Tagged: Mars Exploration Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 12:19 pm on June 19, 2017 Permalink | Reply
    Tags: , , , , , Hot rocks not warm atmosphere led to relatively recent water-carved valleys on Mars, Lyot impact crater, Mars Exploration   

    From Brown: “Hot rocks, not warm atmosphere, led to relatively recent water-carved valleys on Mars” 

    Brown University
    Brown University

    June 13, 2017
    Kevin Stacey
    kevin_stacey@brown.edu
    401-863-3766

    1
    Valley Networks.Lyot Crater, rendered here with elevations exaggerated, is home to relatively recent water-carved valleys (white streaks). New research suggests the water came from melting snow and ice present at the time of the crater-forming impact.
    David Weiss/NASA/Brown University

    New research shows that water from melted snow and ice likely carved valley networks around Lyot crater on Mars.

    Present-day Mars is a frozen desert, colder and more arid than Antarctica, and scientists are fairly sure it’s been that way for at least the last 3 billion years. That makes a vast network of water-carved valleys on the flanks of an impact crater called Lyot — which formed somewhere between 1.5 billion and 3 billion years ago — something of a Martian mystery. It’s not clear where the water came from.

    Now, a team of researchers from Brown University has offered what they see as the most plausible explanation for how the Lyot valley networks formed. They conclude that at the time of the Lyot impact, the region was likely covered by a thick layer of ice. The giant impact that formed the 225-kilometer crater blasted tons of blazing hot rock onto that ice layer, melting enough of it to carve the shallow valleys.

    “Based on the likely location of ice deposits during this period of Mars’ history, and the amount of meltwater that could have been produced by Lyot ejecta landing on an ice sheet, we think this is the most plausible scenario for the formation of these valleys” said David Weiss, a recent Ph.D. graduate from Brown and the study’s lead author.

    Weiss co-authored the study, which is published in Geophysical Research Letters, with advisor and Brown planetary science professor Jim Head, along with fellow graduate students Ashley Palumbo and James Cassanelli.

    There’s plenty of evidence that water once flowed on the Martian surface. Water-carved valley networks similar to those at Lyot have been found in several locations. There’s also evidence for ancient lake systems, like those at Gale Crater where NASA’s Curiosity rover is currently exploring and at Jezero Crater where the next rover may land.

    Most of these water-related surface features, however, date back to very early in Mars’ history — the epochs known as the Noachian and the Hesperian, which ended about 4 billion and 3 billion years ago respectively. From about 3 billion years ago to the present, Mars has been in a bone-dry period called the Amazonian.

    The valley networks at Lyot therefore are a rare example of more recent surface water activity. Scientists have dated the crater itself to the Amazonian, and the valley networks appear to have been formed around the same time or shortly after the impact. So the question is: Where did all that water come from during the arid Amazonian?

    Scientists have posited a number of potential explanations, and the Brown researchers set out to investigate several of the major ones.

    One of those potential explanations, for example, is that there might have been a vast reservoir of groundwater when the Lyot impact occurred. That water, liberated by impact, could have flowed onto the surface along the periphery of the crater and carved the valleys. But based on geological evidence, the researchers say, that scenario is unlikely

    “If these were formed by deep groundwater discharge, that water would have also flowed into the crater itself,” Weiss said. “We don’t see any evidence that there was water present inside the crater.”

    The researchers also looked at the possibility of transient atmospheric effects following the Lyot impact. A collision of this size would have vaporized tons of rock, sending a plume of vapor into the air. As that hot plume interacted with the cold atmosphere, it could have produced rainfall that some scientists think might have carved the valleys.

    But that, too, appears unlikely, the researchers concluded. Any rain related to the plume would have fallen after the rocky impact ejecta had been deposited outside the crater. So if rainwater carved the valleys, one would expect to see valleys cutting through the ejecta layer. But there are almost no valleys directly on the Lyot ejecta. Rather, Palumbo said, “The vast majority of the valleys seem to emerge from beneath the ejecta on its outer periphery, which casts serious doubt on the rainwater scenario.”

    That left the researchers with the idea that meltwater, produced when hot ejecta interacted with an icy surface, carved the Lyot valleys.

    According to models of Mars’ climate history, ice now trapped mainly at the planet’s poles often migrated into the mid-latitude regions where Lyot is located. And there’s evidence to suggest that an ice sheet was indeed present in the region at the time of the impact.

    Some of that evidence comes from the scarcity of secondary craters at Lyot. Secondary craters form when big chunks of rock blasted into the air during a large impact fall back to the surface, leaving a smattering of small craters surrounding the main crater. At Lyot, there far fewer secondary craters than one would expect, the researchers say. The reason for that, they suggest, is that instead of landing directly on the surface, ejecta from Lyot landed on a thick layer of ice, which prevented it from gouging the surface beneath the ice. Based on the terrain on the northern side of Lyot, the team estimates that the ice layer could have been anywhere from 20 to 300 meters thick.

    The Lyot impact would have spat tons of rock onto that ice layer, some of which would have been heated to 250 degrees Fahrenheit or more. Using a thermal model of that process, the researchers estimate that the interaction between those hot rocks and a surface ice sheet would have produced thousands of cubic kilometers of meltwater — easily enough to carve the valley seen at Lyot.

    “What this shows is a way to get large amounts of liquid water on Mars without the need for a warming of the atmosphere and any liquid groundwater,” Cassanelli said. “So we think this is a good explanation for how you get these channels forming in the Amazonian.”

    And it’s possible, Head says, that this same mechanism could have been important before the Amazonian. Some scientists think that even in the early Noachian and Hesperian epochs, Mars was still quite cold and icy. If that was the case, then this meltwater mechanism might have also been responsible for at least some of the more ancient valley networks on Mars.

    “It’s certainly a possibility worth investigating,” Head said.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    Welcome to Brown

    Brown U Robinson Hall
    Located in historic Providence, Rhode Island and founded in 1764, Brown University is the seventh-oldest college in the United States. Brown is an independent, coeducational Ivy League institution comprising undergraduate and graduate programs, plus the Alpert Medical School, School of Public Health, School of Engineering, and the School of Professional Studies.

    With its talented and motivated student body and accomplished faculty, Brown is a leading research university that maintains a particular commitment to exceptional undergraduate instruction.

    Brown’s vibrant, diverse community consists of 6,000 undergraduates, 2,000 graduate students, 400 medical school students, more than 5,000 summer, visiting and online students, and nearly 700 faculty members. Brown students come from all 50 states and more than 100 countries.

    Undergraduates pursue bachelor’s degrees in more than 70 concentrations, ranging from Egyptology to cognitive neuroscience. Anything’s possible at Brown—the university’s commitment to undergraduate freedom means students must take responsibility as architects of their courses of study.

     
  • richardmitnick 10:43 am on June 13, 2017 Permalink | Reply
    Tags: , , , , Mars Exploration, Mars Rover Concept Vehicle (MRCV),   

    From Universe Today: “We’d Like One of These For Here on Earth. NASA’s New Mobile Mars Laboratory Concept Rover” 

    universe-today

    Universe Today

    13 June , 2017
    Matt Williams

    1
    The Mars Rover Concept Vehicle, unveiled on June 5th to kick off NASA’s Summer of Mars. Credit: NASA/Kim Shiflett

    When it comes time to explore Mars with crewed missions, a number of challenges will present themselves. Aside from the dangers that come with long-duration missions to distant bodies, there’s also the issue of the hazards presented by the Martian landscape. It’s desiccated ans cold, it gets exposed to a lot of radiation, and its pretty rugged to boot! So astronauts will need a way to get around and conduct research in comfort and safety.

    To meet this challenge, NASA created a vehicle that looks like it could give the Batmobile a run for its money! It’s known as the Mars Rover Concept Vehicle (MRCV) a working vehicle/mobile laboratory that was unveiled last week (June 5th, 2017) to kick off NASA’s Summer of Mars. Those who attended the event at the Kennedy Space Center Visitor Complex were fortunate to be the first to see the new Mars explorer vehicle up close.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 8:46 pm on June 7, 2017 Permalink | Reply
    Tags: , CRISM (Compact Reconnaissance Imaging Spectrometer for Mars), , Janice Bishop, Janice Bishop Explores Mawrth Vallis and Salt Ponds in Australia, Mars Exploration, Mawrth Vallis, ,   

    From SETI Institute: “Janice Bishop Explores Mawrth Vallis and Salt Ponds in Australia” 

    SETI Logo new
    SETI Institute

    June 06, 2017
    Janice Bishop

    Mawrth Vallis (Mawrth means Mars in Welsh) is a valley on the planet Mars, with a deep channel formed by water in Mars’ ancient past. In 2016, SETI Institute chemist and planetary scientist Janice Bishop made an interesting discovery about the composition of rock layers that form the valley using data collected by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).

    CRISM is an instrument on the Mars Reconnaissance Orbiter (MRO) which was launched in 2005 and remains in orbit around Mars searching for evidence of past water.

    1
    CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) searches for the residue of minerals that form in the presence of water, perhaps in association with ancient hot springs, thermal vents, lakes, or ponds that may have existed on the surface of Mars.

    Even though some landforms provide evidence that liquid water may have flowed on the surface of Mars long ago, evidence of mineral deposits created by long-term interaction between water and rock has been limited.

    CRISM’s visible and infrared spectrometers track regions on the dusty martian surface and map them at scales as small as 18 meters (60 feet) across, from an altitude of 300 kilometers (186 miles). CRISM reads the hundreds of “colors” in reflected sunlight to detect patterns that indicate certain minerals on the surface, including signature traces of past water.
    The principal investigator (lead scientist) for CRISM is Scott Murchie from the Applied Physics Lab at Johns Hopkins University.

    From an altitude of 186 miles above the surface of Mars, CRISM collects visible and infrared signatures of certain minerals, including those that hold traces of past water. Using this orbital spectral data from CRISM, Janice identified a unique material sandwiched between two clay-bearing strata. This new phase appears to be mixtures of sulfates and acid-altered clays. One of the puzzling parts of this investigation is that two kinds of sulfates have been identified here: an acidic Fe-sulfate called jarosite and a neutral Ca-sulfate called gypsum. These two sulfates are not normally found together because of their different pH requirements.

    CRISM is an instrument on the Mars Reconnaissance Orbiter (MRO) which was launched in 2005 and remains in orbit around Mars searching for evidence of past water. From an altitude of 186 miles above the surface of Mars, CRISM collects visible and infrared signatures of certain minerals, including those that hold traces of past water. Using this orbital spectral data from CRISM, Janice identified a unique material sandwiched between two clay-bearing strata. This new phase appears to be mixtures of sulfates and acid-altered clays. One of the puzzling parts of this investigation is that two kinds of sulfates have been identified here: an acidic Fe-sulfate called jarosite and a neutral Ca-sulfate called gypsum. These two sulfates are not normally found together because of their different pH requirements.

    2
    Mars Reconnaissance Orbiter credit: NASA

    Here on Earth, other scientists have found combinations of jarosite, gypsum, as well as halite and clays in the highly saline ponds found in the desert of Western Australia. Apparently, the high salt (S, Cl) level enables formation of these sulfates in this kind of environment. Janice and SETI Institute colleague Lukas Gruendler recently visited these salt ponds in the Archean Yilgarn Craton region of Western Australia looking for mixtures of clays and sulfates similar to those Janice discovered in some of the clay-rich regions of Mars.

    3
    Janice and Lukas hold up the expedition flag.

    Janice and Lukas decided to study samples from three of these sites in order to characterize the mineralogy of the surface crust and the material down a few centimeters in the hopes of learning about environments that could help us understand this puzzling salty outcrop on Mars.

    Sample analysis will continue in Janice’s mineral lab here at the SETI Institute and will help learn more about both Earth and Mars.

    3
    Janice collecting samples at a salt pond
    4

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    SETI Institute – 189 Bernardo Ave., Suite 100
    Mountain View, CA 94043
    Phone 650.961.6633 – Fax 650-961-7099
    Privacy PolicyQuestions and Comments

     
  • richardmitnick 2:13 pm on May 15, 2017 Permalink | Reply
    Tags: , , , , Mars Exploration,   

    From JPL-Caltech: “Mars Rover Opportunity Begins Study of Valley’s Origin” 

    NASA JPL Banner

    JPL-Caltech

    May 15, 2017
    Guy Webster
    Jet Propulsion Laboratory, Pasadena, Calif.
    guy.webster@jpl.nasa.gov
    818-354-6278

    Andrew Good
    Jet Propulsion Laboratory, Pasadena, Calif.
    andrew.c.good@jpl.nasa.gov
    818-393-2433

    Laurie Cantillo
    NASA Headquarters, Washington
    laura.l.cantillo@nasa.gov
    202-358-1077

    Dwayne Brown
    NASA Headquarters, Washington
    dwayne.c.brown@nasa.gov
    202-358-1726

    1
    Putting Martian ‘Tribulation’ Behind

    NASA’s Mars Exploration Rover Opportunity worked for 30 months on a raised segment of Endeavour Crater’s rim called “Cape Tribulation” until departing that segment in mid-April 2017, southbound toward a new destination. This view looks back at the southern end of Cape Tribulation from about two football fields’ distance away.

    NASA/Mars Opportunity Rover

    The component images were taken by the rover’s Panoramic Camera (Pancam) on April 21, during the 4,707th Martian day, or sol, of Opportunity’s mission on Mars.

    Wheel tracks can be traced back to see the rover’s route as it descended and departed Cape Tribulation. For scale, the distance between the two parallel tracks is about 3.3 feet (1 meter). The rover drove from the foot of Cape Tribulation to the head of “Perseverance Valley” in seven drives totaling about one-fifth of a mile (one-third of a kilometer). An annotated map of the area is at PIA21496.

    The elevation difference between the highest point visible in this scene and the rover’s location when the images were taken is about 180 feet (55 meters).

    This view looks northward. It merges exposures taken through three of the Pancam’s color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). It is presented in approximately true color.

    2
    This graphic shows the route that NASA’s Mars Exploration Rover Opportunity drove in its final approach to ‘Perseverance Valley’ on the western rim of Endeavour Crater.

    The map covers an area about four-tenths of a mile (two-thirds of a kilometer) wide, with the interior of the crater on the right. Opportunity entered this mapped area from the north along the gold traverse line on March 21, 2017, approaching the southern tip of the “Cape Tribulation” segment of Endeavour’s rim. It reached the top of “Perseverance Valley” with a drive on Sol 4720 (the 4,720th Martian day) of the mission, on May 4, 2017.

    Images showing more of the Endeavour Crater rim are at PIA21490 and PIA17758.

    The base image for this map is from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. The annotated map was produced at the New Mexico Museum of Natural History and Science, Albuquerque.

    NASA’s Mars Exploration Rover Opportunity has reached the main destination of its current two-year extended mission — an ancient fluid-carved valley incised on the inner slope of a vast crater’s rim.

    As the rover approached the upper end of “Perseverance Valley” in early May, images from its cameras began showing parts of the area in greater resolution than what can be seen in images taken from orbit above Mars.

    “The science team is really jazzed at starting to see this area up close and looking for clues to help us distinguish among multiple hypotheses about how the valley formed,” said Opportunity Project Scientist Matt Golombek of NASA’s Jet Propulsion Laboratory, Pasadena, California.

    The process that carved Perseverance Valley into the rim of Endeavour Crater billions of years ago has not yet been identified. Among the possibilities: It might have been flowing water, or might have been a debris flow in which a small amount of water lubricated a turbulent mix of mud and boulders, or might have been an even drier process, such as wind erosion. The mission’s main objective with Opportunity at this site is to assess which possibility is best supported by the evidence still in place.

    The upper end of the valley is at a broad notch in the crest of the crater rim. The rover team’s plan for investigating the area begins with taking sets of images of the valley from two widely separated points at that dip in the rim. This long-baseline stereo imaging will provide information for extraordinarily detailed three-dimensional analysis of the terrain. The valley extends down from the rim’s crest line into the crater, at a slope of about 15 to 17 degrees for a distance of about two football fields.

    “The long-baseline stereo imaging will be used to generate a digital elevation map that will help the team carefully evaluate possible driving routes down the valley before starting the descent,” said Opportunity Project Manager John Callas of JPL.

    Reversing course back uphill when partway down could be difficult, so finding a path with minimum obstacles will be important for driving Opportunity through the whole valley. Researchers intend to use the rover to examine textures and compositions at the top, throughout the length and at the bottom, as part of investigating the valley’s history.

    While the stereo imaging is being analyzed for drive-planning, the team plans to use the rover to examine the area immediately west of the crater rim at the top of the valley. “We expect to do a little walkabout just outside the crater before driving down Perseverance Valley,” Golombek said.

    The mission has begun its 150th month since the early 2004 landing of Opportunity in the Meridiani Planum region of Mars. In the first three months, which were originally planned as the full length of the mission, it found evidence in rocks that acidic water flowed across parts of Mars and soaked the subsurface early in the planet’s history.

    For nearly half of the mission — 69 months — Opportunity has been exploring sites on and near the western rim of Endeavour Crater, where even older rocks are exposed. The crater spans about 14 miles (22 kilometers) in diameter. Opportunity arrived from the northwest at a point corresponding to about the 10 o’clock position on the circle if north is noon; Perseverance Valley slices west to east at approximately the 8 o’clock position.

    Opportunity hustled southward to reach the crown of the valley in recent weeks. In mid-April it finished about two-and-a-half years on a rim segment called “Cape Tribulation.” In seven drives between then and arriving at the destination on May 4, it covered 377 yards (345 meters), bringing the mission’s total odometry to about 27.8 miles (44.7 kilometers).

    Opportunity and the next-generation Mars rover, Curiosity, as well as three active NASA Mars orbiters and surface missions to launch in 2018 and 2020 are all part of ambitious robotic exploration to understand Mars, which helps lead the way for sending humans to Mars in the 2030s.

    NASA/Mars Curiosity Rover

    JPL, a division of Caltech in Pasadena, California, built Opportunity and manages the mission for NASA’s Science Mission Directorate, Washington. For more information about Opportunity, visit:

    http://www.nasa.gov/rovers

    http://marsrovers.jpl.nasa.gov

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    Caltech Logo

    NASA image

     
  • richardmitnick 8:46 am on May 1, 2017 Permalink | Reply
    Tags: , , , , Mars Exploration, Martian landscape created by two distinct asteroid epochs   

    From COSMOS: “Martian landscape created by two distinct asteroid epochs” 

    Cosmos Magazine bloc

    COSMOS

    01 May 2017
    Tim Wallace

    1
    Major impacts on the Martian surface include the ancient giant Borealis basin (top of globe), Hellas (bottom right), and Argyre (bottom left).There appears to have been a 400-million-year lull in impacts between the formation of Borealis and the younger basins. University of Arizona/LPL/Southwest Research Institute

    It’s magnitude, and infrequency that counts in explaining how asteroid impacts shaped Mars, with new research dramatically revising down the number of giant asteroids that crashed into the Red Planet to just one-tenth of some previous estimates.

    The analysis by planetary scientists Wiilliam Bottke, of the Southwest Research Institute, in Colorado, and Jeff Andrews-Hanna, of the University of Arizona’s Lunar and Planetary Laboration, suggests a lull of 400 million years between two periods of intense asteroid numbers and collisions. The first led to the most significant asteroid impact on Mars 4.5 million years ago, while the second to four more giant impacts between 4.1 and 3.8 million years ago.

    In their paper published in Nature Geoscience, Bottke and Andrews-Hanna argue on the basis of topographical, gravitational and geochemical analyses against there being any gradual decline in impact events.

    Rather, the surface of Mars bears the signature of two distinct periods of intense asteroid activity within the inner Solar System; the earlier period of asteroid impacts associated with the formation of the inner planets; and the later period with the Late Heavy Bombardment, the cause of which a number of explanations have been proposed including the migration of the giant planets.

    The most striking aspect of the topography of Mars is the contrast between the remarkably flat lowlands of it northern hemisphere known as the Borealis basin, covering about 40% of the planet’s surface, and the hilly highlands of the southern hemisphere. The calculations by Bottke and Andrews-Hanna concur with previous estimates the northern polar basin – was formed by the impact of an asteroid between 1,100 and 2,300 kilometres wide.

    Only one subsequent major asteroid impact, creating the basin known as the Isidis Planitia, has impinged upon the Borealis crater, the researchers argue.

    “This sets strong statistical limits on the number of giant basins that could have formed on Mars after Borealis”, says Bottke, who is also a principal investigator with NASA’s Solar System Exploration Research Virtual Institute (SSERVI). “The number and timing of such giant impacts on early Mars has been debated, with estimates ranging from four to 30 giant basins formed in the time since Borealis. Our work shows that the lower values are more likely.”

    The similar preservation states of the between most visible impact structures on Mars – the Borealis basin and the Hellas, Isidis and Argyre craters formed more than 400,000 years later, also points to the lull which Bottke and Andrew-Hanna call “the doldrums”, as any impact basins formed in the interim should have been similarly preserved.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 11:38 am on December 14, 2016 Permalink | Reply
    Tags: Boron, , Mars Exploration   

    From Many Worlds: “With The Discovery of Boron on Mars, The Package of Chemicals Needed For Life May Well Be Complete” 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2016-12-14
    Marc Kaufman

    1
    Using its laser technology, the Curiosity ChemCam instrument located the highest abundance of boron observed so far on this raised calcium sulfate vein. The red outline shows the location of the ChemCam target remote micro images (inset). The remote micro images show the location of each individual ChemCam laser point (red crosshairs) and the additional chemistry associated with each point (colored bars). JPL-Caltech/MSSS/LANL/CNES-IRAP/William Rapin

    NASA/Mars Curiosity Rover
    NASA/Mars Curiosity Rover

    For years, noted chemist and synthetic life researcher Steven Benner has talked about the necessary role of the element boron in the origin of life.

    Without boron, he has found, the process needed to form the earliest self-replicating ribonucleic acid (RNA) falls apart when it comes into contact with water, which it also necessary for the process to succeed. Only in the presence of boron, Benner found and has long argued, can the formation of RNA and later DNA proceed.

    Now, to the delight of Benner and many other scientists, the Curiosity team has found boron on Mars. In fact, as Curiosity climbs the mountain at the center of Gale Crater, the presence of boron has become increasingly pronounced.

    3
    A shaded and colorized topographic map of Gale Crater, Mars, based on publicly released High Resolution Stereo Camera (HRSC) data. The MSL landing ellipse is indicated in the northwestern crater floor.
    14 September 2010
    Source Anderson and Bell, 2010
    Author Ryan Anderson

    And to make the discovery all the more meaningful to Benner, the boron is being found in rock veins. So it clearly was carried by water into the fractures, and was deposited there some 3.5 billion years ago.

    Combined with earlier detections of phosphates, magnesium, peridots, carbon and other essential elements in Gale Crater, Benner told me, “we have found on Mars an environment entirely consistent with a what we consider conducive for the origin of life.

    “Is it likely that life arose? I’d say yes…perhaps even, hell yes. But it’s also true that an environment conducive to the formation of life isn’t necessarily one conducive to the long-term survival of life.”

    5
    The foreground of this scene from the Mastcam on NASA’s Curiosity Mars rover shows purplish rocks near the rover’s late-2016 location. The middle distance includes future destinations for the rover. Variations in color of the rocks hint at the diversity of their composition on lower Mount Sharp. NASA/JPL-Caltech/MSSS

    Another factor in the Mars-as-habitable story from Benner’s view is that there has never been the kind of water world there that many believe existed on early Earth.

    While satellites orbiting Mars and now Curiosity have made it abundantly clear that early Mars also had substantial water in the form of lakes, rivers, streams and perhaps an localized ocean, it was clearly never covered in water.

    And that’s good for the origin of life, Benner said.

    “We think that a largely arid environment, with water present but not everywhere, is the best one for life to begin. Mars had that but Earth, well, maybe not so much. The problem is how to concentrate the makings of RNA, of life, in a vast ocean. It’s like making a cake in water — all the ingredients will float away.

    “But the mineral ensemble they’ve discovered and given us is everything we could have asked for, and it was on a largely dry Mars,” he said. “So they’ve kicked the ball back to us. Now we have to go back to our labs to enrich the chemistry around this ensemble of minerals.”

    In his labs, Benner has already put together a process — he calls it his discontinuous synthesis model — whereby all the many steps needed to create RNA and therefore life have been demonstrated to be entirely possible.

    What’s missing is a continuous model that would show that process at work, starting with a particular atmosphere and particular minerals and ending up with RNA. That’s something that requires a lot more space and time that any lab experiments would provide.

    “This is potentially what Mars provides,” he said,

    Benner, it should be said, is not a member of the Curiosity team and doesn’t speak for them.

    But his championing of boron as a potentially key element for the origin of life was noted as a guide by one of the Curiosity researchers during a press conference with team members at the American Geophysical Union Dec. 13 in San Francisco. It was at that gathering that the detection of the first boron on Mars was announced.

    Benner said he has been in close touch with the two Curiosity instrument teams involved in the boron research and was most pleased that his own boron work — and that of at least one other researcher — had helped inspire the search for and detection of the element on Mars. That other researcher, evolutionary biologist James Stephenson, had detected boron in a meteorite from Mars.

    Patrick Gasda, a postdoctoral researcher at Los Alamos National Laboratory, is a member of the Chemistry and Camera (ChemCam) instrument team which identified the boron at Gale Crater. The instrument uses laser technology to identify chemical elements in Martian rocks.

    Gasda said at AGU that if the boron they found in calcium sulfate rock veins on Mars behaves there as it does on Earth, then the environment was conducive to life. The ancient groundwater that formed these veins would have had temperatures in the 0-60 degrees Celsius (32-140 degrees Fahrenheit) range, he said, with a neutral-to-alkaline pH.

    While the presence of boron (most likely the mineral form borate, Benner said) has increased as the rover has climbed Mount Sharp, the element still makes up only one-tenth of one percent of the rock composition. But to stabilize that process of making RNA, that’s enough.

    6
    A drawing of Gale Crater as it is organized now. Water moving beneath the ground, as well as water above the surface in ancient rivers and lakes, provided favorable conditions for microbial life, if Mars has ever hosted life. A well-done animation including a second drawing showing conditions 3.5 billion years ago at Gale can be seen here. It toggles back and forth to show how things have changed. (NASA/JPL-Caltech)

    Benner’s view of Gale Crater and Mars as entirely habitable is not new — the Curiosity team has been saying roughly the same for several years now. But with four full years on Mars the rover keeps adding to the habitability story, and that was the central message from Curiosity scientists speaking at the AGU press conference.

    As the rover examines higher, younger layers, the researchers said they were especially impressed by the complexity of the ancient lake environments at Gale when sediments were being deposited, and also the complexity of the groundwater interactions after the sediments were buried.

    “There is so much variability in the composition at different elevations, we’ve hit a jackpot,” said John Grotzinger of Caltech, and formerly the mission scientist for Curiosity.

    “A sedimentary basin such as this is a chemical reactor. Elements get rearranged. New minerals form and old ones dissolve. Electrons get redistributed. On Earth, these reactions support life.”

    This kind of reactivity occurs on a gradient based on the strength of a chemical at donating or receiving electrons. Transfer of electrons due to this gradient can provide energy for life.

    6
    An illustration of the ChemCam instrument, with its laser zapper, which identified the element boron as Curiosity climbs Mount Sharp. (NASA)

    While habitability is key to Curiosity’s mission on Mars, much additional science is being done that has different goals or looks more indirectly at the planet’s ancient (or possibly current) ability to support life. Understanding the ancient environmental history of Gale Crater and Mars is a good example.

    For instance, the Curiosity team is now undertaking a drilling campaign in progressively younger rock layers, digging into four sites each spaced about 80 feet (about 25 meters) further uphill. Changes in which minerals are present and in what percentages they exist give insights into some of that ancient history.

    One clue to changing ancient conditions is the presence of the mineral hematite, a form of the omnipresent iron oxide on Mars. Hematite has replaced magnetite as the dominant iron oxide in rocks Curiosity has drilled recently, compared with the site where Curiosity first found lake bed sediments.

    Thomas Bristow of NASA Ames Research Center, who works with the Chemistry and Mineralogy (CheMin) laboratory instrument inside the rover, said Mars is sending a signal. Both forms of iron oxide (hematite and magnetite) were deposited in mudstone in what was once the bottom of a lake, but the increased abundance of hematite higher up Mount Sharp suggests conditions were warmer when it was laid down. There also was probably more interaction between the atmosphere and the sediments.

    On a more technical level, an increase in hematite relative to magnetite also indicates an environmental change towards a stronger tug on the iron oxide electrons, causing a greater degree of oxidation (the loss of electrons) in the iron. That would likely be caused by changing atmospheric conditions.

    It’s all part of putting together the jigsaw puzzle of Mars circa 3.5 billion years ago.

    7
    This view from the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover shows an outcrop with finely layered rocks within the “Murray Buttes” region on lower Mount Sharp. (NASA/JPL-Caltech/MSSS)

    Returning to the boron, Benner said that the discovered presence of all the chemicals his group believes are necessary to ever-so-slowly move from prebiotic chemistry to biology provides an enormous opportunity. Because of plate tectonics on Earth and the omnipresence of biology, the conditions and environments present on early Earth when life first arose were long ago destroyed.

    But on Mars, the apparent absence of those most powerful agents of change means it’s possible to detect, observe and study conditions in a changed but intact world that just might have given rise to life on Mars. Taken a step further, Mars today could provide new and important insights into how life arose on Earth.

    And then there’s the logic of what finding signs of ancient, or perhaps deep-down surviving life on Mars would mean to the larger search for life in the cosmos.

    That life exists on one planet among the hundreds of billions we now know are out there suggests that other planets — which we know have many or most of the same basic chemicals as Earth — might have given rise to life as well.

    And if two planets in one of those many, many solar system have produced and supported life, then the odds go up dramatically regarding life on other planets.

    One planet with life could be an anomaly. Two nearby planets with life, even if its similar, are a trend.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 2:41 pm on December 9, 2016 Permalink | Reply
    Tags: , , , Could these Earth fossils give clues to life in outer space?, Mars Exploration   

    From Astronomy: “Could these Earth fossils give clues to life in outer space?” 

    Astronomy magazine

    astronomy.com

    December 08, 2016
    Stephanie Margaret Bucklin

    1
    One of the largest concentrations of Riftia pachyptila observed, with anemones and mussels colonizing in close proximity.
    WikiMedia Commons

    It’s no secret that life on other planets may look very different than life on Earth. But could extremophiles—those organisms that live in the most extreme environments on earth, including hydrothermal vents and inside Earth’s crust—provide some clues about the life that we might expect to find in space?

    The answer may be yes: such organisms, some scientists say, may help us understand the rich variety of life that we could expect to find elsewhere in space.

    “Research that expands our knowledge of the environmental limits of life is indispensable as a strategic element of astrobiological exploration,” said Jack Farmer, Professor of Geobiology at Arizona State University and a participating scientist on the Mars Exploration Rover mission.

    One such research study published in Geology provides some intriguing clues as to just what this bacteria could look like. A team of scientists from the University of Cincinnati discovered fossils in two separate locations that appear to be somewhere between 2.5 and 3.5 billion years old, from the Archean Eon. The fossils, found in the Northern Cape Province of South Africa, are the oldest sulfur-oxidizing bacteria (bacteria that are able to derive energy by oxidizing hydrogen sulfide into sulfur) that have thus been found, and likely lived in a deep-water environment containing little to no oxygen.

    The bacteria likely lived at a time when the atmosphere on Earth had oxygen levels of less than 1 percent—and less than one-thousandth of one percent of what they are today, according to a press release on the study. While the bacteria are much larger than most modern bacteria, they are similar to some single-celled organisms that live in sulfur-rich parts of the deep ocean today.

    “These are some of the largest fossil cells ever found in the Archean Eon,” Andrew Czaja, assistant professor at the University of Cincinnati in the Department of Geology and the first author of the paper, told Astronomy. “Only a couple of other examples of deep marine fossil microorganisms have been reported from any time in the geologic record.”

    The study, Czaja added, could help expand the types of environments in which we can find evidence of past life. Czaja said research into extremophiles in general gives scientists confidence that life can exist anywhere where the appropriate building blocks, including a liquid medium (such as water) and a source of energy, exist.

    “Every time we find evidence of life in a new type of environment on Earth, we increase our confidence in finding life on another planet,” Czaja told Astronomy.

    Another use of extremophile research? Helping scientists figure out where, exactly, to search for life on other planets: Czaja noted that studies like his own could help scientists select a landing site for future space missions.

    Farmer agrees: when seeking life on other planets, he told Astronomy, we tend to “follow habitability,” meaning that we seek zones where the basic requirements for life are met, which is informed by our prior knowledge of what the environmental limits of life are.

    “When paleontologists go to South Africa and explore for an Archean fossil record, they are essentially going to another planet—the early Earth,” Farmer said. What we learn there then informs our strategies on how we look for life on other planets, especially fossil records on other planets.

    One such mission? NASA’s next Mars rover, which NASA will send to space in 2020 in order to search for the biosignatures of life, Farmer said. According to a press release on the mission, the rover will investigate a specific region of Mars that may, at one point in the ancient past, have had favorable conditions for microbial life.

    Still, not all scientists are confident that such extremophiles may provide clues about life on other planets. Malcolm Walter, professor of astrobiology at the University of New South Wales in Sydney and the director of the Australian Center for Astrobiology, told Astronomy that information about extremophiles on Earth does not change his own views about the life we might expect to find on other planets.

    “It gets very speculative,” Walter said. “We know so little about environments of planets beyond our solar system.” Since, Walter continued, we only have one sample of life—life on Earth—it’s difficult to predict what types of organisms we might encounter in space.

    Interestingly, though, Walter noted that in our own solar system, some rocks can get blasted off from one planet and land on another, potentially even carrying microbial life with them.

    Thus, it’s possible that the life we find in space may be very similar to our own, if it shares a single source. Additional research and exploration may shed more light on these possibilities.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
  • richardmitnick 4:18 am on December 9, 2016 Permalink | Reply
    Tags: , , , Mars Exploration,   

    From Many Worlds: Women in STEM – “The Search for Organic Compounds On Mars Is Getting Results” Jennifer Eigenbrode 

    NASA NExSS bloc

    NASA NExSS

    Many Words icon

    Many Worlds

    2016-12-08
    Marc Kaufman

    1
    Sedimentary rocks of the Kimberley Formation in Gale Crater, as photographed in 2015. The crater contains thick deposits of finely-laminated mudstone from fine-grained sediments deposited in a standing body of water that persisted for a long period of time. Scientists have now reported several detections of organic compounds — the building blocks of life in Gale Crater samples. (NASA/JPL-Caltech/MSSS)

    One of the primary goals of the Curiosity mission to Mars has been to search for and hopefully identify organic compounds — the carbon-based molecules that on Earth are the building blocks of life.

    NASA/Mars Curiosity Rover
    NASA/Mars Curiosity Rover

    No previous mission had quite the instruments and capacity needed to detect the precious organics, nor did they have the knowledge about Martian chemistry that the Curiosity team had at launch.

    Nonetheless, finding organics with Curiosity was no sure things. Not only is the Martian surface bombarded with ultraviolet radiation that breaks molecules apart and destroys organics, but also a particular compound now known to be common in the soil will interfere with the essential oven-heating process used by NASA to detect organics.

    So when Jennifer Eigenbrode, a biochemist and geologist at the Goddard Space Flight Center and a member of the Curiosity organics-searching team, asked her colleagues gathered for Curiosity’s 2012 touch-down whether they thought organics would be found, the answer was not pretty.

    “I did a quick survey across the the team and I was convinced that a majority in the room were very doubtful that we would ever detect organics on Mars, and certainly not in the top five centimeters or the surface.”

    Yet at a recent National Academies of Sciences workshop on “Searching for Life Across Space and Time,” Eigenbrode gave this quite striking update:

    “At this point, I can clearly say that I am convinced, and I hope you will be too, that organics are all over Mars, all over the surface, and probably through the rock record. What does that mean? We’ll have to talk about.”

    2
    The hole drilled into this rock target, called “Cumberland,” was made by NASA’s Mars rover Curiosity on May 19, 2013. (NASA/JPL-Caltech/MSSS)

    This is not, it should be said, the first time that a member of the Curiosity “Sample Analysis on Mars” (SAM) team has reported the discovery of organic material. The simple, but very important organic gas methane was detected in Gale Crater, as were chlorinated hydrocarbons and some nonchlorinated organics. Papers by Sushil Atreya, Daniel Glavin and Carol Freissinet, along with other team members from the Goddard SAM team, have been published on all these finds.

    But Eigenbrode’s findings and comments — which acknowledged the essential work of SAM colleagues — move the organics story substantially further.

    That’s because her detections involve larger organic compounds, or rather pieces of what were once larger organics. What’s more, these organics were found only when the Mars samples were cooked at over over 800 degrees centigrade in the SAM oven, while the earlier ones came off as detectable gases at significantly lower temperatures.

    3
    Goddard biogeochemist Jennifer Eigenbrode, an expert at detecting organic compounds in rocks, has found them in Martian samples collected by the Curiosity rover.
    (Chris Gunn)

    These latest carbon-based organics were most likely bound up inside minerals, Eigenbrode said. Their discovery now is a function of having an oven on Mars that, for the first time, can get hot enough to break them apart.

    The larger molecules bring with them additional importance because, as Eigenbrode explained it, 75 to 90 percent of organic compounds are of this more complex variety. What’s more, she said that the levels at which the compounds are present, as well as where they were found, suggests a pretty radical conclusion: that they are a global phenomenon, most likely found around the planet.

    Her logic is that the overall geochemistry of Gale Crater as read by Curiosity instruments is quite similar to the chemistry of samples tested by earlier rovers at two other sites on Mars, Gusev Crater and Meridiani Planum.

    Many Mars scientists are comfortable with taking these parallel bulk chemistry readouts — the sum total of all the chemicals found in the samples — and inferring that much of the planet has a similar chemical makeup.

    Taking the logic a step further, Eigenbrode proposed to the assembled scientists that the signatures of carbon-based organics are also a global phenomenon.

    “I think it just might be,” she told the NAS workshop. “We’ll have to find out more, but I think there’s a good possibility.”

    That’s rather a jump — from the situation not long ago when no organics had been knowingly detected on Mars, to one where there’s a possibility they are everywhere.

    4
    The Sample Analysis on Mars instrument has the job of searching for, among other xxx, organics on Mars. And it seems to have succeeded, despite some major obstacles. (NASA/Goddard Space Flight Center)

    And actually, they should be found everywhere. Not only do organic molecules rain down from the sky embedded in asteroids and interstellar dust, but they can also be formed abiotically out of chemicals on Mars and, just possibly, can be the products of biological activity.

    The fact that Mars surely has had organics on its surface and elsewhere has made the non-detection of organics a puzzle. In fact, that conclusion of “no organics present” following the Viking landings in the mid 1970s set the Mars program back several decades. If there weren’t even organic compounds to be found, the thinking went, then a search for actual living creatures was pointless.

    As is now apparent, the Viking instrument used to detect organics was not sufficiently powerful. What’s more, the scientists working with it did not know about a particular chemical on the Martian surface that was skewing the results. Plus the scientists may well have misunderstood their own findings.

    First with the question of technological muscle. The oven associated with the search for organics is part of a Gas Chromatograph Mass Spectrometer (GCMS), and it heats and breaks apart dirt and rock samples for analysis of their chemical makeup. The oven on the Viking landers went up to 500 degrees C, a temperature where Curiosity was not finding signs of organics. But when the oven temperature was raised to 825 degrees C, the signs of organics were found.

    In addition, NASA’s Phoenix lander discovered in 2008 that the Martian soil contained the salt perchlorate, which when burned in a GCMS oven can mask the presence of organics. And finally, the Viking landers actually did detect organics in the form of simple chlorinated hydrocarbons. They were determined at the time to be contamination from Earth, but the same compounds have been detected by Curiosity, suggesting that Viking might actually have found Martian, rather than Earthly, organics.

    What makes carbon-based organic compounds especially interesting to scientists is that life is made of them and produces them. So one source of the organics in Martian samples could be biology, Eigenbrode said. But she said there were other potential sources that might be more plausible.

    Organics, for instance, can be formed through non-biological geothermal and hydrothermal processes on Earth, and presumably on Mars too. In addition, both meteorites and interstellar dust are known to contain organic compounds, and they rain down on Mars as they do on Earth.

    Eigenbrode said the organics being detected could be coming from any one source, or from all of them.

    Asked at the workshop what concentrations of organics were found, she replied with a smile that light will be shed on the question at next week’s American Geophysical Union meeting.

    The detection of a growing variety of organics on Mars adds to the conclusion already reached by the Curiosity team — that Mars was once much wetter, warmer and by traditional definitions “habitable.” That doesn’t mean that life ever existed there, but rather that what are considered basic basic conditions for life were present for many millions of years.

    Eigenbrode said that the detection of these carbon-based compounds is important in terms of both the distant past and the perhaps mid-term future.

    For the past, it means that organics in a substantial reservoir of water like the one at Gale Crater some 3.6 billion years ago could have been a ready source of energy for microbial life. The microbes would then have been heterotrophs, which get their nutrition from organic material. Autotrophs, simpler organisms, are capable of synthesizing their own food from inorganic substances using light or chemical energy.

    But Eigenbrode also sees the organics as potentially good news for the future — for possibly still living microbes on Mars and also for humans who might be trying to survive there one day.

    “Thinking forward, the organic matter could be really important for farming — an ready energy source provided by the carbon,” she said.

    Just what a human colony on Mars might need.

    See the full article here. .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Many Worlds

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

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

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

    About NExSS

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

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

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

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

     
  • richardmitnick 10:30 am on December 8, 2016 Permalink | Reply
    Tags: Mars Exploration, New evidence for a warmer and wetter early Mars,   

    From phys.org: “New evidence for a warmer and wetter early Mars” 

    physdotorg
    phys.org

    December 7, 2016
    No writer credit

    1
    This false-colour map, produced by the Mars Orbiter Laser Altimeter (MOLA), depicts the topography of the Martian surface. Hellas Basin, the large, dark blue region below the centre, has a diameter of 2300 km, and is one of the largest identified impact craters both on Mars and within the Solar System. It is thought to have formed some 4 billion years ago. Credit: MOLA Science Team

    A recent study from ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter (MRO) provides new evidence for a warm young Mars that hosted water across a geologically long timescale, rather than in short episodic bursts – something that has important consequences for habitability and the possibility of past life on the planet.

    ESA/Mars Express Orbiter
    ESA/Mars Express Orbiter

    NASA/Mars Reconnaissance Orbiter
    NASA/Mars Reconnaissance Orbiter

    Although water is known to have once flowed on Mars, the nature and timeline of how and when it did so is a major open question within planetary science.

    The findings follow an analysis of a region of relatively smooth terrain, called inter-crater plains, just north of the Hellas Basin. With a diameter of 2300 km, the Hellas Basin is one of the largest identified impact craters both on Mars and within the Solar System, and is thought to have formed some 4 billion years ago.

    “These plains on the northern rim of Hellas are usually interpreted as being volcanic, as we see with similar surfaces on the Moon,” said Francesco Salese of IRSPS, Università “Gabriele D’Annunzio”, Italy, and lead author on the new paper. “However, our work indicates otherwise. Instead, we found thick, widespread swathes of sedimentary rock.”

    Sedimentary and volcanic (igneous) rocks form in different ways – volcanic, as the name suggests, needs active volcanism driven by a planet’s internal activity, while sedimentary rock usually requires water. Igneous rock is created as volcanic deposits of molten rock cool and solidify, while sedimentary builds up as new deposits of sediment form layers that compact and harden over geologically long timescales.

    “To create the kind of sedimentary plains we found at Hellas, we believe that a generally aqueous environment was present in the region some 3.8 billion years ago,” said Salese. “Importantly, it must have lasted for a long period of time – on the order of hundreds of millions of years.”

    A volatile adolescence?

    There are a couple of key models for early Mars – both involve the presence of liquid water, but in vastly different ways.

    2
    This detailed geological map of the intercrater plains north of the Hellas basin was produced by Francesco Salese and colleagues using images from the Mars Express High-Resolution Stereo Camera (HRSC), the Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE), and Context (CTX) camera. The data from Mars Express and MRO allowed the scientists to explore the region’s appearance, topography, morphology, mineralogy, and age. More specifically, Mars Express imaging data allowed them to study the plains’ geology on a regional scale, providing context for the local-scale observations from MRO. Analysis of the map provides new evidence for a warm young Mars that hosted water across a geologically long timescale, rather than in short episodic bursts – something that has important consequences for habitability and the possibility of past life on the planet. Credit: Salese et al., 2016. J. Geophys. Res. Planets, 121, doi:10.1002/2016JE005039, Reused with permission of the American Geophysical Union

    Some studies suggest that Mars’ earliest days (the Noachian period, over 3.7 billion years ago) had a steadily warm climate, which enabled vast pools and streams of water to exist across the planet’s surface. This watery world then lost both its magnetic field and atmosphere and cooled down, transforming into the dry, arid world we see today.

    Alternatively, rather than hosting a warm climate and water-laden surface for eons, Mars may instead have only experienced short, periodic bursts of warmth and wetness that lasted for less than 10 000 years each, facilitated by a sputtering cycle of volcanism that intermittently surged and subsided across the years.

    Both scenarios could form some of the water-dependent chemistries and rock morphologies we see across Mars’ surface, and have significant consequences for Mars in both a geological sense – how the planet formed and evolved, whether its past has anything in common with Earth’s, and the composition and structure of its surface – and in terms of potential habitability.

    “Understanding if Mars had a warmer and wetter climate for a long period of time is a key question in our search for past life on the Red Planet,” said co-author Nicolas Mangold of CNRS-INSU, Nantes University, France.

    “If we can understand how the martian climate evolved, we’ll have a better understanding of whether life could have ever flourished, and where to look for it if it did. We can also learn much about rocky planets in general, which is especially exciting in this era of exoplanet science, and about our own planet – the same processes we think to have been important on a young Mars, such as sedimentary processes, volcanism, and impacts, have also been crucial on Earth.”

    From formation to erosion

    Salese and colleagues used imaging and spectro-imaging data from Mars Express and MRO to create a detailed geological map of the area around northern Hellas, taking advantage of so-called “erosional windows” – geological formations that act as natural “drill holes” down into the plains, revealing deeper material (examples include impact craters, grabens, and outcrops).

    These data showed the plains to be composed of an over 500-metre-thick band of flat, layered, light-coloured rock. The rock showed several characteristics typical of sedimentary deposition: box-work, which is a type of box-like mineral structure formed by erosion; cross-bedding, identified as layers of rock intersecting at different tilts and inclines; and planar stratification, which manifests as distinct, near-horizontal layers of rock that line up atop one another. These were in addition to large amounts of clays known as smectites.

    Clays are exciting chemicals, as they indicate that a wet and thus potentially habitable environment once existed at that location. Clays can also trap organic material and potentially preserve signs of life.

    “These characteristics suggest that the rock didn’t form from lava flow deposits but rather from sedimentary processes, which implies that the region once experienced warm and wet conditions for a relatively long time,” said Salese. “When the layered rock was deposited – during the Noachian period, around 3.8 billion years ago – its surroundings must have been soaked in water, with intense liquid circulation. We think it likely formed in a lake (lacustrine) or stream (alluvial) environment, or a combination of both.”

    The rock then underwent an intense period of volcanic erosion during the Hesperian period (3.7 to 3.3 billion years ago) and was covered by volcanic flows, creating the morphology we see today. The scientists estimate a minimum erosion rate for this time period of one metre per million years – one hundred times higher than the erosion rates estimated on Mars in the past 3 billion years.

    “This is further evidence of a prolonged period of active geological processes on the surface of early Mars,” added Mangold. “We can also extrapolate our finding to the rest of Mars and be confident we understand the evolution of the planet as a whole – we believe that the global climate conditions of Noachian Mars were sufficient to support significant liquid water.”

    Cosmic collaboration

    This study used data from Mars Express and MRO, which allowed the scientists to explore the region’s appearance, topography, morphology, mineralogy, and age. More specifically, Mars Express imaging data allowed Salese and colleagues to study the plains’ geology on a regional scale, providing context for the local-scale observations from MRO.

    The presence of rock morphologies or minerals that imply a wet history point towards possible habitability at that location in the past – something that is important in selecting landing sites and areas of interest for future robotic and potential human missions to Mars.

    “This work again demonstrates the importance of successful cooperation between different missions, and collaboration between ESA and NASA,” said Dmitri Titov, ESA Project Scientist for Mars Express. “No mission would be able to unveil the history of Mars alone. By using multiple spacecraft and different observation techniques, it’s possible to characterise all kinds of different geological processes on Mars in all their complexity, and gain a more complete view of Mars’ early days.”

    This finding is part of a series of efforts to understand Mars’ history and the planet as a whole, performed using Mars Express and other spacecraft – from studying Mars’ early climate by probing the evolution of large lakes that once existed across the planet’s surface, to observing Mars’ present-day weather (including mystery clouds and aurorae), and characterising the pockets of magnetism locked up within its crust.

    More information: Francesco Salese et al. A sedimentary origin for intercrater plains north of the Hellas basin: Implications for climate conditions and erosion rates on early Mars, Journal of Geophysical Research: Planets (2016). DOI: 10.1002/2016JE005039

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 10:56 am on December 4, 2016 Permalink | Reply
    Tags: , , , Mars Exploration   

    From ESA: “First views of Mars show potential for ESA’s new orbiter” 

    ESA Space For Europe Banner

    European Space Agency

    29 November 2016
    Håkan Svedhem
    ESA ExoMars TGO Project Scientist
    Email: hakan.svedhem@esa.int

    Markus Bauer
    ESA Science and Robotic Exploration Communication Officer
    Tel: +31 71 565 6799
    Mob: +31 61 594 3 954
    Email: markus.bauer@esa.int

    ESA’s new ExoMars orbiter has tested its suite of instruments in orbit for the first time, hinting at a great potential for future observations.


    Access mp4 video here .

    ESA/ExoMars
    ESA/ExoMars

    The Trace Gas Orbiter, or TGO, a joint endeavour between ESA and Roscosmos, arrived at Mars on 19 October. Its elliptical orbit takes it from 230–310 km above the surface to around 98 000 km every 4.2 days.

    ESA/ExoMars Trace Gas Orbiter
    ESA/ExoMars Trace Gas Orbiter

    It spent the last two orbits during 20–28 November testing its four science instruments for the first time since arrival, and making important calibration measurements.

    2
    First look at the atmosphere. Credit: ESA/Roscosmos/ExoMars/NOMAD/BISA/IAA/INAF/OU

    Data from the first orbit has been made available for this release to illustrate the range of observations to be expected once the craft arrives into its near-circular 400 km-altitude orbit late next year.

    TGO’s main goal is to make a detailed inventory of rare gases that make up less than 1% of the atmosphere’s volume, including methane, water vapour, nitrogen dioxide and acetylene.

    Of high interest is methane, which on Earth is produced primarily by biological activity, and to a smaller extent by geological processes such as some hydrothermal reactions.

    The two instruments tasked with this role have now demonstrated they can take highly sensitive spectra of the atmosphere. During the test observations last week, the Atmospheric Chemistry Suite focused on carbon dioxide, which makes up a large volume of the planet’s atmosphere, while the Nadir and Occultation for Mars Discovery instrument homed in on water.

    They also coordinated observations with ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter, as they will in the future.

    ESA/Mars Express Orbiter
    ESA/Mars Express Orbiter

    NASA/Mars Reconnaissance Orbiter
    NASA/Mars Reconnaissance Orbiter

    Complementary measurements by the orbiter’s neutron detector, FREND, will measure the flow of neutrons from the planet’s surface. Created by the impact of cosmic rays, the way in which they are emitted and their speed on arriving at TGO points to the composition of the surface layer, in particular to water or ice just below the surface.

    The instrument has been active at various times during the cruise to Mars and on recent occasions while flying close to the surface could identify the relative difference between regions of known higher and lower neutron flux, although it will take several months to produce statistically significant results.

    Similarly, the instrument showed a clear increase in neutron detections when close to Mars compared to when it was further away.

    The different capabilities of the Colour and Stereo Surface Imaging System were also demonstrated, with 11 images captured during the first close flyby on 22 November.

    At closest approach the spacecraft was 235 km from the surface, and flying over the Hebes Chasma region, just north of the Valles Marineris canyon system. These are some of the closest images that will ever be taken of the planet by TGO, given that the spacecraft’s final orbit will be at around 400 km altitude.

    The camera team also completed a quick first test of producing a 3D reconstruction of a region in Noctis Labyrinthus, from a stereo pair of images.

    4
    First ExoMars stereo reconstruction. Credit: ESA/Roscosmos/ExoMars/CaSSIS/UniBE

    Although the images are impressively sharp, data collected during this test period will help to improve the camera’s onboard software as well as the quality of the images after processing.

    “We are extremely happy and proud to see that all the instruments are working so well in the Mars environment, and this first impression gives a fantastic preview of what’s to come when we start collecting data for real at the end of next year,” says Håkan Svedhem, ESA’s TGO Project Scientist.

    “Not only is the spacecraft itself clearly performing well, but I am delighted to see the various teams working together so effectively in order to give us this impressive insight.

    “We have identified areas that can be fine-tuned well in advance of the main science mission, and we look forward to seeing what this amazing science orbiter will do in the future.”

    5
    ExoMars science orbit 1. Credit: ESA

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ESA50 Logo large

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: