Tag: Mars (page 1 of 5)

Pam Conrad: The NASA Astrobiologist Who Also Became a Minister

Pan Conrad on her last Sunday as rector of St. Albans Episcopal Church in Glen Burnie, Maryland. (Julian Lahdelma)

Science and religion so often seem to be in conflict, with the chasm between them widening all the time.

For many, the grounding of their religion is in faith and belief in powers beyond our understanding.  For people of science, the grounding is in empirical facts and measurements that can be tested to help explain our world.

The conflicts between science and religion have been many,  perhaps most intensely on issues including evolution, how life on Earth began and how our universe came to be.

The era of pioneering scientists being punished or hounded by religious leaders — think of Galileo, astrobiologist-before-his-time Giordano Bruno, Charles Darwin — is largely in the past.  But so too is the era when the most prominent natural scientists were profoundly religious people, such as Sir Isaac Newton, James Maxwell (who correctly theorized the nature of electromagnetism) and one of the 19th century physicist and scientific titan, Lord Kelvin.

The field of astrobiology presents innumerable issues where a scientific and religious focus certainly could clash.  Astrobiology is focused on the search for life beyond Earth which, if detected, could raise significant issues for some religious people.

The astrobiology effort is grounded in our scientific theories of how the universe began and evolved over its 13.6 billion years, so spiritual and religious views that once dominated thinking about these questions play little role.

And then there is the origin-of-life issue, which is also part of astrobiology and is, of course, an arena where scientific and religious views are often in conflict.

With so many divides between a scientific and a religious approach to astrobiological questions, it might seem that there is little room for overlap.

Conrad has worked on the characterization of biosignatures and the habitability of Mars, first at JPL and now at the Earth and Planets Laboratory at the Carnegie Institution of Science. She worked on the science team of the Curiosity rover on Mars and now she works with three instruments on the Perseverance rover at Jezero Crater, Mars. (NASA)

But then I spoke with the Rev. Pamela Conrad, who I knew from some years ago when we often talked about astrobiology and even took a trip to Death Valley together, where she helped me understand some of the science of life surviving in extreme environments and how to find it.… Read more

New Martian Surprise From The Curiosity Rover

NASA researchers found that waves on the surface of a shallow lake in Gale Crater stirred up sediment billions of years ago. That sediment eventually creating rippled textures left in rock. (NASA/JPLVCaltech/MSSS)

In its more than a decade of exploring Gale Crater on Mars, the rover Curiosity has found innumerable signs of the presence of long-ago water.

There have been fossil streams, alluvial fans, lakes shallow and deep, deltas and countless examples of rocks infiltrated and chemically transformed in the presence of water.  The picture of the crater as a watery environment in the warmer and wetter days of Martian history — 4 billion to 3 billion years ago — is well established.

Nonetheless. it still came as a wonder that the rover came across the entirely unexpected remains of fossilized ripples in a shallow lake bed.  What was even more surprising is that it was found in an area previously determined to have little likelihood of having ever been wet.

“Billions of years ago, waves on the surface of a shallow lake stirred up sediment at the lake bottom, over time creating rippled textures left in rock,” NASA said in a statement last week.

It was the first time such a feature has been discovered in Gale Crater, although the rover has passed through numerous fossil lake beds.

The Marker Band is a continuous dark, thin and hard layer running from left to right (but thinning out on the left) setting off the region of the rippled rock bed.   Both its composition and origins are not well understood. (NASA/JPL-Caltech)

One of the mission’s main goals has been to find out if this area in the southern highlands of Mars might have once been habitable for microbial life.

It was determined within the first two years of the rover’s time in Gale Crater that the crater was indeed once habitable based on the past presence of significant amounts of water and chemicals left behind by that long-departed water. Understanding the crater’s history of water has been a central goal of the mission.

The Curiosity team was thrilled by their new find.

“This is the best evidence of water and waves that we’ve seen in the entire mission,” said Curiosity project scientist Ashwin Vasavada. “We climbed through thousands of feet of lake deposits and never saw evidence like this.”

The rippled fossils are in an area set off by a black, hard-rock line called the “Marker Band.”… Read more

Tantalizing Organic Compounds Found on Mars

The NASA/ESA Perseverance rover on xxx. New findings tell of the presence of organic material — the building blocks of life — in several locations at Jezero Crater — for the first time found in igneous rock.  The long-ago environment when the organics were deposited were deemed to have been “habitable.” (NASA/JPL-Caltech/MSSS)

When searching for signs of ancient life on Mars, NASA scientists increasingly focus on organic material — the carbon-based compounds that are the building blocks of life.  Organics were found by the Curiosity rover in Gale Crater, and now new papers report they have also been identified by the instruments of the Perseverance rover in very different kinds of rock in Jezero Crater.

Unlike the Gale Crater organics that were found in sedimentary rocks, these newly found specimens are in igneous rocks — formed when molten rock cools and crystallizes — and are mixed with other compounds known to preserve organics well.

These rock samples are part of the NASA and European Space Agency Mars Sample Return mission, and so they could be brought to Earth in the future for more intensive study. Scientists are excited about what might some day be found.

The new findings about organics and the geology of Jezero Crater are part of a trio of articles in the journal Science published Wednesday.

The lead author of one of the papers, Michael Tice of Texas A&M University, gave this overview of what the Perseverance team is reporting:

“These three papers show that samples collected in the floor of Jezero should be able to tell us a lot about whether living organisms ever inhabited rocks under the surface of the crater over the past several billion years,”  he wrote to me.

The paper he led, Tice said, shows that small amounts of water passed through those rocks at three different times, and that conditions at each of those times could have supported life. “Even more importantly, minerals were formed from the water that are known to be able to preserve organic matter and even fossils on Earth.”

Different kinds of carbon-based organic compounds were viewed within a rock called “Garde” by SHERLOC, one of the instruments on the end of the robotic arm aboard the Perseverance rover. The rover used its drill grind away a patch of rock so that SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) could analyze its interior.

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Did Ancient Mars Life Kill Itself Off?

The study revealed that while ancient Martian life may have initially prospered, it would have rendered the planet’s surface covered in ice and uninhabitable, under the influence of hydrogen consumed by microbes and methane released by them into the atmosphere. (Boris Sauterey and Regis Ferrière)

The presence of life brings many unexpected consequences.

On Earth, for instance, when cyanobacteria spread widely in ancient oceans more than two billion years ago, their production of increasingly large amounts of oxygen killed off much of the other anaerobic life present at the day because oxygen is a toxin, unless an organism  finds ways to adapt.   One of the first global ices followed because of the changed chemistry of the atmosphere.

Now a group of researchers at the University of Arizona has modeled a similar dynamic that could have potentially taken place on early Mars.

As the group reports in the journal Nature Astronomy, their work has found that if microbial life was present on a wetter and warmer ancient Mars — as some now think  that it potentially was — then it would almost certainly have lived below the surface.  The rock record shows that the atmosphere would then have consisted largely of carbon dioxide and hydrogen, which would have warmed the planet with a greenhouse effect.

By using a model that takes into account how processes occurring above and below ground influence each other, they were able to predict the climatic feedback of the change in atmospheric composition caused by the biological activity of these microbes.

In a surprising twist, the study revealed that while ancient Martian life may have initially prospered, its chemical feedback to the atmosphere would have kicked off a global cooling of the planet by the methanogen’s use of the atmospheric hydrogen for energy and the production of methane as a byproduct.

That replacement of hydrogen with methane ultimately would render its surface uninhabitable and drive life deeper and deeper underground, and possibly to extinction.

“According to our results, Mars’ atmosphere would have been completely changed by biological activity very rapidly, within a few tens or hundreds of thousands of years,” said Boris Sauterey, a former postdoctoral student at the University of Arizona who is now a fellow at Sorbonne Université in Paris. .

“By removing hydrogen from the atmosphere, microbes would have dramatically cooled down the planet’s climate.”

Jezero Crater is where the Perseverance rover has been exploring since landing in early 2021.

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A Detailed New Mapping of Where Mars Once Had Plentiful Water

Measurements from the OMEGA instrument of European Space Agency’s Mars Express and NASA’s Mars Reconnaissance Orbiter’s CRISM spectrometer were used to map where formed-in-water minerals can found across Mars. This is an especially concentrated spot at Jezero Crater, where the Perseverance rover is located. (ESA)

NASA’s long-time motto for exploring Mars has been “Follow the water.”  That has changed some in recent years, as the presence of long-ago H2O has been confirmed in many locales around the planet.   Moving on, the motto today is more “Follow the organics” — the carbon-based building blocks of life — in the search for habitable environments and maybe signs of ancient life.

But water remains crucial to any discussion of habitability on Mars, and so a new set of global water maps from the European Space Agency, ten years in the making, is both useful and intriguing.

Specifically, the map shows the locations and abundances of these aqueous minerals — rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts.

And the message that the maps deliver, said planetary scientist John Carter, is that these hydrated minerals are common across many parts of the planet.

Ten years ago, planetary scientists knew of around 1, 000 water-altered outcrops on Mars, he said.  This made them interesting as geological oddities.

But the new map has reversed the situation, revealing hundreds of thousands of such areas in the oldest parts of the planet.

“This work has now established that when you are studying the ancient terrains in detail, not seeing these minerals is actually the oddity,” says Carter, an assistant professor at the Institut d’Astrophysique Spatiale (IAS) in  France.

Global map of hydrated minerals on Mars. (ESA)

Now, Carter said in a release, the big question is whether the water was persistent or confined to shorter, more intense episodes. While not yet providing a definitive answer, the new results certainly give researchers a better tool for pursuing the answer.

“I think we have collectively oversimplified Mars,” says Carter, who was lead author in a paper published in the journal Icarus.

He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period — roughly 3.5 billion to 4 billion years ago — then as the water gradually dried up salts were produced across the planet.

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Mars Was Once Wetter and Warmer And It Had Life-Essential Organic Carbon. Was There Enough for Life to Emerge?

Yellowknife Bay in Gale Crater, Mars, was extensively studied by the Curiousity rover in 2011-12 and was declared to have been “habitable” long ago.  But the amount of life-essential organic carbon at the site appeared to be low, and now has been measured in detail. (NASA)

In the early days of the Curiosity mission on Mars, scientists were excited by what they found in what was once a mud-flat they called Yellowknife Bay.  After months of drilling and testing, the mission team concluded that the site once had the roughly neutral water, an array of chemicals that could support metabolism and the organic carbon compounds needed for life.  So Yellowknife Bay and the surrounding Gale Crater were deemed to have once been “habitable.”

The finding of organic carbon was a major step forward because it is essential as a building block for the emergence of life as we know it.  The readings were clear that the organic carbon was present, but it has taken a decade to produce the first measurement of how much of the precious organic carbon was present.

The results, published late last month in the Proceedings of the National Academy of Sciences, show higher organic carbon levels than in some “low-life” environments on Earth.  But those levels are still quite reduced and point to an unwelcoming Mars even in an area declared to be habitable billions of years ago when Mars was wetter and warmer.

“Total organic carbon is one of several measurements that help us understand how much material is available as feedstock for prebiotic chemistry and potentially biology,” said Jennifer Stern of NASA’s Goddard Space Flight Center.

“We found at least 200 to 273 parts per million of organic carbon. This is comparable to or even more than the amount found in rocks in very low-life places on Earth, such as parts of the Atacama Desert in South America, and more than has been detected in Mars meteorites.”

The Atacama is one of the driest places on Earth, but it does support some life — bacteria under the surface of the desert and even some desert flowers in areas that experience fog.  Not surprisingly, NASA and other scientists often use the Atacama when they study conditions on ancient Mars.

The Atacama desert in Chile is one of the driest places on Earth and is often studied as a Mars analog. (Shudderstock)

This carbon data has been a long time coming.

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NASA’s Perseverance Rover on Mars; an Update

 

The composite images of “Delta Scarp” in Jezero Crater reveal that billions of years ago, when Mars had an atmosphere thick enough to support water flowing across its surface, Jezero’s fan-shaped river delta apparently experienced a late-stage flooding events that carried rocks and debris into it from the highlands well outside the crater. (RMI: NASA/JPL-Caltech/LANL/CNES/CNRS/ASU/MSSS).

NASA’s Perseverance rover has been on Mars for fifteen months now and is about to begin its trek into the fossil delta of Jezero Crater.  It’s a big deal for the mission, because the delta is where water once flowed long enough and strongly enough to smooth, round and move large rocks.

Since proof of the long-ago presence of water means the area was potentially habitable — especially a delta that spreads out into what were once calm rivulets — this is where the astrobiology goals of the mission come to the fore.

Or so the Perseverance team thought it would play out.

But the big surprise of the mission so far has been that the rover landed on igneous rock, formed in the Martian interior, spewed out and crystalized and solidified on the surface.

That Perseverance would land on igneous rock was always seen as a possibility, but a more likely outcome was landing on sedimentary rock as in  Gale Crater, where the Curiosity rover continues its decade-long explore. Sedimentary rock is laid down in layers in the presence of water.

Perseverance takes a selfie in Jezero. The rover is a twin of the Curiosity rover, but with some upgrades and new instruments (NASA/JPL-Caltech/MSSS)

As explained last week at the Ab-Sci-Con 2022 conference in Atlanta, the deputy program scientist for the mission — Katie Stack Morgan of NASA’s Jet Propulsion Lab — from the mission’s perspective the presence of both igneous and nearby sedimentary rock offers the best of both worlds.

While sedimentary rock is traditionally where scientists look for signs of ancient life, igneous rock can date the site more exactly and it can potentially better preserve any signs of early microbial life.

And in the context of Perseverance, the presence of accessible and compelling igneous formations provides for the diversity of rock samples called for in the Mars Sample Return effort — another central part of the rover’s mission.

“We did a lot of work with our different instruments to come to the conclusion that we landed on  igneous rock,” Stack Morgan later said in an interview. … Read more

“Tantalizing” Carbon Signals From Mars

This mosaic was made from images taken by the Mast Camera aboard NASA’s Curiosity rover on the 2,729th Martian day, or sol, of the mission. It shows the landscape of the Stimson sandstone formation in Gale crater. In this general location, Curiosity drilled the Edinburgh hole, a sample from which was enriched in carbon-12. (NASA/JPL-Caltech/MSSS.)

The rugged and parched expanses of Western Australia are where many of the oldest signs of ancient life on Earth have been found, embedded in the sedimentary rocks that have been undisturbed there for eons.  One particularly significant finding from the Tumbiana Formation contained a substantial and telltale excess of the carbon-12 isotope compared with carbon-13.

Since carbon 12 is used by living organisms, that carbon-12 excess in the rocks was interpreted to mean that some life-form had been present long ago (about 2.7 billion years) and left behind that “signature”  of its presence. What was once a microbial mat that could have produced the carbon-12 excess was ultimately found nearby.

After nine years of exploring Gale Crater on Mars, scientists with NASA’s Curiosity rover have collected a substantial number of rock samples that they have similarly drilled, pulverized, gasified and analyzed.

And as explained in an article in the Proceedings of the National Academy of Science (PNAS,) researchers have found quite a few Martian specimen that have the same carbon-12 excesses as those found in Western Australia.

Paul Mahaffy of NASA’s Goddard Space Flight Center, long-time principal investigator for the instrument that found the carbon-12 excess on Mars, called the results “tantalizingly interesting.”

And the lead author of the PNAS paper, Christopher House of Penn State University, said that “On Earth, processes that would produce the carbon signal we’re detecting on Mars are biological.”  Like from Western Australia and elsewhere.

So something unusual and important has been discovered. But exactly what it is and how it came to be remains very much a work in progress.

Perhaps biology did play a role, the team writes.  If so, it would involve ancient bacteria in the Martian surface that would have produced a unique carbon signature when they released methane into the atmosphere. Ultraviolet light would have then converted that gas into larger, more complex molecules that would rain down and become part of Martian rocks.

Scientists with NASA and European Mars missions traveled to the Western Australian Outback to hone their research techniques before their missions launched.

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A Huge Watery Reservoir May Lie Beneath the Surface of The “Grand Canyon” of Mars

The Valles Marineris in equatorial Mars and is one of the the largest canyon in the solar system.  It is surpassed in length only by the rift valleys of Earth. (NASA)

That early Mars was much wetter and warmer than it is today has been well established by numerous missions.  Water ice is visible at the poles and many fossil rivers have been found in the southern highlands of Mars.  The Curiosity rover found as well that the large crater where it landed — Gale Crater – once had a lake and in-flowing streams.

But the presence of water, or proof that water once flowed, has been missing in the equatorial latitudes  of the planet.

However, now a paper based on data from the European/Russian Trace Gas Orbiter (TGO) strongly suggests that the Candor Chasma, located near the heart of the massive canyon system called Valles Marineris, has either large deposits of a kind of permafrost water ice just below its surface or of rocks formed in water and now containing that H2O in their structure.

The article to appear in the journal Icarus says that the discovery of large amounts of hydrogen in the region speaks of this aqueous  past.

“We found a central part of Valles Marineris to be packed full of water – far more water than we expected,” Alexey Malakhov, of the Russian Space Research Institute and a co-author of the study, said in a statement.

“This is very much like Earth’s permafrost regions, where water ice permanently persists under dry soil because of the constant low temperatures.”

 

Valles Marineris, seen at an angle of 45 degrees to the surface in near-true color and with four times vertical exaggeration. The image covers an area of about 400,000 square miles. The largest portion of the canyon, which spans right across the image, is known as Melas Chasma. Candor Chasma is the connecting trough immediately to the north. The digital terrain model was created from 20 images taken by the High Resolution Stereo Camera of the Mars Express Orbiter. (ESA)

Valles Marineris is 10 times longer and 4 times deeper than our Grand Canyon.  Geologists have theorized that Valles Marineris began to open along geological faults about 3.5 billion years ago. The faulting may have been caused by the tectonic activity that accompanied the growth of the giant volcanoes in Tharsis, lying just to the west.Read more

Sample Return from Mars Begins in Earnest

This image taken by NASA’s Perseverance rover on Sept. 7, 2021 shows two holes where the rover’s drill obtained chalk-size samples from a rock nicknamed “Rochette.” They are the first physical manifestations of the NASA’s long-planned Mars Sample Return Mission. (NASA/JPL-Caltech.)

For the first time ever, a sample of pulverized rock from another planet has been drilled, collected and stored for eventual delivery to the highest-tech labs on Earth.

Yes, a storehouse of rocks were collected on the moon by Apollo astronauts and delivered to Houston, and some small samples of two asteroids and one comet were snatched by three spacecraft (two Japanese and one American) and their contents were brought here for study.

But never before has the surface of another planet been the source of precious extraterrestrial material that some day, if all goes well, will be received on Earth for intensive analysis.

The feat was accomplished by the team that operates the Perseverance rover on Mars.  After an unsuccessful effort to drill what turned out to be a very soft rock in August , the rover drill succeeded in digging into a briefcase-sized hard volcanic rock twice this month and pulling out samples to be tubed and stored for later pick-up by a different mission.

That next step isn’t scheduled for another half decade and the samples would not arrived on Earth until well after that.  But a long-dreamed and highly-ambitious effort to bring some of Mars to Earth (called Mars Sample Return) has now formally begun.

“This is a truly historic achievement, the very first rock cores collected on another terrestrial planet — it’s amazing,” Meenakshi Wadhwa, Mars sample return principal scientist at NASA’s Jet Propulsion Laboratory, said during a news conference held Friday

“In our science community, we’ve talked about Mars sample return for decades,” Wadhwa said. “And now it’s actually starting to feel real.”

Perseverance’s first cored-rock sample of Mars is seen inside its titanium container tube in this image taken by the rover’s Sampling and Caching System Camera, known as CacheCam. (NASA/JPL-Caltech)

The press conference was a victory lap of sorts for leaders of a team with many members who have worked eight to ten years for this moment.  Lori Glaze, NASA’s director of the Planetary Science Division, also called it an historic achievement –the culmination of advances pioneered by many other NASA missions to Mars and elsewhere and a milestone for NASA’s Mars program.… Read more

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