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What events could have to happen to Mars (which is thought to once look like Earth) that may have depleted the atmosphere and erase all proof of life ever existing at least on the surface?
I know an asteroid could melt the planet but could there have been an event that could wipe the surface while leaving deposits under the ground intact?
There is no proof that Mars melted but there is proof that there at least was oceans.
Where did Mars water go?
No molten core iron -> no magnetosphere -> solar wind strips atmosphere.
Without atmosphere to cycle in exposed water also leaves.
Why did Mars freeze solid & Earth has not (yet).
- is further from sun
- smaller means less volume to hold heat
- Earth may have the iron cores from two planets (moon forming impact)
- Radioactive decay?
On oil, possibly.
If there was life there and it colonized the land and it found it needed to create a scaffolding structure to compete for photons such as ligand as happened here, and there were several hundred millions years until other life there figured out how to digest those ligands then there would be a layer there like our Carboniferous era in which a large amount of carbon is sequestered underground.
But chances are vanishingly slim.
If there was life there it most likely
- recycled carbon just as we have here for all time except that little blip* after trees showed up and before bacteria figured out how to digest them.
- did not survive long enough to need to compete for photons by growing very tall
(*) 300,000,000 / 4,300,000,000 is about 1/14th of life on earth's history.
Mars may still be volcanically active, study finds
Evidence of what may be the youngest eruption seen yet on Mars suggests the Red Planet may still be volcanically active, raising the possibility it was recently habitable, a new study finds.
Most volcanism on Mars occurred between 3 billion and 4 billion years ago, leaving behind giant monuments such as Olympus Mons, the tallest mountain in the solar system. At 16 miles (25 km) high, Olympus Mons is about three times as tall as Mount Everest, Earth's highest mountain.
Previous research suggested the Red Planet may still have flared with smaller volcanic eruptions as recently as 2.5 million years ago. Now scientists have found evidence that Mars may still be volcanically active, with signs of an eruption within the past 50,000 years or so.
"This being the youngest documented volcanic eruption on Mars, the potential that Mars could potentially be volcanically active at present is exciting," study lead author David Horvath, a planetary scientist now at the Planetary Science Institute in Tucson, Arizona, told Space.com.
Using data from satellites orbiting Mars, researchers analyzed relatively featureless equatorial plains of a region known as Elysium Planitia. They discovered a previously unknown smooth dark volcanic deposit about 8 miles (13 kilometers) wide, covering an area slightly larger than Washington, D.C. It surrounds a volcanic fissure about 20 miles (32 km) wide, one of the cracks making up the fissure system known as Cerberus Fossae.
"I first noticed this volcanic deposit when I was looking over some images of this region. I had looked at this area many times before but somehow had always overlooked this feature," study senior author Jeff Andrews-Hanna, a planetary scientist at the University of Arizona at Tucson, told Space.com. "Once this odd dark deposit centered on a volcanic fissure came to my attention, I knew it was telling us something important."
Specifically, this deposit looked unlike anything else found in the region, or indeed on all of Mars, Andrews-Hanna said. Instead, it more closely resembled features created by older volcanic eruptions on the moon and Mercury.
Most signs of volcanism previously seen in Elysium Planitia and elsewhere on Mars consisted of lava flowing across the surface, similar to recent eruptions in Iceland. However, this newfound eruption looks different &mdash it appears to be a relatively fresh deposit of ash and rock on top of surrounding lava flows.
This volcanic deposit may be the most recent seen yet on Mars, the scientists noted. "If we were to compress Mars' geologic history into a single day, this would have occurred in the very last second," Horvath said in a statement.
The researchers found the properties, composition and distribution of material from the eruption match what they would expect from a pyroclastic eruption &mdash an explosive outburst of magma driven by expanding gases, not unlike the opening of a shaken can of soda. On Earth, deadly avalanches of scalding ash, toxic gas and pulverized rock from pyroclastic eruptions, known as pyroclastic flows, entombed the ancient Roman cities of Pompeii and Herculaneum after Mount Vesuvius erupted in 79 AD.
"This eruption could have spewed ash as high as 10 kilometers (6 miles) into the Martian atmosphere," Horvath said in the statement.
Although there are numerous examples of explosive volcanism on Mars, those occurred long ago. It is possible such pyroclastic deposits were once more common, but most have eroded or gotten buried, Horvath said.
The newfound volcanic deposit is located about 1,000 miles (1,600 km) from NASA's InSight lander, which has investigated tectonic activity on Mars since 2018. Two Marsquakes InSight detected in the region originated around Cerberus Fossae.
"We now know that this region is both the most volcanically and seismically active area on the planet today," Andrews-Hanna said.
Previous research suggested magma might still be moving deep underground the region around Cerberus Fossae.
"If lava was erupting to the surface only 50,000 years ago, and the area is still rumbling with seismicity today, that means that it could erupt again," Andrews-Hanna said.
One potential mechanism driving this eruption was gases trapped in magma, said study co-author Pranabendu Moitra, a research scientist at the University of Arizona. Another was contact between magma and permafrost, with ice in the permafrost melting to water, mixing with the magma, and then vaporizing, triggering a violent explosion, he added.
Intriguingly, this newfound eruption also happened only 6 miles (10 km) from the youngest large impact crater on Mars &mdash a meteor crater 6 miles (10 km) wide named Zunil. "The ages of the eruption and the impact are indistinguishable, which raises the possibility, however speculative, that the impact actually triggered the volcanic eruption," Moitra said in the statement.
Prior work found that on Earth, seismic waves from large quakes can force magma stored beneath the surface to erupt. The collision that created Zunil could potentially have shaken Mars like an earthquake, triggering an eruption, Moitra suggested.
"To be clear, we cannot state that the eruption was triggered by an impact &mdash only that the timing and magnitude are right," Andrews-Hanna said.
These new findings raise the possibility the warmth from recent volcanic activity could have made the Red Planet more habitable to life as we know it. Magma rising from deep underground could have melted ice near the surface, which could have provided favorable conditions for microbial life fairly recently.
"This does not necessarily confirm past life on Mars, but does imply an environment conducive to habitability," Horvath said.
The big question the scientists now have, Andrews-Hanna said, is "why is this particular area such a hotspot for activity on Mars?"
"Mars has a number of giant volcanoes, including nearby Elysium Mons, but this eruption and the volcanic fissures it is associated with are in an otherwise featureless plain," Andrews-Hanna added. "Is this area underlain by a plume of hot mantle material? Will the next great Martian volcano rise from this spot?"
The scientists detailed their findings online April 21 in the journal Icarus.
Air of Uncertainty
Researchers have long struggled to explain how liquid water could have surged across the surface of Mars. Today, its atmosphere is thin, with pressures too low to keep liquid water from boiling away, even at the planet’s typical low temperatures. In the past, a denser atmosphere could have increased the pressure to keep liquid water from becoming a gas. Over the 4.5 billion years since the solar system formed, that gas could have gradually been lost to space, the small planet’s gravitational pull too weak to hold onto its atmosphere. The loss of an atmosphere swung Mars from a potentially habitable environment to a barren wasteland. “It’s the greatest environmental disaster we know of,” says Edwin Kite, who studies habitability, at the University of Chicago, IL.
“Right now, carbon dioxide and hydrogen is the most promising greenhouse combination to warm early Mars.”
In the decades since the earliest missions set Mars in their sites, researchers have struggled to nail down the details of planet’s early atmosphere. An atmosphere warm enough to hold onto liquid water, or even frozen snow, requires just the right cocktail of gases, and trying to build the environment in simulations continues to puzzle researchers.
“Right now, carbon dioxide and hydrogen is the most promising greenhouse combination to warm early Mars,” says Ramses Ramirez, of the Tokyo Institute of Technology, Japan. Ramirez and his colleagues used a two-dimensional model with these gases to create a planet with typical temperatures above the freezing point of water.
The model also estimates rainfall runoff across different latitudes of the planet. They tested it across three different-sized oceans, with larger oceans producing more precipitation. The runoff rates for the largest ocean were just enough to produce the observed features. This ocean would have covered up to a third of the planet's surface.
Crucially, the researchers determined that even such a large ocean does not give Mars a moist, warm Earth-like climate. Instead, it results in cool, semi-arid conditions.
Mars Could Still Be Volcanically Active, Raising Questions About Recent Habitability
Mars has the highest mountain in the solar system, Olympus Mons. It is an extinct volcano three times the size of Everest, a huge monument to the incredible volcanic past of the planet. But perhaps the past is not as distant as we previously believed. Observations have so far suggested that no volcanoes have occurred on Mars for at least a few million years.
A new paper published in Icarus reports that some of the evidence is controversial. Astronomers have found a small region that appears to be a volcanic deposit in the Cerberus Fossae fissures system. The team believes that these deposits could be 220,000 years old and less than 50,000 years old. If it does, volcanic activity could occur today, Tuesday. Lead author Dr David Horvath, from the Planetary Science Institute, said in a statement, “This feature is a mysterious dark deposit. It has a high thermal inertia over a slightly larger area than Washington DC. This feature is similar to the dark spots on the moon and Mercury was proposed as an explosive volcanic eruption.”
“It may be the youngest volcano ever recorded on Mars. If we could compress the geological history of Mars in a day, it would happen at the very last second. The eruption probably left ashes in the atmosphere up to 10 kilometers (6.2 miles) away. Definitely impressive, but the team sees it as the latest rate of Martian volcano. It said the most powerful marsquakes spot identified by NASA Insight was Cerberus Fossae. While not sure, there may be a link between the two.
“The sheer age of this deposit raises the possibility that Mars may still have volcanic activity, and that the most powerful marsquakes detected by NASA’s Insight site have been inspired by Cerberus Fossae, which is interesting.” It will be harder to stay close to the surface of Mars in the long run, and therefore a deeper mathematical source will be needed to create this explosion.” As usual there is a question to answer when something unexpected is found on Mars. Could this hinder or help the possibility of life on the Red Planet? Volcanic activity will certainly help. Ascending magma can keep the region at a mild temperature it can melt underground ice deposits as well as create conditions conducive to microbial life.
Curiosity Finds Organic Molecules That Could Have Been Produced by Life on Mars
What do coal, crude oil, and truffles have in common? Go ahead. We’ll wait.
The answer is thiophenes, a molecule that behaves a lot like benzene. Crude oil, coal, and truffles all contain thiophenes. So do a few other substances. MSL Curiosity found thiophenes on Mars, and though that doesn’t conclusively prove that Mars once hosted life, its discovery is an important milestone for the rover. Especially since truffles are alive, and oil and coal used to be, sort of.
A quote from NASA’s Curiosity website reminds us what the rover’s mission is: “Curiosity was designed to assess whether Mars ever had an environment able to support small life forms called microbes. In other words, its mission is to determine the planet’s ‘habitability.’ ”
A pair of scientists from Berlin’s Technical University thinks that the thiophenes Curiosity found on Mars could be a signature from early Martian life. If they’re right, then Mars was, at one time, inhabited by simple life forms. They’ve presented their findings in a new paper.
The pair are Dirk Schulze-Makuch and Jacob Heinz. Schulze-Makuch is also an astrobiologist at Washington State University. Their paper is titled “Thiophenes on Mars: Biotic or Abiotic Origin?” It’s published in the journal Astrobiology.
MSL Curiosity found the thiophenes in Martian sediments. It’s one of a number of interesting molecules found on Mars that might have a biotic origin. Thiophenes can also have an abiotic origin through diagenesis, which are physical and chemical changes that take place as sediments become sedimentary rock.
Sedimentary rocks on Mars, investigated by NASA’s Curiosity Mars rover. Thiophenes can be produced by biotic processes, or by abiotic processes, like when sediment becomes sedimentary rock. By NASA/JPL-Caltech/MSSS – Catalog page · Full-res (JPEG · TIFF), Public Domain, https://commons.wikimedia.org/w/index.php?curid=30263203
In order to find the thiophenes in the Martian sediments, Curiosity had to first heat the sample above 500 Celsius. Then Curiosity examined it with the SAM (Sample Analysis at Mars) instrument. SAM analyzed the gases coming off the sample using gas chromatography-mass spectrometry. SAM is actually three instruments in one, and together they search for organic chemicals.
“We identified several biological pathways for thiophenes that seem more likely than chemical ones, but we still need proof,” Dirk Schulze-Makuch said in a press release. “If you find thiophenes on Earth, then you would think they are biological, but on Mars, of course, the bar to prove that has to be quite a bit higher.”
Thiophenes have a structure that suggests a possible biotic origin. They have four carbon atoms and a single sulfur atom arranged in a ring, with hydrogen atoms. Hydrocarbons are essential elements in organic chemistry, and hydrocarbon molecules containing atoms of sulfur are an important part of the study of organic chemistry.
The thiophene molecule. Image Credit: By Jynto – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11357639
There are non-biological sources of thiophenes. They can be created by meteor impacts, and by a process called thermochemical sulfate reduction, where compounds are heated above 120 Celsius (248 F).
But it’s the biological sources of thiophenes that are the most interesting. In the distant past, perhaps about 3 billion years ago, Mars was a much different place. It likely had a warm and wet environment that could’ve harbored life. Those ancient bacteria could’ve facilitated a sulfate reduction process biologically, which resulted in the thiophenes that Curiosity detected.
Technology moves quickly. Curiosity was much more advanced than its predecessors Spirit and Opportunity. It uses technology that breaks large molecules down into smaller molecules for analysis. But when the next Mars rover, the ESA’s ExoMars mission, arrives on the red planet, it’ll bring even more advanced technology.
ExoMars’ MOMA (Mars Organic Molecule Analyzer) is the premier astrobiology instrument on the ExoMars rover, and also the largest instrument. It’s a little more refined than Curiosity’s instrument, and it doesn’t rely on fragmentation to study molecules. MOMA will allow the collection and study of larger molecules.
The ESA’s ExoMars rover will land on Mars in 2021 and continue the search for evidence of ancient life on Mars. Credit:ESA
MOMA will use the concept of homochirality to identify molecules as either biotic or abiotic, something that MSL Curiosity can’t do. Homochirality is a property of amino acids and sugars. Many of the organic molecules necessary for life, including amino acids and sugars, can come in both left-handed and right-handed types, referred to as their chirality.
In Earth life, 19 of the 20 amino acids are homochiral and left-handed, while sugars, which are part of RNA and DNA, are homochiral and right-handed. Homochirality is essential for an efficient metabolism. But the same chemicals produced in a laboratory will have equal abundances of left-handed and right-handed types. The basic idea is that if we find homochiral building blocks of life, they likely have a biological source.
Life’s molecules need to able to “shake hands” with each other in order to function. People shake hands right-to-right, or maybe left-to-right. It’s not possible to shake right-to-left, or vice versa. Image Credit: ESA
Isotope ratios can also differentiate between the same atoms with either biotic or abiotic origins. Schulze-Makuch and Heinze, the authors of this paper, think that some of the data from the ExoMars rover should be used to also look for isotopes of carbon and sulfur. In particular, the lighter isotopes of both. They think that’s where we’re most likely to find a biological origin.
“Organisms are ‘lazy.’ They would rather use the light isotope variations of the element because it costs them less energy,” Schulze-Makuch said.
Lifeforms tend to alter the balance between light isotopes and heavy isotopes of the elements they produce. That ratio is different than the ratio in the same elements in their building blocks. That’s a “tell-tale sign of life” according to Schulze Makuch.
The discussion over life on Mars has been ongoing for decades. When the Viking landers were on Mars in 1976, they conducted the very first in-situ measurements, looking for organic compounds. What they found is still somewhat controversial today, because no lab experiments have been able to completely recreate those results. However, it’s widely believed in the scientific community that the Viking findings can be explained by abiotic sources.
The late, great Carl Sagan stands next to a model of the Viking lander. Credit: NASA
The ExoMars rover is our next step in understanding ancient Mars’ habitability. Its experimental results may bring us one step closer to knowing definitively if Mars once hosted life. But it might not get us all the way to that conclusion, unfortunately.
“As Carl Sagan said ‘extraordinary claims require extraordinary evidence,’” Schulze-Makuch said. “I think the proof will really require that we actually send people there, and an astronaut looks through a microscope and sees a moving microbe.”
Active volcanoes on Mars today? If so, they may point to Mars habitability
Oblique view of Cerberus Fossae, a tectonic fracture in the Elysium Planitia region of Mars. A new study of young lava flows surrounding it suggests that this area might still be volcanically active today, underground. Image via ESA/ DLR/ FU Berlin.
Mars has some of the largest volcanoes in the solar system, but they’ve apparently been inactive for millions of years. No plumes of ash or flowing streams of lava are seen on Mars today. But just how long ago were the last great Martian eruptions? That has been a matter of some debate among planetary geologists, and now scientists at the University of Arizona (UA) have announced new evidence for recent – geologically speaking – explosive volcanism in the Elysium Planitia region of Mars. According to the new findings, eruptions there may have occurred as recently as 53,000 years ago, which is a blink of an eye relative to Mars’ total age of about 4.6 billion years (same as Earth’s). According to these scientists, this finding could mean Mars is still volcanically active even today, at least underground. And, if it is, this finding may point to recent conditions of habitability on Mars.
Prior to this new work, the most recent eruptions known on Mars happened about 2.5 to 500 million years ago.
The intriguing findings were submitted to arXiv on November 11, 2020, for publication in the peer-reviewed journal Icarus.
Overhead view of Cerberus Fossae, with the mantling unit of younger lava flows surrounding it. Image via Horvath et al./ Cornell University.
The evidence comes from the study of a volcanic lava deposit distributed symmetrically around a segment of the Cerberus Fossae fissure system in Elysium Planitia, called the “mantling unit.”
The researchers say it is probably the youngest such deposit yet found on Mars. It is similar to pyroclastic flows – fluidized masses of rock – on the moon and Mercury, but sits on top of older lava flows and has a thickness of tens of centimeters.
By counting the number of impact craters visible in the area, the researchers, led by David Horvath at UA, say these eruptions are estimated to have happened only 53,000 to 210,000 years ago. That’s like yesterday in geological terms.
Elysium Planitia is also where NASA’s InSight lander touched down on November 26, 2018. Since then, the probe has recorded hundreds of marsquakes in the planet’s subsurface with its Seismic Experiment for Interior Structure (SEIS) instrument, proving that Mars is still seismically active. As of last February, it was reported that over 450 seismic signals had been detected, up to the equivalent of magnitude 4 on the earthly Richter Scale.
David Horvath at the University of Arizona, lead author of the new study. Image via University of Arizona.
Some of those quakes were detected near or at Cerberus Fossae, the location of the young lava deposits. Could there be a connection? Mars doesn’t have tectonic plates like Earth does, so those quakes are more similar to those in the middle of continents on Earth rather than at plate boundaries. Whether there is any relation to current volcanic activity isn’t known, but based on the new findings of young lava flows, it certainly seems possible. From the paper:
Given the young age of the deposit, it is possible that the deeper magma source that fed the deposit could still be active today and could generate seismicity observable by the Seismic Experiment for Interior Structure (SEIS) instrument on the Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) lander (Lognonné et al., 2019). Seismicity related to magma transport and chamber pressurization has been linked to active volcanism on Earth (e.g., Battaglia et al., 2005 Grandin et al., 2012 Carrier et al., 2015). Magma-induced seismicity along rift zones can result in small to moderate earthquake magnitudes (Mw < 6). Dike-induced faulting and seismicity (Rubin & Gillard, 1998 Taylor et al., 2013) associated with this young magmatic activity is also possible.
There is also a possibility that current volcanic activity, if proven, could help explain the presence of methane in Mars’ atmosphere. Various telescopes, orbiters and the Curiosity rover have all detected the gas in small quantities, which on Earth is produced mostly by microbes as well as some from geologic activity. Scientists still don’t know the source of the Martian methane, but even if it is only from geological activity, that could still have implications for biology, since it would require liquid water-related chemical reactions (serpentinization) below ground.
The landing site of NASA’s InSight lander in Elysium Planitia and its proximity to the tectonic fissure system Cerberus Fossae. The probe has detected hundreds of marsquakes, including near Cerberus Fossae, which may be related to subsurface volcanic activity. Image via J.T. Keane/ Nature Geoscience/ NASA. Landslides within Cerberus Fossae, caused by marsquakes. Image via NASA/ JPL-Caltech/ University of Arizona.
Geologically recent near-surface magmatic activity in Elysium Planitia, combined with evidence for recent groundwater-sourced floods (Burr et al., 2002 Head et al., 2003), which may have been triggered by dike intrusions (Hanna & Phillips, 2006), raises important implications regarding the subsurface habitability on Mars. Dike-induced melting of ground ice and hydrothermal circulation could generate favorable conditions for recent or even extant habitable environments in the subsurface. These environments would be analogous to locations on Earth where volcanic activity occurs in glacial environments such as Iceland, where chemotrophic and psychrophilic (i.e., cryophilic) bacteria thrive (Cousins & Crawford, 2011). Subsurface microbial communities found in basaltic lavas on Earth (McKinley et al., 2000) are also aided by hydrothermal circulation of groundwater through porous basalt (Storrie-Lombardi et al., 2009 Cousins & Crawford, 2011). Recent or ongoing magmatic activity on Mars could also provide a source of transient methane releases to the atmosphere (Formisano et al., 2004 Fonti & Marzo, 2010) through direct volcanic outgassing or, more likely, serpentinization reactions (Atreya et al., 2007).
The possibility that Mars is still volcanically active is exciting, since it would overturn long-held assumptions that the planet has been geologically dead for the most part for billions of years. It could also create habitable environments below the surface for Martian microorganisms, which would be even more exciting. Mars may not be as dead or dormant as we thought it was, perhaps in more ways than one.
Bottom line: A new study of geologically young lava flows suggests that Mars may still be volcanically active today.
NASA Rover Finds Conditions Once Suited for Ancient Life on Mars
An analysis of a rock sample collected by NASA's Curiosity rover shows ancient Mars could have supported living microbes.
PASADENA, Calif. -- An analysis of a rock sample collected by NASA's Curiosity rover shows ancient Mars could have supported living microbes.
Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon -- some of the key chemical ingredients for life -- in the powder Curiosity drilled out of a sedimentary rock near an ancient stream bed in Gale Crater on the Red Planet last month.
"A fundamental question for this mission is whether Mars could have supported a habitable environment," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at the agency's headquarters in Washington. "From what we know now, the answer is yes."
Clues to this habitable environment come from data returned by the rover's Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments. The data indicate the Yellowknife Bay area the rover is exploring was the end of an ancient river system or an intermittently wet lake bed that could have provided chemical energy and other favorable conditions for microbes. The rock is made up of a fine-grained mudstone containing clay minerals, sulfate minerals and other chemicals. This ancient wet environment, unlike some others on Mars, was not harshly oxidizing, acidic or extremely salty.
The patch of bedrock where Curiosity drilled for its first sample lies in an ancient network of stream channels descending from the rim of Gale Crater. The bedrock also is fine-grained mudstone and shows evidence of multiple periods of wet conditions, including nodules and veins.
Curiosity's drill collected the sample at a site just a few hundred yards away from where the rover earlier found an ancient streambed in September 2012.
"Clay minerals make up at least 20 percent of the composition of this sample," said David Blake, principal investigator for the CheMin instrument at NASA's Ames Research Center in Moffett Field, Calif.
These clay minerals are a product of the reaction of relatively fresh water with igneous minerals, such as olivine, also present in the sediment. The reaction could have taken place within the sedimentary deposit, during transport of the sediment, or in the source region of the sediment. The presence of calcium sulfate along with the clay suggests the soil is neutral or mildly alkaline.
Scientists were surprised to find a mixture of oxidized, less-oxidized, and even non-oxidized chemicals, providing an energy gradient of the sort many microbes on Earth exploit to live. This partial oxidation was first hinted at when the drill cuttings were revealed to be gray rather than red.
"The range of chemical ingredients we have identified in the sample is impressive, and it suggests pairings such as sulfates and sulfides that indicate a possible chemical energy source for micro-organisms," said Paul Mahaffy, principal investigator of the SAM suite of instruments at NASA's Goddard Space Flight Center in Greenbelt, Md.
An additional drilled sample will be used to help confirm these results for several of the trace gases analyzed by the SAM instrument.
"We have characterized a very ancient, but strangely new 'gray Mars' where conditions once were favorable for life," said John Grotzinger, Mars Science Laboratory project scientist at the California Institute of Technology in Pasadena, Calif. "Curiosity is on a mission of discovery and exploration, and as a team we feel there are many more exciting discoveries ahead of us in the months and years to come."
Scientists plan to work with Curiosity in the "Yellowknife Bay" area for many more weeks before beginning a long drive to Gale Crater's central mound, Mount Sharp. Investigating the stack of layers exposed on Mount Sharp, where clay minerals and sulfate minerals have been identified from orbit, may add information about the duration and diversity of habitable conditions.
NASA's Mars Science Laboratory Project has been using Curiosity to investigate whether an area within Mars' Gale Crater ever has offered an environment favorable for microbial life. Curiosity, carrying 10 science instruments, landed seven months ago to begin its two-year prime mission. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the project for NASA's Science Mission Directorate in Washington.
Volcanoes on Mars Might Still be Active
Back in March, NASA’s InSight lander detected two large quakes from a geologically active region of Mars called the Cerberus Fossae. Now, using imagery from the Mars Reconnaissance Orbiter, which circles the red planet at an altitude of about 300km, researchers have discovered that the Cerberus Fossae region holds the most recent evidence of volcanic activity ever seen on Mars.
The newly observed volcanic deposit could have been created as recently as 46,000 years ago, though outer estimates suggest that, at the oldest, it might be 200,000 years old. In either case, on geological time scales, this is a very young deposit. Most of the volcanic rock elsewhere on Mars is orders of magnitude more ancient, forming during a period of heavy geological activity between 3 and 4 billion years ago. More recent volcanic eruptions occurred with regularity on Mars up to about 3 million years ago, but until now, we have never seen any evidence of volcanism that can be dated in the thousands of years. This new deposit is unique. As lead researcher David Horvath from the Planetary Science Institute explains, “if we were to compress Mars geologic history into a single day, this would have occurred in the very last second.”
The dark splotch extending to either side of this fissure in the Cerberus Fossae region marks the most recent volcanic activity ever found on Mars. It is about 13km across. Image Credit: NASA/JPL/MSSS/The Murray Lab.
The eruption that created the deposit appears to have been explosive in nature, with a pyroclastic cloud that could have reached as high as 6km. The dark layer of ash and volcanic material leftover from the explosion now covers a 13km wide region on either side of one of the large fissures from which the Cerberus Fossae takes its name.
Most volcanic rock found on Mars today is the result of lava flowing slowly across the surface. Explosive volcanism like this seems much rarer, though its rarity is not necessarily a result of it occurring less frequently. Instead, it is because explosive volcanism leaves behind thinner layers of material, so it is more easily eroded by wind and other geological activity, or hidden beneath sand and dust. In other words, the only reason we can see this new deposit at all is because it’s so young – it hasn’t yet vanished from the geological record.
When the observations from orbit are combined with the seismic data from InSight, they offer the tantalizing possibility that the Cerberus Fossae region could still see future eruptions, and that magmatic activity is still ongoing just beneath the surface there.
One speculative, but not altogether unreasonable hypothesis, suggests that this ongoing underground magma flow might have melted ice embedded in the nearby Martian subsurface, creating habitable environments for microbial life in the present day.Hydrothermal vents deep under the oceans on Earth are prime habitats for chemotropic bacteria: life that relies on inorganic molecules like iron and magnesium, rather than sunlight, to create energy. The mixture of magma and ice-water beneath the surface of Mars in the Cerberus Fossae region might provide a similarly viable habitat for this kind of microbial life. Image Credit: P. Rona / OAR/National Undersea Research Program (NURP) NOAA.
The researchers believe that “these environments would be analogous to locations on Earth where volcanic activity occurs in glacial environments such as Iceland, where chemotropic [bacteria that gains energy from oxidizing inorganic molecules], cryophilic [cold-loving], and thermophilic [heat-loving] bacteria thrive.”
For now, we have no way of testing this theory, though InSight will continue to listen for further seismic activity from it’s position about 1,600km away. In the ongoing search for microbial extra-terrestrial life, however, the Cerberus Fossae may be a promising location for future missions to explore.
The researchers published their findings in Icarus. You can read more about it here:
David G. Horvath, Pranabendu Moitra, Christopher W. Hamilton, Robert A. Craddock, Jeffrey C. Andrews-Hanna. “Evidence for geologically recent explosive volcanism in Elysium Planitia, Mars.” Icarus.
Want to Colonize Mars? Aerogel Could Help
Aerogel Greenhouses for Mars: Scientists are exploring how aerogel, a translucent, Styrofoam-like material, could be used as a building material on Mars. Aerogel retains heat structures built with it could raise temperatures enough to melt water ice on the Martian surface. Credit: NASA/JPL-Caltech. Full image and caption &rsaquo
Raising crops on Mars is far easier in science fiction than it will be in real life: The Red Planet is an inhospitable world. Among other challenges, subzero temperatures mean water can persist on the surface only as ice, and the planet's atmosphere offers little protection to plants (or people) from the Sun's radiation.
Of course, NASA has plans to eventually put humans on Mars, using lessons it will learn from its Artemis lunar explorations. And those humans will need to eat. Being able to produce food on Mars would help reduce the quantity of supplies consuming valuable space and fuel on crewed missions to the Red Planet. But figuring out how &mdash and where &mdash to produce that food, while also being exceedingly careful not to contaminate Mars with Earth-borne bacteria, are some of the challenges scientists and engineers face.
In a new paper in Nature Astronomy, researchers propose that a material called aerogel might help humans one day build greenhouses and other habitats at Mars' mid-latitudes, where near-surface water ice has been identified. The study was funded by Harvard University's Faculty of Arts and Sciences.
Aerogel is a Styrofoam-like solid that is 99% air, making it extremely light. It&rsquos adept at preventing the transfer of heat as well, making it an excellent insulator in fact, it's been used for that purpose on all of NASA's Mars rovers. Moreover, aerogel is translucent, allowing visible light to pass through while blocking ultraviolet light's harmful radiation. Most aerogel is made from silica, the same material found in glass.
In an experiment conducted by lead author Robin Wordsworth of Harvard, 2-3 centimeters of silica aerogel allowed light from a lamp tuned to simulate Martian sunlight to heat the surface beneath it by up to 150 degrees Fahrenheit (65 degrees Celsius) &mdash enough to raise temperatures on the Martian surface and melt water ice.
"The study was meant as an initial test of aerogel's potential as a Martian building material," said second author Laura Kerber, a geologist at NASA's Jet Propulsion Laboratory in Pasadena, California.
Kerber participated in a 2015 NASA workshop to identify the best places on Mars to send astronauts. "The ideal place for a Martian outpost would have plentiful water and moderate temperatures," she said. "Mars is warmer around the equator, but most of the water ice is located at higher latitudes. Building with silica aerogel would allow us to artificially create warm environments where there is already water ice available."
Broadening the regions on Mars where humans could grow things also opens up new areas where they could conduct valuable scientific research, Kerber added.
The aerogel experiment was inspired by the heating process that creates so-called dark spots that dot Mars' carbon dioxide ice caps during the spring. This kind of ice is better known on Earth as dry ice. Like aerogel, carbon dioxide ice is translucent, allowing sunlight to heat the surface below. As the soil warms, carbon dioxide gas accumulates between the ice and the warm surface, eventually causing the ice to rupture. That, in turn, creates a puff of gas that tosses soil beneath the ice onto its surface.
The experiment explored a similar process with aerogel. The paper details how both a solid piece of aerogel as well as chunks of crushed aerogel can be used to heat the surface below. The researchers used varying levels of illumination produced by Martian seasons. The results suggest aerogel could even provide a heating effect in the bitter Martian winter. In the mid-latitudes, winter nighttime temperatures can be as cold as minus 130 degrees Fahrenheit (minus 90 degrees Celsius).
The next step, Wordsworth said, is taking the experiment out of the lab and into Martian analogues like Chile's Atacama Desert or Antarctica's McMurdo Dry Valleys. Like Mars, these environments reach subzero temperatures and are exceptionally dry.
"Our prediction is that aerogel shielding should provide more efficient heating as it scales in size," Wordsworth said. "That would be important to see under field conditions."
Challenges to Be Overcome
While the experiment was an encouraging proof of concept, Wordsworth acknowledged there are still significant engineering challenges to overcome. Based on a climate model produced along with the experiment, it would take lots of aerogel and at least two Mars years (or four Earth years) of warming to produce a permanent region of liquid water underneath. Although aerogel is several times lighter than air, building structures with roofs made out of the material would require shipping large quantities of it to Mars or somehow manufacturing it there.
Silica aerogel is very fragile and porous layering it within another translucent material, or combining it with flexible materials, could prevent fracturing. Doing so could increase air pressure under a structure made with an aerogel roof or shield as well, allowing liquid water to pool more easily on the surface instead of vaporizing in the thin Martian atmosphere.
But the study's authors noted that developing small habitability zones on Mars is more plausible than attempting to "terraform" the planet, as science-fiction writers have proposed doing in the past. A NASA study last year dashed the hopes of thickening the Martian atmosphere enough to create an Earth-like greenhouse effect.
"Anything that would help make long-term habitability possible is exciting to consider," Wordsworth said.