys (temperature of water 90 ºC. (C) D9 sample from a small chimney in (A). (D-L) Scanning Electron Microscope and (M-O) Scanning Transmission Electron Microscope images of sample D9 showing the morphologies of ultra-small microorganisms entombed in the mineral layers. (Gomez et al/Europlanet 2020 Research Infrastructure)

    The unusual and extreme life and geochemistry of Dallol has been studied by a team led by Felipe Gómez from Astrobiology Center in Spain.

    The samples were collected during a field trip to the Dallol volcano and the Danakil Depression in northern Ethiopia in January 2017, which was funded by the Europlanet 2020 Research Infrastructure (RI). The results were published this week in the journal, Scientific Reports.

    The area is consistently one of the hottest in the world, both because of its near-equatorial location, the Dallol volcano and hot springs, and that much of it is below sea level.

    Its psychedelic appearance comes from the condensation of superheated water saturated with various salts, including silver chloride, zinc iron sulphide, manganese dioxide and normal rock-salt.

    The team collected samples of the thin layers of salt deposits from the wall of a yellow chimney stack and a bluish pool of water surrounding the outcrop (above.)

    The samples were brought in sterile, sealed vials to state-of-the-art facilities in Spain, where they were analyzed using a range of techniques, including electron microscopy, chemical analysis and DNA sequencing.

    The team identified tiny, spherical structures within the salt samples that had a high carbon content, demonstrating an unambiguously biological origin.

    “This is an exotic, multi-extreme environment, with organisms that need to love high temperature, high salt content and very low pH in order to survive,” Gómez said. And love it they do, raising the most interesting question of whether they adapted to the conditions or emerged from them.

    Just last month, the same international team published a review in the journal Astrobiology describing the close parallels between the Dallol area and the hydrothermal environments found on Mars — including the Gusev Crater, where NASA’s Spirit Mars Exploration Rover landed in .

    As is the norm in the effort to understand life in extreme conditions and astrobiology generally, they focused on the geology and geochemistry of the site that gave rise to the extreme life.

    “The physical and compositional features of the Dallol deposits, their mineralogies, sedimentary and alteration features, and their location in a region of basaltic volcanism of planetary-scale importance, are testament to the novelty of this extreme environment and its ability to host life-forms and to preserve biosignatures,” they wrote.

    “It is therefore also a reliable analog to ancient martian environments and habitats. Deep investigation of the characteristics of this unique geological site will improve our understanding of the limits of life on Earth and inform the search for life on Mars.”

    3
    A view from the “Kimberley” formation of Gale Crater on Mars taken by NASA’s Curiosity rover. The mission has confirmed the long-ago presence of large amounts of water on the planet, as well as organic compounds needed for life. Curiosity was not equipped to be a life detection mission, but the follow-up Mars 2020 rover mission will be. The colors are adjusted so that rocks look approximately as they would if they were on Earth, to help geologists interpret the rocks. day, or sol, of the mission. (NASA/JPL-Caltech/MSSS)

    While this summation is surely accurate, it is also true that findings like these tell a larger story that goes well beyond Mars. Because the discovery of such a vast number and variety of extremophiles on Earth is one of the key factors that has led many space scientists and astrobiologists to conclude that life beyond Earth is likely.

    If life can survive such unusual and extreme conditions on Earth, logic says that this flexibility would no doubt be present on other potentially habitable planets and moons.

    Other major factors pointing to the plausibility of life beyond Earth are now broadly accepted:

    We now know there are billions upon billions of stars in our own Milky Way galaxy, and that most of them have planets orbiting them. The Kepler Space Telescope was crucial to reaching that consensus through its survey of one small bit of the distant sky.
    The most common planets are small and rocky ones, and some of them are within the habitable zones of their host star. This means the planet can at least sometimes support liquid water; in other words that it is neither too hot (close to its star) or too cold (far from its star.) Liquid water is considered to be essential to assemble and support life.
    The physics and chemistry of the cosmos appear to be consistent with what exists on Earth.

    None of this means any particular planet will support life since there are many other factors at play, such as how circular or elliptical the planet’s orbit might be, as well as the presence and composition of an atmosphere and a protective magnetic field. But our increasingly better understanding of exoplanets, solar systems and extreme life has brought legions of scientists into that hunt for extraterrestrial life — and they have found many ways to move forward as well as to avoid errors.

    3
    An overview of the past, present, and future of research on remotely detectable biosignatures from an Astrobiology journal paper by NASA NExSS participants. Research historically has focused on cataloguing lists of substances or physical features that yield spectral signatures as indicators of potential life on exoplanets. Recent progress has led to an understanding of how environmental context is critical to interpret signatures of nonliving planets that may mimic some effects of biota. Exoplanet observing telescopes in the near future hold promise to provide direct spectral imaging that can chemically characterize rocky planets in the habitable zone of their parent star. Anticipating these capabilities, the field should seek to develop frameworks to utilize widespread but sparse data to deliver quantitative assessments of whether or not a given planet has life. (Aaron Gronstal)

    While the Dallol discoveries (and others like them) are encouraging, they are sobering as well. Finding these creatures here on Earth has been very difficult, so imagine how challenging it will be to detect the presence of comparable microbial life on now desiccated Mars or a distant planet.

    Indeed, it would be impossible because their small numbers and limited metabolism don’t provide enough of a chemical biosignature to be detected even by telescopes and spectrographs a million times more powerful than what we have now. In terms of exoplanets, what is needed is a planet where plentiful life is providing a strong global biosignature of some kind.

    That ups the ante quite a bit in the search for life beyond Earth. But there are a vast multitude of planets out there, and a logic to the possibility that some have enough life on them for us to some day detect it.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 10:02 am on May 13, 2019 Permalink | Reply
    Tags: , , Many Worlds, NASA’s Astrobiology Program, NExSS 2.0, Nexus for Exoplanet System Science or “NExSS”, Signatures of life on distant planets, Teams from seventeen academic and NASA centers   

    From Many Worlds: “NExSS 2.0” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    May 13, 2019
    Marc Kaufman

    1
    Finding new worlds can be an individual effort, a team effort, an institutional effort. The same can be said for characterizing exoplanets and understanding how they are affected by their suns and other planets in their solar systems. When it comes to the search for possible life on exoplanets, the questions and challenges are too great for anything but a community. NASA’s NExSS initiative has been an effort to help organize, cross-fertilize and promote that community. This artist’s concept Kepler-47, the first two-star systems with multiple planets orbiting the two suns, suggests just how difficult the road ahead will be. ( NASA/JPL-Caltech/T. Pyle)

    The Nexus for Exoplanet System Science, or “NExSS,” began four years ago as a NASA initiative to bring together a wide range of scientists involved generally in the search for life on planets outside our solar system.

    With teams from seventeen academic and NASA centers, NExSS was founded on the conviction that this search needed scientists from a range of disciplines working in collaboration to address the basic questions of the fast-growing field.

    Among the key goals: to investigate just how different, or how similar, different exoplanets are from each other; to determine what components are present on particular exoplanets and especially in their atmospheres (if they have one); to learn how the stars and neighboring exoplanets interact to support (or not support) the potential of life; to better understand how the initial formation of planets affects habitability, and what role climate plays as well.

    Then there’s the question that all the others feed in to: what might scientists look for in terms of signatures of life on distant planets?

    Not questions that can be answered alone by the often “stove-piped” science disciplines — where a scientist knows his or her astrophysics or geology or geochemistry very well, but is uncomfortable and unschooled in how other disciplines might be essential to understanding the big questions of exoplanets.

    2
    The original NExSS team was selected from groups that had won NASA grants and might want to collaborate with other scientists with overlapping interests and goals but often from different disciplines. (NASA)

    The original idea for this kind of interdisciplinary group came out of NASA’s Astrobiology Program, and especially from NASA astrobiology director Mary Voytek and colleague Shawn Domogal-Goldman. It was something of a gamble, since scientists who joined would essentially volunteer their time and work and would be asked to collaborate with other scientists in often new ways.

    But over the past four years NExSS has proven itself to be very active and useful in terms of laying out strategies for tackling the biggest questions in the field of exoplanets and whether they might harbor life. In two major reports last year, the private, congressionally-mandated National Academies of Sciences, Engineering and Medicine held up NExSS as a successful model for moving the science forward.

    One of the study co-chairs, David Charbonneau of Harvard University, said after the release of the study that the “promise of NExSS is tremendous…We really want that idea to grow and have a huge impact.”

    3
    This major report from the National Academy of Sciences last year endorsed NExSS as a program that substantially aided the exoplanet community. The report recommended that the organization be expanded. (NAS)

    So with that kind of affirmation, it was hardly surprising that the first gathering of a newly constituted NExSS at the University of California, Santa Cruz featured 34 teams, double the original 17. (The team members, both new and original, are here.)

    As explained at the opening of the gathering by Voytek and others, the NExSS approach is all about creating, expanding and promoting the fast-growing fields of exoplanet habitability and astrobiology more generally.

    “The original NExSS members were in service to all of you,” she told the group. “They provided the opportunity to help your community to push questions further and also to get NASA headquarters to give some necessary attention to what you are doing.”

    And in many ways they succeeded. The NExSS teams may not have gotten funded additionally for their work, but the group’s rising profile created important advisory opportunities for participants.

    From the first NExSS groups, for instance, scientists were selected for leadership roles in the main exoplanet science group and several for science and technology definition teams. These groups established by NASA are putting together four proposals for a grand observatory for the 2030s — a hoped-for successor to the Hubble Space Telescope and the James Webb Space Telescope.

    NExSS members also were called on to organize in-depth workshops on subjects ranging from defining and interpreting biosignatures on distant planets, to the centrality of exoplanet interiors and most recently to what signs of advanced technological civilizations might be detectable. Major white papers were generally written, submitted and published in journals following these NExSS workshops.

    “I think putting together NExSS is most successful thing I’ve done in my career in NASA,” said Voytek who, in her decade-plus at the agency, has worked to change attitudes about astrobiology and interdisciplinary work. “I’m proud of what you did and we did.”

    What’s more, as Voytek explained at the beginning of the meeting, the NExSS approach will spread with the creation of four new networking groups based on the model of NExSS.

    They will use the same cross-disciplinary, get-to-know-your-fellow scientists approach to jump-start collaborations and cross-fertilizing in other aspects of the search for life beyond Earth, as well as the effort to understand how life on Earth (and potentially elsewhere) might have started and grown more complex.

    (The four, below, focus on planetary chemistry before life, on biosignatures, on the transition from early single cell organisms to more complex ones, and on what can be learned from ocean worlds.)

    This expansion, which will be part of a reorganization of NASA’s astrobiology program, will change the way that science teams will be funded and also, as Voytek put it, would “democratize” the process that NExSS began. The original program had selected many of its principal investigators from large teams and organizations, but the expanded NExSS and the four other groups to come will be more widely open to teams and individuals from smaller institutions who are earlier in their careers.

    This is important, Voytek and other NExSS organizers said, because the NExSS approach allows scientists to network in ways that create science opportunities, as well as those avenues into the major prioritizing organizations in their exoplanet/astrobiology community writ large.

    3

    One value of this approach can be seen in the person of planetary scientist Sarah Morrison, a postdoc at the large Pennsylvania State University exoplanet program who has been hired to teach at the much smaller Missouri State University program.

    3

    She is a co-principal investigator on one of two NExSS teams at Penn State and was at last week’s Santa Cruz meeting in that capacity.

    Her research focuses on protoplanetary disks and planet formation within them. In particular, she studies the many different types of interactions — collisions, migrations, atmosphere losses — that forming planets can have within their natal disks. She is also intrigued by solar systems where the planets orbit in resonance to each other.

    These factors, and many others, have implications for the composition of planets and then for the possibility of life starting on them. Factors such as the eccentricity of a planet’s orbit or where it was formed within the disk can make a planet a good candidate for habitability or one where life is impossible.

    For Morrison, NExSS is an avenue for keeping her research vibrant.

    “I’m going to a smaller institution, with not so many people doing exoplanets,” she told me. “For me to remain active in the field and work, and to have the collaborators I need to open possibilities for students working with me, this type of network can be very important – on the research side and education side.”

    She said that it isn’t always easy to find scientists whose work overlaps with hers, but that at the NExSS meeting it was easy.

    “I can definitely see projects down the line as a result of conversations I had with those folks,” she said. “And developing collaborations now is very important to me.”

    As described by Voytek and other NExSS leaders, another major focus of the group has been to encourage NASA headquarters to embrace some of the interdisciplinary approach they practice and are convinced is necessary.

    This is part of a much longer effort by Voytek and other to include the search for life beyond Earth in the missions large and small that NASA develops. There was certainly resistance at times, but the agency has, in the past decade, made that search an increasingly central NASA goal.

    As described by NExSS leader (or “Jedi”) Dawn Gelino, deputy director of the agency’s Exoplanet Science Institute, NASA headquarters has responded in other ways as well, and in recent months made two of its major research grant programs interdivisional.

    That means scientists from quite different but nonetheless related disciplines can — for the first time — together propose projects for funding by those NASA programs. Thomas Zurbuchen, NASA’s associate administrator of the Science Mission Directorate, has been forceful in his support for this kind of approach.

    “As a result of NExSS, we are definitely making a difference at headquarters in terms of the structure of teams responding to calls for proposals,” Gelino said.

    A NExSS interdisciplinary approach is not for everyone, and some question its value. Many researchers would prefer to spend their time at the telescope, in the lab, with their modeling computers, writing papers — with laser focus on their areas of expertise. NExSS leaders regularly make the point that those decisions are understood and perfectly fine.

    But especially in inherently interdisciplinary fields such as exoplanets and astrobiology, the pool of scientists willing to pitch in to advance the community appears to be large and has proven go be quite useful.

    (Since I am writing about NExSS, I want to be clear in saying that the program helps support Many Worlds. A second column about NExSS brain-storming about the future of exoplanet and habitability studies will be coming soon.)

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 11:37 am on March 4, 2019 Permalink | Reply
    Tags: "How Creatures End Up Miles Below the Surface of Earth and Maybe Mars Too", An inevitable and most interesting question that arises is this: If there was robust and adaptable life on early Mars might it have been transported underground in water too?, At the Kopanang mine they had found the roundworm Poikilolaimus oxycercusin in water about a mile underground. What appeared to be the same nematode was also collected from the the Vaal river a few mi, “M. parvella does not have a hibernation stage and cannot survive in fresh water thus it must have been and must be in brackish water all the time” Borgonie said. “The question is did this happe, , , Ecosystems can survive in scalding temperatures in the absence of sunlight at high pressure and without oxygen. Yet they have been found as far down as almost three miles below the surface though in f, H. mephisto, Many Worlds, , Recent reports of another nematode species unaffiliated with South African mines suggests just how robust and adaptable individuals can be — in this case regarding deep freeze hibernation., Round worm Poikilolaimus oxycercus, Salese and colleagues explored 24 deep enclosed craters in the northern hemisphere of Mars with floors lying roughly 4000 meters (2.5 miles) below Martian ‘sea level’ (a level that given the plane, Some potential early Martian life could have migrated into the more protected depths is often discussed as a plausible if at this point untestable possibility   

    From Many Worlds: “How Creatures End Up Miles Below the Surface of Earth, and Maybe Mars Too” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    2019-03-04
    Marc Kaufman

    1
    Poikilolaimus oxycercus is a microscopic nematode, or roundworm, found alive and well more than a mile below the surface in South Africa, where its ancestors had lived for hundreds or thousands of years. (Gaetan Borgonie)

    When scientists speculate about possible life on Mars, they generally speak of microbial or other simple creatures living deep below the irradiated and desiccated surface. While Mars long ago had a substantial period that was wetter and warmer when it also had a far more protective atmosphere, the surface now is considered to be lethal.

    But the suggestion that some potential early Martian life could have migrated into the more protected depths is often discussed as a plausible, if at this point untestable possibility. In this scenario, some of that primitive subsurface life might even have survived the eons in their buried, and protected, environments.

    This thinking has gotten some support in the past decade with the discovery of bacteria and nematodes (roundworms) found as far down as three miles below the surface of South Africa, in water dated as being many thousands or millions years old. The lifeforms have been discovered by a team that has regularly gone down into the nation’s super-hot gold and platinum mines to search for life coming out of boreholes in the rock face of deep mine tunnels.

    2
    Borgonie setting up a water collector for a borehole at the Driefontein mine in the Witwatersrand Basin of South Africa. (Courtesy of Borgonie)

    Now a new paper [below] describes not only the discovery of additional deep subsurface life, but also tries to explain how the distant ancestors of the worms and bacteria and algae might have gotten there.

    Their conclusion: many were pulled down when fractures opened in the aftermath of earthquakes and other seismic events. While many lifeforms were swept down, only a small percentage were able to adapt, evolve and thus survive.

    The is how Gaetan Borgonie, lead author of the paper in Scientific Reports, explained it to me via email:

    “After the discovery of multicellular animals in the deep subsurface up to 3.8 km (2.5 miles) in South Africa everyone was baffled and asked the question how did they get that deep? This question more or less haunted us for more than a decade as we were unable to get our head around it.

    “However during the decade as we made more observations of multicellular organisms we captured in borehole water we found that these were nearly all animals associated with fresh water and not the soil. This indicated the passage to the deep was from a fresh water source on the surface and that animals did not crawl all the way down through the topsoil over millennia.”

    This makes sense because the deepest soil inhabitants live at about six feet below the surface, said Borgonie, formerly of the University of Ghent in Belgium and now with ELi, a Belgian nonprofit that studies extreme life. So another route to their deep subterranean homes was necessary.

    3
    One of six hibernating nematodes found in biofilms from a borehole in the Kopanang mine. Four of the six in this “dauer” or survival state were taken, placed in a petri dish and came back to active life. Several were mated with worms of the same Poikilolaimus oxycercus species and the offspring survived. (Gaetan Borgonie)

    Borgonie and his team conducted a variety of tests — seismic, geological, genetic — but one stands out as most conclusive.

    At the Kopanang mine, they had found the roundworm Poikilolaimus oxycercusin in water about a mile underground. What appeared to be the same nematode was also collected from the the Vaal river, a few miles from the mine.

    The two appeared to be genetically similar, but the best test was to see if they could successfully reproduce. And the answer was that they could.

    It was a smoking gun, though not necessarily a common one. Nematodes from other surfaces and subsurfaces were placed together and were not able to produce young that survived. As explained in the Scientific Reports paper, this may be a function of the once companionable subsurface nematodes having adapted to their environment in ways that broke their connections with surface nematodes of the same species.

    While nematodes can hibernate for long periods in what is called their dauer stage, when they wake up they survive for only 20 to 30 days. Their lines, however, can last in the subsurface for those very long periods.

    4
    Tunnels in South Africa’s Beatrix mine close to where H. mephisto was found. The deeper one goes in the mine, the hotter it gets. And yet life survives in the fracture water and other often tiny pockets of liquid. (Gaetan Borgonie)

    The nematodes collected and tested for this most recent article were but a small part of the zoo of creatures that have been collected from deep underground in South Africa’s Witwatersrand Basin. There was also algae, fungi, bacteria, a crustaceans and even a few insects, the paper reports. The bacteria is important for the nematodes in particular because they are a food source.

    These ecosystems survive in scalding temperatures, in the absence of sunlight, at high pressure and without oxygen. Yet they have been found as far down as almost three miles below the surface, though in far more isolated conditions at that depth.

    5
    Borgonie with Esta van Heerden, who helped gain access to South African mines for researchers including Borgonie and Princeton University geomicrobiologist Tullis Onstott more than a decade ago is part of their research team. She is founder of the mine water remediation company iwatersolutions and was formerly a professor with the University of the Free State in Bloemfontein, where she was a specialist in extremophiles. (Courtesy of Borgonie)

    The age of that life is difficult to determine. While methods exist to determine the age of the fracture water, scientists cannot definitively say when the lifeforms arrived. Still, Borgonie reports that the worms found at the Kopanang mine had been present for between 3,000 and 12,000 years, or rather their ancestors had been there.

    Borgonie and his colleagues had earlier discovered the first multicellular creature at great depth, Halicephalobus mephisto, in mine fracture water .6 to 3 miles down. That discovery, announced in 2011, helped establish that the deep subsurface was more able to support life, even complex life, than expected.

    Often the creatures were living in biofilms, loose collections of bacteria and other life held together in the water by secretions that encase them.

    Another aspect of the deep subsurface nematode story involves specimen found in salty stalactites at the Beatrix gold mine. The worms identified, Monhystrella parvella, are associated with salty environments and so the group inferred that the water and creatures may have come from a sea. There were such seas in what is now South Africa, but it was very long ago.

    “M. parvella does not have a hibernation stage and cannot survive in fresh water, thus it must have been and must be in brackish water all the time,” Borgonie said. “The question is did this happen long ago when that area of South Africa was covered by a sea or did it happen via the salt pans surrounding the Beatrix mine?

    “There is no way to know for now. But the fact is and remains that you have a worm in the subsurface in the middle of South Africa that can only survive in salty water.”

    Recent reports of another nematode species, unaffiliated with South African mines, suggests just how robust and adaptable individuals can be — in this case regarding deep freeze hibernation.

    The longest recorded nematode hibernation was 39 years until Russian scientists announced the discovery of frozen nematodes in deep Siberian permafrost. The worms had been asleep for 42,000 and 34,000 years respectively. A Science Alert article raises the possibility of contamination as an issue, but the scientists maintain they took all possible precautions and are convinced the frozen hibernations were as recorded.

    6
    Using an electron microscope, we see the inside of a stalactite in the Beatrix gold mine, about 1 mile below the surface. The nematodes are of the species Monhystrella parvella. (Gaetan Borgonie)

    That the South African deep subsurface life appears now to have come from the surface — via seismic fractures that could bring rushes or trickles of water filled with life many miles down — does have possible implications for Mars. While no signs of early life on Mars have been discovered, research in recent years has proven that the planet once had substantial water and warmer temperatures. In other words, conditions that might be hospitable to life.

    That theory of a once quite watery Mars was taken a significant step further last week in an article in the Journal of Geophysical Research — Planets , which found evidence of an earlier planet-wide groundwater system. Such a system had been predicted before by models, but now there was significant hard evidence that it had indeed existed.

    “Early Mars was a watery world, but as the planet’s climate changed this water retreated below the surface to form pools and ‘groundwater’,” says lead author Francesco Salese of Utrecht University, the Netherlands.

    “We traced this water in our study — as its scale and role is a matter of debate — and we found the first geological evidence of a planet-wide groundwater system on Mars.”

    Salese and colleagues explored 24 deep, enclosed craters in the northern hemisphere of Mars, with floors lying roughly 4000 meters (2.5 miles) below Martian ‘sea level’ (a level that, given the planet’s lack of seas, is arbitrarily defined on Mars based on elevation and atmospheric pressure).

    The scientists found features on the floors of these craters that could only have formed in the presence of water. Many craters contain multiple features, all at depths of 2.5 to 3 miles – indicating that these craters once contained pools and flows of water that changed and receded over time.

    7
    Researchers said flow channels, pool-shaped valleys and fan-shaped sediment deposits seen in dozens of kilometers-deep craters in Mars’ northern hemisphere would have needed water to form. (European Space Agency)

    So an inevitable and most interesting question that arises is this: If there was robust and adaptable life on early Mars, might it have been transported underground in water too?

    The planet does have seismic activity — some are called Marsquakes — that can open fractures. It seems plausible that if life existed in water on the Martian surface, it would have flowed or trickled down fractures and other porous features to substantial depths.

    Given this hypothetical, many would have died but some may have lived and adapted. Rather like what can be seen on Earth in the South African mines.

    With this possibility in mind, the Borgonie paper recommends that the presence of surface fractures be kept in mind when landing sites are chosen on other planets or moons.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 1:28 pm on January 2, 2019 Permalink | Reply
    Tags: , , , , Many Worlds, Weird Planets   

    From Many Worlds: “Weird Planets” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    2019-01-02
    Marc Kaufman

    1
    Artist rendering of an “eyeball world,” where one side of a tidally locked planet is turning hot and the back side is frozen cold. Somewhat like our moon, and very common in the cosmos. But unlike the moon, might some of the the planets be habitable at the edges? (NASA/JPL-Caltech)

    The very first planet detected outside our solar system powerfully made clear that our prior understanding of what planets and solar systems could be like was sorely mistaken.

    51 Pegasi was a Jupiter-like massive gas planet, but it was burning hot rather than freezing cold because it orbited close to its host star — circling in 4.23 days. Given the understandings of the time, its existence was essentially impossible.

    Yet there it was, introducing us to what would become a large and growing menagerie of weird planets.

    Hot Jupiters, water worlds, Tatooine planets orbiting binary stars, diamond worlds (later downgraded to carbon worlds), seven-planet solar systems with planets that all orbit closer than Mercury orbits our sun. And this is really only a brief peak at what’s out there — almost 4,000 exoplanets confirmed but billions upon billions more to find and hopefully characterize.

    I thought it might be useful — and fun — to take a look at some of the unusual planets found to learn what they tell us about planet formation, solar systems and the cosmos.

    2
    Artist’s conception of a hot Jupiter, CoRoT-2a. The first planet discovered beyond our solar system was a hot Jupiter similar to this, and this surprised astronomers and led to the view that many hot Jupiters may exist. That hypothesis has been revised as the Kepler Space Telescope found very few distant hot Jupiters and now astronomers estimate that only about 1 percent of planets are hot Jupiters. (NASA/Ames/JPL-Caltech)

    Let’s start with the seven Trappist-1 planets.

    A size comparison of the planets of the TRAPPIST-1 system, lined up in order of increasing distance from their host star. The planetary surfaces are portrayed with an artist’s impression of their potential surface features, including water, ice, and atmospheres. NASA

    The first three were detected two decades ago, circling a”ultra-cool” red dwarf star a close-by 40 light years away. Observations via the Hubble Space Telescope led astronomers conclude that two of the planets did not have hydrogen-helium envelopes around them, which means the probability increased that the planets are rocky (rather than gaseous) and could potentially hold water on their surfaces.

    Then in 2016 a Belgian team, using the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile, found three more planets, and the solar system got named Trappist-1.

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


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

    The detection of an additional outer planet was announced the next year, and in total three of the seven planets were deemed to be within the host star’s habitable zone — where liquid water could conceivably be present.

    So, we have a most interesting 7-planet solar system quite close to us, and not surprisingly it has become the focus of much observation and analysis.

    But consider this: all seven of those planets orbits Trappist-1 at a distance much smaller than from our sun to the first planet, Mercury. The furthest out planets orbits the star in 19 days, while Mercury orbits in 88 days.

    Given this proximity, then, why are the Trappist-1 planets so interesting, especially in terms of habitability? Because Trappist-1 puts out but .05 percent as much energy as our sun, and the furthest out planet (though very close to the star by the standards of our solar system) is nonetheless likely to be frozen.

    So Trappist-1 a mini-system, with seven tidally-locked (never-rotating) planets that happen to orbit in resonance to each other. Just because it is so different from our system doesn’t mean it isn’t fascinating, instructive, and even possibly the home of planets that could potentially support life.

    And since red dwarf stars are the most common type of star in the Milky way (by lot), red dwarf solar system research is an especially hot field.

    So there are mini planets and systems and massive planets in what used to be considered the impossibly wrong place. And then there are planets with highly eccentric orbits — very different from the largely circular orbits of planets in our system.

    2
    The eccentricity of HD20782b superimposed onto our circular-orbiting inner solar system planets. (Stephen Kane)

    The most extreme eccentric orbit found so far is HD 20782, measured at an eccentricity of .96. This means that the planet moves in a nearly flattened ellipse, traveling a long path far from its star and then making a fast and furious slingshot around the star at its closest approach.

    Many exoplanets have eccentricities far greater than what’s found in our solar system planets but nothing like this most unusual traveler, which has a path seemingly more like a comet than a planet.

    Researchers have concluded that the eccentricity of a planet tends to relate to the number of planets in the system, with many-planeted systems having far more regularly orbiting planets. (Ours and the Trappist-1 system are examples.)

    Unusual planets come in many other categories, such as the chemical makeup of their atmospheres, surfaces and cores. Most of the mass of stars, planets and living things consists of hydrogen and helium, with oxygen, carbon, iron and nitrogen trailing far behind.

    Solid elements are exceptionally rare in the overall scheme of the solar system. Despite being predominant on Earth, they constitute less than 1 percent of the total elements in the solar system, primarily because the amount of gas in the sun and gas giants is so great. What is generally considered the most important of these precious solid elements is iron, which is inferred to be in the core of almost all terrestrial planet.

    The amount of iron or carbon or sulfur or magnesium on or around a planet generally depends on the amount of these “metals” present in the host star, and then in molecular protoplanetary disc remains of the star’s formation. And this is where some of the outliers, the apparent oddities, come in.

    3
    A super-Earth, planet 55 Cancri e, was reported to be the first known planet to have huge layers of diamond, due in part to the high carbon-to-oxygen ratio of its host star. That conclusion has been disputed, but the planet is nonetheless unusual. Above is an artist’s concept of the diamond hypothesis. (Haven Giguere/Yale University)

    The planet 55 Cancri e, for instance, was dubbed a “diamond planet” in 2012 because the amount of carbon relative to oxygen in the star appeared to be quite high. Based on this measurement, a team hypothesized that the surface presence of abundant carbon likely created a graphite surface on the scalding super-Earth, with a layer of diamond beneath it created by the great pressures.

    “This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth,” lead researcher Nikku Madhusudhan of Yale University said in a statement at the time. “The surface of this planet is likely covered in graphite and diamond rather than water and granite.”

    As tends to happen in this early phase of exoplanet characterization, subsequent measurements cast some doubt on the diamond hypothesis. And in 2016, researchers came up with a different scenario — 55 Cancri e was likely covered in lava. But because of heavy cloud and dust cover over the planet, a subsequent group raised doubts about the lava explanation.

    But despite all this back and forth, there is a growing consensus that 55 Cancri e has an atmosphere, which is pretty remarkable given its that its “cold” side has temperatures that average of 2,400 to 2,600 degrees Fahrenheit (1,300 to 1,400 Celsius), and the hot side averages 4,200 degrees Fahrenheit (2,300 Celsius). The difference between the hot and cold sides would need to be more extreme if there were no atmosphere.

    4
    Could super-Earth HD 219134 b be a sapphire planet? (Thibaut Roger/University of Zurich)

    And then there’s another super-earth, HD 219134, that late last year was described as a planet potentially featuring vast collections of different precious stones.

    To back up for a second, researchers study the formation of planets using theoretical models and compare their results with data from observations. It is known that during their formation, stars such as the sun were surrounded by a disc of gas and dust in which planets were born. Rocky planets like the Earth were formed out of the solid bodies left over when the protoplanetary gas disc cooled and dispersed.

    Unlike the Earth however, HD 219134 most likely does not have a massive core of iron — a conclusion flowing from measurements of its density. Instead, through modeling of formation scenarios for a scalding super-Earth close to its host star, the researchers conclude the planet is likely to be rich in calcium and aluminum, along with magnesium and silicon.

    This chemical composition would allow the existence of large quantities of aluminum oxides. On Earth, crystalline aluminum oxide forms the mineral corundum. If the aluminum oxide contains traces of iron, titanium, cobalt or chromium, it will form the noble varieties of corundum, gemstones like the blue sapphire and the red ruby.

    “Perhaps it shimmers red to blue like rubies and sapphires, because these gemstones are aluminum oxides which are common on the exoplanet,” said Caroline Dorn, astrophysicist at the Institute for Computational Science of the University of Zurich.

    5
    A variation on the “eyeball planet” is a water world where the star-facing side is able to maintain a liquid-water ocean, while the rest of the surface is ice. (eburacum45/DeviantArt)

    Super-Earths, which are defined as having a size between that of Earth and Neptune, are also inferred to be the most likely to be water worlds.

    At a Goldschmidt Conference in Boston last year, a study was presented that suggests that some super-Earth exoplanets are likely extremely wet with water – much more so than Earth. Astronomers found more specifically that exoplanets which are between two and four times the size of Earth are likely to have water as a dominant component. Most are thought to be rocky and to have atmospheres, and now it seems that many have ocean, as well.

    The new findings are based on data from the Kepler Space Telescope and the Gaia mission, which show that many of the already known planets of this type (out of more than 4,000 exoplanets confirmed so far) could contain as much as 50 percent water. That upper limit is an enormous amount, compared to 0.02 percent of the water content of Earth.

    This potentially wide distribution of water worlds is perhaps not so surprising given conditions in our solar system, where Earth is wet, Venus and Mars were once wet, Neptune and Uranus are ice giants and moons such as Europa and Enceladus as global oceans beneath their crusts of ice.

    6
    Might this be the strangest planet of all? (NASA)

    As is apparent with the planetary types described so far, whether a planet is typical or atypical is very much up in the air. What is atypical this year may be found to be common in the days ahead.

    The Kepler mission concluded that small, terrestrial planets are likely more common than gas giants, but our technology doesn’t let us identify and characterize many of those smaller, Earth-sized planets.

    Many of the planets discovered so far are quite close to their host stars and thus are scalding hot. Planets orbiting red dwarf stars are an exception, but if you’re looking for habitable planets — and many astronomers are — then red dwarf planets come with other problems in terms of habitability. They are usually tidally locked and they start their days bathed in very high-energy radiation that could stertil1ze the surface for all time.

    A prime goal of the Kepler mission had been to find a planet close enough in character to Earth to be considered a twin. While they have some terrestrial candidates that could be habitable, no twin was found. This may be a function of lacking the necessary technology, or it’s certainly possible (if unlikely) that no Earth twins are out there. Or at least none with quite our collection of conditions favorable to habitability and life.

    With this in mind, my own current candidate for an especially unusual planet is, well, our own. Planet-hunting over the past almost quarter-century leads to that conclusion — for now, at least.

    And it may be that solar systems like ours are highly unusual, too. Pretty surprising, given that not long ago it was considered the norm.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 7:39 am on November 9, 2018 Permalink | Reply
    Tags: Many Worlds, , Probing The Insides of Mars to Learn How Rocky Planets Are Formed, The Tharsis region of Mars has some of the largest volcanoes in the solar system. They include Olympus Mons which is 375 miles in diameter and as much as 16 miles high. (U.S. Geological Survey)   

    From Many Worlds: “Probing The Insides of Mars to Learn How Rocky Planets Are Formed” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    2018-11-08
    Marc Kaufman

    1
    An artist illustration of the InSight lander on Mars. InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, is designed to look for tectonic activity and meteorite impacts, study how much heat is still flowing through the planet, and track Mars’ wobble as it orbits the sun. While InSight is a Mars mission, it will help answer key questions about the formation of the other rocky planets of the solar system and exoplanets beyond. (NASA/JPL-Caltech).

    NASA/Mars InSight Lander

    In the known history of our 4.5-billion-year-old solar system, the insides of but one planet have been explored and studied. While there’s a lot left to know about the crust, the mantle and the core of the Earth, there is a large and vibrant field dedicated to that learning.

    Sometime next month, an extensive survey of the insides of a second solar system planet will begin. That planet is Mars and, assuming safe arrival, the work will start after the InSight lander touches down on November 26.

    This is not a mission that will produce dazzling images and headlines about the search for life on Mars. But in terms of the hard science it is designed to perform, InSight has the potential to tell us an enormous am0unt about the makeup of Mars, how it formed, and possibly why is it but one-third the size of its terrestrial cousins, Earth and Venus.

    “We know a lot about the surface of Mars, we know a lot about its atmosphere and even about its ionosphere,” says Bruce Banerdt, the mission’s principal investigator, in a NASA video. “But we don’t know very much about what goes on a mile below the surface, much less 2,000 miles below the surface.”

    The goal of InSight is to fill that knowledge gap, helping NASA map out the deep structure of Mars. And along the way, learn about the inferred formation and interiors of exoplanets, too.

    2
    Equitorial Mars and the InSight landing site, with noting of other sites. (NASA)

    The lander will touch down at Elysium Planitia, a flat expanse due north of the Curiosity landing site. The destination was selected because it is about as safe as a Mars landing site could be, and InSight did not need to be a more complex site with a compelling surface to explore.

    “While I’m looking forward to those first images from the surface, I am even more eager to see the first data sets revealing what is happening deep below our landing pads.” Barerdt said. “The beauty of this mission is happening below the surface. Elysium Planitia is perfect.”

    By studying the size, thickness, density and overall structure of the Martian core, mantle and crust, as well as the rate at which heat escapes from the planet’s interior, the InSight mission will provide glimpses into the evolutionary processes of all of the rocky planets in the inner solar system.

    That’s because in terms of fundamental processes that shape planetary formation, Mars is an ideal subject.

    It is big enough to have undergone the earliest internal heating and differentiation (separation of the crust, mantle and core) processes that shaped the terrestrial planets (Earth, Venus, Mercury, our moon), but small enough to have retained the signature of those processes over the next four billion years.

    So Mars may contain the most in-depth and accurate record in the solar system of these processes. And because Mars has been less geologically active than the Earth — it does not have plate tectonics, for example — it has retains a more complete evolutionary record in its own basic planetary building blocks. In terms of deep planet geophysics, it is often described as something of a fossil.

    By using geophysical instruments like those used on Earth, InSight will measure the fingerprints of the processes of terrestrial planet formation, as well as measuring the planet’s “vital signs.” They include the “pulse” (seismology), “temperature” (heat flow probe), and “reflexes” (precision tracking).

    One promising way InSight will peer into the Martian interior is by studying motion underground — what we know as marsquakes.

    NASA has not attempted to do this kind of science since the Viking mission. Both Viking landers had their seismometers on top of the spacecraft, where they produced noisy data. InSight’s seismometer will be placed directly on the Martian surface, which will provide much cleaner data.

    As described by the agency, “NASA have seen a lot of evidence suggesting Mars has quakes. But unlike quakes on Earth, which are mostly caused by tectonic plates moving around, marsquakes would be caused by other types of tectonic activity, such as volcanism and cracks forming in the planet’s crust.

    “In addition, meteor impacts can create seismic waves, which InSight will try to detect.

    “Each marsquake would be like a flashbulb that illuminates the structure of the planet’s interior. By studying how seismic waves pass through the different layers of the planet (the crust, mantle and core), scientists can deduce the depths of these layers and what they’re made of. In this way, seismology is like taking an X-ray of the interior of Mars.”

    3
    The InSight seismometer, developed by European partners and JPL, consists of a total of six seismic sensors that record the vibrations of the Martian soil in three directions in space and at two different frequency ranges. ges allows them to be mathematically combined into a single extremely broadband seismometer. In order to protect the seismometer against wind and strong temperature fluctuations, a protective dome (Wind and Thermal Shield, WTS) will be placed over it. (German Aerospace Center [DLR])

    Scientists think it’s likely they’ll see between a dozen and a hundred marsquakes over the course of two Earth years. The quakes are likely to be no bigger than a 6.0 on the Richter scale, which would be plenty of energy for revealing secrets about the planet’s interior.

    Another area of scientific interest involves whether or not the core of Mars is liquid. InSight’s Rotation and Interior Structure Experiment, RISE, will help answer that question by tracking the location of the lander to determine just how much Mars’ North Pole wobbles as it orbits the sun.

    These observations will provide information on the size of Mars’ iron-rich core and will help determine whether the core is liquid. It will also help determine which other elements, besides iron, may be present.

    The InSight science effort includes a self-hammering heat probe that will burrow down to 16 feet into the Martian soil and will for the first time measure the heat flow from the planet’s interior. Combining the rate of heat flow with other InSight data will reveal how energy within the planet drives changes on the surface.

    This is especially important in trying to understand the presence and size of some of the solar system’s largest shield volcanoes in the solar system, a region known as Tharsis Mons.

    3
    The Tharsis region of Mars has some of the largest volcanoes in the solar system. They include Olympus Mons, which is 375 miles in diameter and as much as 16 miles high. (U.S. Geological Survey)

    Heat escaping from deep within the planet drives the formation of these types of features, as well as many others on rocky planets.

    InSight is not an astrobiology mission — no searching for life beyond Earth.

    But it definitely is part of the process by which scientists will learn what planet formation and the dynamics of their interiors says about whether a planet can be home to life.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 12:57 pm on November 1, 2018 Permalink | Reply
    Tags: , , , , , Many Worlds, , ,   

    From Many Worlds: “The Kepler Space Telescope Mission Is Ending But Its Legacy Will Keep Growing” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    From Many Worlds

    2018-11-01
    Marc Kaufman

    NASA/Kepler Telescope

    As of October 2018, the planet-hunting spacecraft has been in space for nearly a decade. (NASA via AP)

    The Kepler Space Telescope is dead. Long live the Kepler.

    NASA officials announced on Tuesday that the pioneering exoplanet survey telescope — which had led to the identification of almost 2,700 exoplanets — had finally reached its end, having essentially run out of fuel. This is after nine years of observing, after a malfunctioning steering system required a complex fix and change of plants, and after the hydrazine fuel levels reached empty.

    While the sheer number of exoplanets discovered is impressive the telescope did substantially more: it proved once and for all that the galaxy is filled with planets orbiting distant stars. Before Kepler this was speculated, but now it is firmly established thanks to the Kepler run.

    It also provided data for thousands of papers exploring the logic and characteristics of exoplanets. And that’s why the Kepler will indeed live long in the world of space science.

    “As NASA’s first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the solar system and beyond,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington.

    “Not only did it show us how many planets could be out there, it sparked an entirely new and robust field of research that has taken the science community by storm. Its discoveries have shed a new light on our place in the universe, and illuminated the tantalizing mysteries and possibilities among the stars.”

    1
    The Kepler Space Telescope was focused on hunting for planets in this patch of the Milky Way. After two of its four spinning reaction wheels failed, it could no longer remain steady enough to stare that those distant stars but was reconfigured to look elsewhere and at a different angle for the K2 mission. (Carter Roberts/NASA)

    Kepler was initially the unlikely brainchild of William Borucki, its founding principal investigator who is now retired from NASA’s Ames Research Center in California’s Silicon Valley.

    3
    William Borucki, originally the main champion for the Kepler idea and later the principal investigator of the mission. His work at NASA went back to the Apollo days. (NASA)

    When he began thinking of designing and proposing a space telescope that could potentially tell us how common distant exoplanets were — and especially smaller terrestrial exoplanets like Earth – the science of extra solar planets was at a very different stage.

    “When we started conceiving this mission 35 years ago we didn’t know of a single planet outside our solar system,” Borucki said. “Now that we know planets are everywhere, Kepler has set us on a new course that’s full of promise for future generations to explore our galaxy.”

    The space telescope was launched in 2009. While Kepler did not find the first exoplanets — that required the work of astronomers using a different technique of observing based on the “wobble” of stars caused by orbiting planets — it did change the exoplanet paradigm substantially.

    Not only did it prove that exoplanets are common, it found that planets outnumber stars in our galaxy (which has hundreds of billions of those stars.)

    In addition it found that small, terrestrial-size planets are common as well, with some 20 to 50 percent of stars likely to have planets of that size and type. And what menagerie of planets it found out there.

    Among the greatest surprises: The Kepler mission provided data showing that the most common sized planets in the galaxy fall somewhere between Earth and Neptune, a type of planet that isn’t present in our solar system.

    It found solar systems of all sizes as well, including some with many planets (as many as eight) orbiting close to their host star.

    The discovery of these compact systems, generally orbiting a red dwarf star, raised questions about how solar systems form: Are these planets “born” close to their parent star, or do they form farther out and migrate in?

    So far, more than 2,500 peer-reviewed papers have been published using Kepler data, with substantial amounts of that data still unmined.

    Natalie Batalha was the project and mission scientist for Kepler for much of its run, and I asked her about its legacy.

    2
    Astrophysicist Natalie Batalha was the Kepler project and mission scientist for a decade. She left NASA recently for the University of California at Santa Cruz “to carry on the Kepler legacy” by creating an interdisciplinary center for the study of planetary habitability.

    “When I think of Kepler’s influence across all of astrophysics, I’m amazed at what such a simple experiment accomplished,” she wrote in an email. “You’d be hard-pressed to come up with a more boring mandate — to unblinkingly measure the brightnesses of the same stars for years on end. No beautiful images. No fancy spectra. No landscapes. Just dots in a scatter plot.

    “And yet time-domain astronomy exploded. We’d never looked at the Universe quite this way before. We saw lava worlds and water worlds and disintegrating planets and heart-beat stars and supernova shock waves and the spinning cores of stars and planets the age of the galaxy itself… all from those dots.”

    4
    The Kepler-62 system is but one of many solar systems detected by the space telescope. The planets within the green discs are in the habitable zones of the stars — where water could be liquid at times. (NASA)

    While Kepler provided remarkable answers to questions about the overall planetary makeup of our galaxy, it did not identify smaller planets that will be directly imaged, the evolving gold standard for characterizing exoplanets. The 150,000 stars that the telescope was observing were very distant, in the range of a few hundred to a few thousand light-years away. One light year is about 6 trillion (6,000,000,000,000) miles.

    Nonetheless, Kepler was able to detect the presence of a handful of Earth-sized planets in the habitable zones of their stars. The Kepler-62 system held one of them, and it is 1200 light-years away. In contrast, the four Earth-sized planets in the habitable zone of the much-studied Trappist-1 system are 39 light-years away.

    Kepler made its observations using the the transit technique, which looks for tiny dips in the amount of light coming from a star caused by the presence of a planet passing in front of the star. While the inference that exoplanets are ubiquitous came from Kepler results, the telescope was actually observing but a small bit of the sky. It has been estimated that it would require around 400 space telescopes like Kepler to cover the whole sky.

    What’s more, only planets whose orbits are seen edge-on from Earth can be detected via the transit method, and that rules out a vast number of exoplanets.

    The bulk of the stars that were selected for close Kepler observation were more or less sun-like, but a sampling of other stars occurred as well. One of the most important factors was brightness. Detecting minuscule changes in brightness caused by transiting planet is impossible if the star is too dim.

    Four years into the mission, after the primary mission objectives had been met, mechanical failures temporarily halted observations. The mission team was able to devise a fix, switching the spacecraft’s field of view roughly every three months. This enabled an extended mission for the spacecraft, dubbed K2, which lasted as long as the first mission and bumped Kepler’s count of surveyed stars up to more than 500,000.

    But it was inevitable that the mission would come to an end sooner rather than later because of that dwindling fuel supply, needed to keep the telescope properly pointed.

    Kepler cannot be refueled because NASA decided to place the telescope in an orbit around the sun that is well beyond the influence of the Earth and moon — to simplify operations and ensure an extremely quiet, stable environment for scientific observations. So Kepler was beyond the reach of any refueling vessel. The Kepler team compensated by flying considerably more fuel than was necessary to meet the mission objectives.

    The video below explains what will happen to the Kepler capsule once it is decommissioned. But a NASA release explains that the final commands “will be to turn off the spacecraft transmitters and disable the onboard fault protection that would turn them back on. While the spacecraft is a long way from Earth and requires enormous antennas to communicate with it, it is good practice to turn off transmitters when they are no longer being used, and not pollute the airwaves with potential interference.”

    And so Kepler will actually continue orbiting for many decades, just as its legacy will continue long after operations cease.

    Kepler’s follow-on exoplanet surveyor — the Transiting Exoplanet Survey Satellite or TESS — was launched this year and has begun sending back data.

    NASA/MIT TESS

    Its primary mission objective is to survey the brightest stars near the Earth for transiting exoplanets. The TESS satellite uses an array of wide-field cameras to survey some 85% of the sky, and is planned to last for two years.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    About Many Worlds

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

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

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

    About NExSS

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

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

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

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

     
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