Astronomy

Where does the CO2 in Mars atmosphere come from?

Where does the CO2 in Mars atmosphere come from?


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As far as I know, Earth and Mars were relatively similar when the solar system formed. So most of the CO2 was used to form carbonic rocks (right?). I found that tectonic movements are the reason that the CO2 on Earth could be released again, which don't exist on Mars.

So how comes that the atmosphere has 95% CO2?


The early atmospheres of Venus, Earth and Mars all had a lot of CO2, Carbon and oxygen are some of the most common elements in molecular clouds, and so it is no surprise that their most common and stable compound should be common in atmospheres.

On the Earth, life happened.

The carbon in the atmosphere was fixed by autotrophs (particularly blue-green algae and the later plants) into the bodies of living things, and then into rocks formed from those bodies: Chalk, Limestone, Coal and Oil. This left an atmosphere dominated by Nitrogen, and later by the toxic waste products from those algae: oxygen.

Mars was too small to hold onto lighter gases like Nitrogen, and these escaped into space, there is just a trace of the heavier gases: CO2, but at a very low pressure.

Venus retains a dense atmosphere dominated by CO2


In addition to James K's answer, many gases exist in the disk of material that forms into planets. What's a gas as opposed to a liquid or solid also depends on temperature and pressure. The most abundant "gases" in our solar-system are hydrogen, helium, CO2, H2O, CH4, NH3, N2, O2, CO, Neon (and maybe some others I've overlooked), in something sort of close to that order. Many of these "gases" are also ices that form up the majority of comets.

During planetary formation, the ring of debris is too warm for hydrogen, Helium and Neon to be anything but a gas, though some hydrogen is bound to heavier elements and abundant in planet formation. Helium and Neon and the other Noble Gases don't bind well with other elements.

The other abundant "gases", H20, CO2, NH3, CH4, etc, can exist as ices past their respective frost lines. That's why those molecular compounds are much more common in the outer part of the solar system.

Earth and Mars formed inside the frost-line so they formed mostly out of rocky material, after which, much of the lighter elements, primarily gases and liquids, were acquired by comet impacts after formation, though some probably existed prior too formation.

During the late heavy bombardment there were many large impacts and one consequence of very large comet or meteor impacts is a rise in temperature, so, even in the early solar-system when the sun wasn't as luminous as it is now, the planets, Earth and Mars spent some of the time quite hot.

There's two primary ways a planet can lose it's atmosphere, Jeans Escape and by the solar wind.

The solar wind is made up of almost entirely charged particles, so if a planet has a magnetic field, the impact of those high speed particles is largely deflected, where as, if they impact the upper atmosphere, the planet can lose it's atmosphere like tiny billiard balls being knocked off one at a time.

While the method of those two ways a planet can lose it's atmosphere are different, it comes down to basically the same thing. When gas molecules on the outer edge of a planet's atmosphere move faster than escape velocity they are likely to escape the planet into space and because lighter gas molecules move faster than heavier ones. That's the Maxwell-Boltzmann law or Root-mean-square formula, planets are more likely to retain heavier gases.

Venus and Mars have both lose most of their lighter gases, H20, CH4, NH3 but CO2 is heavy enough to have been retained by both those planets, though it's worth pointing out that we don't know how much CO2 Mars had millions and billions of years ago. Mars may have lost much of it's CO2 over time as well. It just lost it more slowly than the lighter gases. Mars was able to retain some of it's water, however, in the form of ice.

Venus, like Mars, lost nearly all of it's gaseous water. We know that Venus used to have much more water because it's very high D to H ratio wouldn't be possible unless it had lost a significant percentage of it's water, likely 99.9% or higher.

Earth is massive enough and Earth has a strong magnetic field, so Earth is able to retain it's lighter gases like CH4, NH3 and atmospheric H20, though Earth loses Hydrogen and Helium to space. NH3 is kind of interesting because it dissolves in water quite readily, so as soon as the young Earth had oceans, those oceans were likely Ammonia/water with whatever else readily dissolved in the liquid such as Iron. The early oceans are thought to have been brown colored from the dissolved Iron. But Earth's young atmosphere was likely mostly CO2 and CH4 with most of the H20 in liquid form, (and at times, much of it was ice).

As life and photosynthesis began releasing Oxygen, Oxygen readily bonded with the CH4 and dissolved Iron in the oceans, turning the oceans blue and in time, making the Atmosphere free of CH4 and more abundant with O2. It's unclear (and perhaps unlikely?) if Mars and Venus ever underwent that Oxygenation period that Earth did. Having abundant liquid oceans and having photosynthetic life made a significant difference to Earth's atmosphere.

You mentioned plate tectonics and that plays a role too as does the chemistry that happens in the oceans and below the surface of a planet. The main reason Mars is 95% CO2 now is because it's small and it doesn't have a good magnetic field, only small localized ones. It lost most of it's atmosphere and nearly all of it's lighter gas molecules.


Where does the CO2 in Mars atmosphere come from? - Astronomy

The graphs show monthly mean carbon dioxide measured at Mauna Loa Observatory, Hawaii. The carbon dioxide data on Mauna Loa constitute the longest record of direct measurements of CO2 in the atmosphere. They were started by C. David Keeling of the Scripps Institution of Oceanography in March of 1958 at a facility of the National Oceanic and Atmospheric Administration [Keeling, 1976]. NOAA started its own CO2 measurements in May of 1974, and they have run in parallel with those made by Scripps since then [Thoning, 1989].

The last five complete years of the Mauna Loa CO2 record plus the current year are shown in the first graph. The full record of combined Scripps data and NOAA data is shown in the second graph. Every monthly mean is the average of daily means, which are in turn based on hourly averages, but only for those hours during which “background” conditions prevail (see gml.noaa.gov/ccgg/about/co2_measurements.html for more information).

The red lines and symbols represent the monthly mean values, centered on the middle of each month. The black lines and symbols represent the same, after correction for the average seasonal cycle. The latter is determined as a moving average of SEVEN adjacent seasonal cycles centered on the month to be corrected, except for the first and last THREE and one-half years of the record, where the seasonal cycle has been averaged over the first and last SEVEN years, respectively.

The vertical bars on the black lines of the first graph show the uncertainty of each monthly mean based on the observed variability of CO2 in different weather systems as they go past the top of Mauna Loa. This is manifest in the deviations of daily means from a smooth curve that follows the seasonal cycle [Thoning, 1989]. We take into account that successive daily means are not fully independent, the CO2 deviation on most days has some similarity to that of the previous day. If there is a missing month, its interpolated value is shown in blue.

The last year of data are still preliminary , pending recalibrations of reference gases and other quality control checks. Data are reported as a dry air mole fraction defined as the number of molecules of carbon dioxide divided by the number of all molecules in air, including CO 2 itself, after water vapor has been removed. The mole fraction is expressed as parts per million (ppm). Example: 0.000400 is expressed as 400 ppm.

The Mauna Loa data are being obtained at an altitude of 3400 m in the northern subtropics, and may not be the same as the globally averaged CO 2 concentration at the surface .


Trace Gas Orbiter spots unexpected gases in Martian atmosphere

A European Space Agency instrument in orbit around Mars has spotted unexpected gases in the planet’s atmosphere, which could help to explain a longstanding mystery regarding the presence of methane there.

The ExoMars Trace Gas Orbiter (TGO) recently completed a full Martian year of observations (approximately two Earth years) and has found signatures of both ozone (O3) and carbon dioxide (CO2) for the first time. The Martian atmosphere is composed predominantly of carbon dioxide which makes up 95% of the atmosphere, with less than 0.2% of oxygen. But in the particular wavelength the TGO investigates, the scientists were expecting to see methane, not carbon dioxide or ozone.

“These features are both puzzling and surprising,” lead author Kevin Olsen of the University of Oxford said in a statement. “They lie over the exact wavelength range where we expected to see the strongest signs of methane. Before this discovery, the CO2 feature was completely unknown, and this is the first time ozone on Mars has been identified in this part of the infrared wavelength range.”

Artist’s impression of the ExoMars 2016 Trace Gas Orbiter at Mars. ESA/ATG medialab

Carbon dioxide and ozone have been previously observed by instruments like Mars Express, but the TGO was able to see these gases in the infrared wavelength for the first time, allowing scientists to see deeper into the Martian atmosphere and find traces of the gases at lower altitudes than was possible before.

The TGO is searching for methane signatures to unravel a longstanding mystery about Mars: Why does methane appear in small amounts in the Martian atmosphere when measured by some instruments, but not when measured by others? This question is particularly important because methane is a gas associated with life: It can be given off by living organisms, but it can also be created by geological processes. Now, this latest data could help to explain discrepancies in previous findings.

“Discovering an unforeseen CO2 signature where we hunt for methane is significant,” said fellow lead author Alexander Trokhimovskiy of the Space Research Institute of the Russian Academy of Sciences in Moscow in the statement. “This signature could not be accounted for before, and may therefore have played a role in detections of small amounts of methane at Mars.”

And this new information adds to our overall understanding of the complex Martian atmosphere. “Ozone and CO2 are important in Mars’ atmosphere,” Trokhimovskiy said. “By not accounting for these gases properly, we run the risk of mischaracterising the phenomena or properties we see.”

The findings are published in two articles in the journal Astronomy & Astrophysics.


Sorry, Elon. There's Not Enough CO2 To Terraform Mars

Mars might not have the right ingredients to terraform into our planetary home away from home – even with the recent discovery of liquid water buried near its south pole.

Research published Monday in Nature Astronomy puts a kibosh on the idea of terraforming Mars. At the heart of the study is carbon dioxide. Carbon dioxide, a greenhouse gas, is abundant on Mars — its thin atmosphere is made of the stuff, and the white stuff we often see on the surface is dry ice, not snow. CO2 is even trapped in the rocks and soil.

That abundance has long fueled visions of a fantasy future where all that trapped carbon dioxide is released, creating a thicker atmosphere that warms the planet. SpaceX founder Elon Musk has even proposed nuking Mars to make this happen.

But in this new study, veteran Mars expert Bruce Jakosky of the University of Colorado Boulder and Christopher S. Edwards of Northern Arizona University, surveyed how much carbon dioxide is available for terraforming the Red Planet. They combined Martian CO2 observations from various missions — NASA’s MAVEN atmospheric probe, the European Space Agency’s Mars Express orbiter, as well as NASA’s Odyssey and the Mars Reconnaissance Orbiter. The results throw shade on the dreams of futurists.

Terraforming Schemes

The paper looks at two approaches that have been discussed. In the first, humans simply raise Mars’ atmospheric pressure until space colonists can walk around with a breathing apparatus instead of the full astronaut pressure suit used in spacewalks. The other scenario looks at creating an atmosphere that allows liquid water on the surface and roughly breathable air.

Either scenario needs plenty of CO2. And … there’s just not enough. The polar caps are actually quite shallow deposits of carbon dioxide, and even exhausting all of Mars’ existing CO2 resources still creates just 15 millibars of the atmospheric pressure — on Earth, roughly 1,000 millibars is considered average pressure at sea level. Even vaporizing Mars’ carbon rich sedimentary rocks, laid down when the Red Planet was watery, would only release about 12 millibars. None of the scenarios the scientists looked at could make much of a difference, even considering unlikely conditions like creating an artificial magnetic field.

Mars is a cold, nearly airless desert, and it seems likely to stay that way.

This may not affect plans for a pressurized Mars base, but it makes the idea of actually colonizing Mars a whole lot less appealing. And while some future ideas like redirecting comets could bring more gases and water to Mars, those are way, way beyond our current means.


NASA to rely on Mars programme’s silent workhorse for years to come

NASA’s Mars Reconnaissance Orbiter, aging and arthritic a decade after its launch, remains productive and is expected to be the primary pipeline for high-resolution maps of Mars for scientists and mission planners over the next decade.

Scientists who want to study Mars’ enigmatic history, tenuous water cycle and climate will continue to rely on the nearly $900 million MRO mission, and engineers charged with selecting landing sites for future Mars rovers, and eventual human expeditions, will use maps created from the orbiter’s imagery, officials said.

And the success of future landers, beginning with NASA’s InSight seismic probe next year, depend in part on MRO’s availability to relay data from the Martian surface to Earth.

“It’s taken for granted,” said Richard Zurek, MRO’s project scientist at NASA’s Jet Propulsion Laboratory. “Everyone assumes it’s going to be there.”

The mapping orbiter, which launched 12 August 2005, and reached Mars seven months later, does not get the headlines that NASA’s Curiosity and Opportunity rovers receive.

But many of MRO’s images are just as spectacular, revealing changes in Martian landscapes as the red planet goes through its seasons, Zurek said. Some of the snapshots returned by MRO’s high-resolution camera could even be considered artistic, he said.

MRO swooped into orbit around Mars in March 2006, used the Martian atmosphere to aerobrake into a near-circular operational orbit about 300 kilometres (186 miles) above the red planet, and then began an initial baseline science campaign in November 2006 scheduled to last two years.

The mission has won additional funding from NASA in two-year increments, and it is currently approved to operate through late 2016 at a budget of about $30 million per year.

But if the orbiter remains healthy, scientists expect MRO will remain at the forefront of NASA’s Mars programme well into the 2020s. It has enough fuel to keep going into the 2030s.

“Ten years after launch, MRO continues full science and relay operations,” said Kevin Gilliland, spacecraft engineer for the mission at Lockheed Martin, which built the orbiter under contract to NASA. “We’ve kept our operations efficient. We’ve been able to bring back an astonishing amount of science data — more than 250 terabits so far. Even after more than 40,000 orbits, the mission remains exciting, with new challenges such as taking close-up images of a passing comet last year and supporting next year’s InSight landing.”

The Mars Reconnaissance Orbiter launched from Cape Canaveral on Aug. 12, 2005, aboard an Atlas 5 rocket. Credit: Pat Corkery/Lockheed Martin

Zurek said the most significant technical issue aboard MRO is in one of the spacecraft’s inertial measurement units used to determine the orbiter’s motion and orientation. Zurek said a laser inside one of the unit’s gyroscopes is showing signs of aging, and ground controllers are trying to coax the sensor along by switching to an identical backup unit.

In the meantime, engineers are working on changing the orbiter’s navigation logic to rely on star trackers in case both navigation sensors go down, Zurek said.

One of the gimbals used to point MRO’s power-generating solar panels toward the sun is also sticky, a sign of age-related “arthritis” aboard the spacecraft, Zurek said.

MRO also abruptly switches to its backup “B side” computer on occasion, temporarily interrupting scientific observations for a few days each time. Zurek said the orbiter’s ground team has learned to deal with the problem, which has escaped diagnosis with a root cause.

The spacecraft’s high-resolution camera, managed by scientists at the University of Arizona and known by the acronym HiRISE, is charged with surveying Mars for candidate landing sites for future rovers.

Imagery from HiRISE was instrumental in selecting Gale Crater as the destination for NASA’s Curiosity rover, and the camera is now snapping photos of prospective landing sites for a similar rover set for launch in 2020 and Europe’s ExoMars rover scheduled for liftoff in 2018.

NASA has also tasked MRO to snap photos of regions under consideration for human landings. The first formal workshop to discuss where astronauts should first explore Mars is scheduled for October in Houston.

“We’re going to have this information as we go forward in our programme to land things on Mars,” Zurek said in an interview with Spaceflight Now. “That just speaks to the quality and the impact of what those measurements have been to engineers.”

MRO’s capable science payload, which includes the HiRISE camera, has sent back 250 terabits of data so far. That’s equivalent to four months of non-stop high-definition video, according to NASA, more than the data haul from any other robotic probe in deep space.

Every week, MRO’s cameras, ground-penetrating radar, spectrometers and atmospheric sounder return more data than all other active Mars missions combined.

“From deep space, MRO returns the most data of any mission,” Zurek told Spaceflight Now. “That’s partly because we have such high-resolution instruments that we need that, and we’re also returning relay data (from Mars landers). That’s a small fraction of the total return, but nothing is insignificant in terms of the resources needed returning data from deep space.”

MRO’s arrival at the red planet in 2006 revealed a changing Mars, Zurek said.

“A major discovery is the diversity and ubiquity of water-related environments on Mars,” he said.

“We can observe and measure the movement of sand dunes,” Zurek said. “We see landslides on the planet because we have the resolution, and we can catch them at times when they are active.”

In the spring on Mars, the orbiter watches as the wintertime dusting of ice erodes away, erupting carbon dioxide gas in the atmosphere.

MRO has also likely discovered elusive liquid water bubbling at — or just just beneath — the Martian surface and streaming down steep slopes onto sandy fans. The scarce Martian atmosphere is too thin and frigid to sustain liquid water at the surface, but if the water is salty enough, it can remain in a liquid state in the right conditions, Zurek said.

This image from MRO’s HiRISE camera captured 30 July shows flows in Mars’ vast Valles Marineris canyon system. The flows emanate from the relatively bright bedrock and flow onto sandy fans, where they are remarkably straight, following linear channels. Valles Marineris contains more of these flows than everywhere else on Mars combined, and they are always active although on changing slope aspects with season. Credit: NASA/JPL/University of Arizona Caption by Alfred McEwen

The briny water — if that’s what it is — shows up in features called recurring slope lineae, which are “these long fingers on steep slopes during some of the warmest times of the year,” Zurek said. “They grow, the extend down the slope during that warm season, and then they fade away and finally they recur again.”

“Our best explanation for that is that these are brine flows,” Zurek said. “The surface is too cold for pure water to be liquid, but if you add salts, you can depress the freezing point.”

Zurek said he thinks scientists are close to confirming the flows are made of salty water. A confirming measurement could come from MRO’s spectrometer if the orbiter can observe a flow large enough to detect with the coarser-resolution composition instrument.

The seasonal water flows suggest there may be substantial water lurking just below the Martian surface in equatorial regions more accessible to astronauts than other water ice deposits at the poles.

The orbiter has also found evidence of Martian ice ages from layers in the planet’s northern polar ice cap, and a reservoir of frozen carbon dioxide in the southern ice cap that could have locked up a large fraction of the molecules from Mars’ atmosphere when it was much thicker in ancient times.

Despite MRO’s relatively good health, NASA is planning for a replacement. No NASA orbiters are slated to launch to Mars until at least 2022, but agency managers are working on an orbiter concept for the 2020s.

The European Space Agency is in the final stages of testing its own Mars orbiter, half of the two-part ExoMars program, for launch in January. The ExoMars orbiter will measure trace gases such as methane in the Martian atmosphere and provide data relay support for landers.

Launch opportunities to Mars come about every 26 months, when the planets are lined up to make a direct journey possible. The 2020 slot is taken by the next Mars rover, a modified version of Curiosity, so 2022 is the next chance for NASA to dispatch a U.S. orbiter.

“We know that the next set of missions will be replacing infrastructure,” said Jim Green, head of NASA’s planetary science division, in a presentation to the NASA Advisory Council in July.

Besides Earth, no other planet in the solar system boasts such a comprehensive fleet of spacecraft. Mars missions from the United States, Europe and India are driving across the surface, mapping the planet, tracking weather systems and probing Martian climate change.

Infrastructure upgrades aboard the proposed 2022 orbiter will include a radio to relay data and commands between Earth and rovers on the Martian surface. The orbiter will also likely carry a high-resolution camera at least as sensitive as the HiRISE imager, which can spot features nearly as small as an LP vinyl record, to extend the mapping capability to be lost with the end of MRO’s mission.

The new orbiter mission may also host a laser communications package to rapidly beam back science data to Earth several orders of magnitude faster than possible with existing radios. Ultra-efficient solar-electric propulsion pods could also be tested on the orbiter, according to NASA managers.

NASA officials said earlier this year that initial funding for the 2022 orbiter could be included in the agency’s next budget request to Congress in early 2016.

Follow Stephen Clark on Twitter: @StephenClark1.


NASA's Perseverance Mars Rover Extracts First Oxygen From Red Planet

MOXIE Being Installed in Perseverance: Technicians at NASA&rsquos Jet Propulsion Laboratory lower the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) instrument into the belly of the Perseverance rover. Credit: NASA/JPL-Caltech. Full image and caption &rsaquo

The milestone, which the MOXIE instrument achieved by converting carbon dioxide into oxygen, points the way to future human exploration of the Red Planet.

The growing list of &ldquofirsts&rdquo for Perseverance, NASA&rsquos newest six-wheeled robot on the Martian surface, includes converting some of the Red Planet&rsquos thin, carbon dioxide-rich atmosphere into oxygen. A toaster-size, experimental instrument aboard Perseverance called the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) accomplished the task. The test took place April 20, the 60th Martian day, or sol, since the mission landed Feb. 18.

While the technology demonstration is just getting started, it could pave the way for science fiction to become science fact &ndash isolating and storing oxygen on Mars to help power rockets that could lift astronauts off the planet&rsquos surface. Such devices also might one day provide breathable air for astronauts themselves. MOXIE is an exploration technology investigation &ndash as is the Mars Environmental Dynamics Analyzer (MEDA) weather station &ndash and is sponsored by NASA&rsquos Space Technology Mission Directorate (STMD) and Human Exploration and Operations Mission Directorate.

&ldquoThis is a critical first step at converting carbon dioxide to oxygen on Mars,&rdquo said Jim Reuter, associate administrator STMD. &ldquoMOXIE has more work to do, but the results from this technology demonstration are full of promise as we move toward our goal of one day seeing humans on Mars. Oxygen isn&rsquot just the stuff we breathe. Rocket propellant depends on oxygen, and future explorers will depend on producing propellant on Mars to make the trip home.&rdquo

For rockets or astronauts, oxygen is key, said MOXIE&rsquos principal investigator, Michael Hecht of the Massachusetts Institute of Technology&rsquos Haystack Observatory.

To burn its fuel, a rocket must have more oxygen by weight. To get four astronauts off the Martian surface on a future mission would require approximately 15,000 pounds (7 metric tons) of rocket fuel and 55,000 pounds (25 metric tons) of oxygen. In contrast, astronauts living and working on Mars would require far less oxygen to breathe. &ldquoThe astronauts who spend a year on the surface will maybe use one metric ton between them,&rdquo Hecht said.

Hauling 25 metric tons of oxygen from Earth to Mars would be an arduous task. Transporting a one-ton oxygen converter &ndash a larger, more powerful descendant of MOXIE that could produce those 25 tons &ndash would be far more economical and practical.

Mars&rsquo atmosphere is 96% carbon dioxide. MOXIE works by separating oxygen atoms from carbon dioxide molecules, which are made up of one carbon atom and two oxygen atoms. A waste product, carbon monoxide, is emitted into the Martian atmosphere.

The conversion process requires high levels of heat to reach a temperature of approximately 1,470 degrees Fahrenheit (800 Celsius). To accommodate this, the MOXIE unit is made with heat-tolerant materials. These include 3D-printed nickel alloy parts, which heat and cool the gases flowing through it, and a lightweight aerogel that helps hold in the heat. A thin gold coating on the outside of MOXIE reflects infrared heat, keeping it from radiating outward and potentially damaging other parts of Perseverance.

In this first operation, MOXIE&rsquos oxygen production was quite modest &ndash about 5 grams, equivalent to about 10 minutes&rsquo worth of breathable oxygen for an astronaut. MOXIE is designed to generate up to 10 grams of oxygen per hour.

This technology demonstration was designed to ensure the instrument survived the launch from Earth, a nearly seven-month journey through deep space, and touchdown with Perseverance on Feb. 18. MOXIE is expected to extract oxygen at least nine more times over the course of a Martian year (nearly two years on Earth).

These oxygen-production runs will come in three phases. The first phase will check out and characterize the instrument&rsquos function, while the second phase will run the instrument in varying atmospheric conditions, such as different times of day and seasons. In the third phase, Hecht said, &ldquowe&rsquoll push the envelope&rdquo &ndash trying new operating modes, or introducing &ldquonew wrinkles, such as a run where we compare operations at three or more different temperatures.&rdquo

&ldquoMOXIE isn&rsquot just the first instrument to produce oxygen on another world,&rdquo said Trudy Kortes, director of technology demonstrations within STMD. It&rsquos the first technology of its kind that will help future missions &ldquolive off the land,&rdquo using elements of another world&rsquos environment, also known as in-situ resource utilization.

&ldquoIt&rsquos taking regolith, the substance you find on the ground, and putting it through a processing plant, making it into a large structure, or taking carbon dioxide &ndash the bulk of the atmosphere &ndash and converting it into oxygen,&rdquo she said. &ldquoThis process allows us to convert these abundant materials into useable things: propellant, breathable air, or, combined with hydrogen, water.&rdquo

More About Perseverance

A key objective of Perseverance&rsquos mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet&rsquos geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust).

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA&rsquos Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

NASA&rsquos Jet Propulsion Laboratory in Southern California, which is managed for NASA by Caltech in Pasadena, California, built and manages operations of the Perseverance rover.


Can other gases help explain Mars methane mystery?

Artist’s illustration of the joint European-Russian Trace Gas Orbiter (TGO), which has been orbiting Mars since 2016. Image via ESA/ ATG medialab/ Space.com.

Is the methane in Mars’ atmosphere geological in origin, arising from processes in the Martian rocks? Or could it be a sign of life? Mars methane has been detected by telescopes on Earth, orbiting spacecraft and even the Curiosity rover on Mars. Meanwhile, European Space Agency (ESA) scientists have been frustrated by the lack of detection of methane by their Trace Gas Orbiter (TGO) – part of the ExoMars mission – designed in part specifically to measure methane. The orbiter has been circling Mars since 2016, but, so far, no methane. Now scientists think they have an answer.

The new findings come from scientists in the U.K. and Russia. They might help to explain why TGO hasn’t detected methane on Mars, ESA has reported. The answer has to do with two other gases in the atmosphere, carbon dioxide (CO2) and ozone (O3).

Researchers published two new peer-reviewed papers on July 27, 2020, in Astronomy & Astrophysics. One deals with the carbon dioxide detection and the other with the ozone.

While TGO still hasn’t directly detected methane, it did make another intriguing discovery that might explain why. It detected both carbon dioxide and ozone in the regions where methane had been expected to be seen. Both gases have been known about for a long time, and Mars’ atmosphere is mostly carbon dioxide, so why is this surprising?

Spectral signatures of carbon dioxide (left) and ozone (right) on Mars, as detected by the ACS instrument on the Trace Gas Orbiter (TGO). Image via Olsen et al./ ESA.

Kevin Olsen of the University of Oxford, who led the U.K. study, explained in a statement:

These features are both puzzling and surprising.

They lie over the exact wavelength range where we expected to see the strongest signs of methane. Before this discovery, the CO2 feature was completely unknown, and this is the first time ozone on Mars has been identified in this part of the infrared wavelength range.

TGO made the observations after studying the Martian atmosphere for a full Martian year, using its Atmospheric Chemistry Suite (ACS). ACS is extremely sensitive, and can show scientists how these gases interact with light. The researchers were not expecting to see ozone in the part of the infrared wavelength range where methane was expected to be seen. Previous observations relied upon seeing the ozone signature in the ultraviolet, a technique which only allowed measurement at high altitudes (over 20 km [12 miles] above the surface). ACS, however, can map ozone down at lower altitudes as well. From the ozone paper:

We report the first observation of the spectral features of Martian ozone (O3) in the mid-infrared range using the Atmospheric Chemistry Suite Mid-InfaRed (MIR) channel, a cross-dispersion spectrometer operating in solar occultation mode with the finest spectral resolution of any remote sensing mission to Mars.

The ability to simultaneously resolve these species has an impact on current and past attempts to measure the abundance of methane in the atmosphere of Mars.

In this region and time period, corresponding to the northern autumn equinox, we were able to observe significant amounts of ozone in the mid-infrared at altitudes below 30 km [19 miles].

Ozone absorption below 30 km in the mid-infrared range has important implications for searches for atmospheric methane. Past observations of methane in the atmosphere of Mars (Formisano et al. 2004 Krasnopolsky et al. 2004 Mumma et al. 2009 Webster et al. 2015) were a driving cause of the development of the ExoMars TGO mission. CH4 should have a relatively short lifetime in the atmosphere of Mars (several hundred years), meaning current observations require an active source (Lefèvre & Forget 2009). A key objective of the TGO mission is to determine with certainty whether or not CH4 is present in the atmosphere of Mars and what its spatial and temporal variability is, and to localize any possible sources. This story continues to be intriguing as the first results from TGO reported an upper limit on the order of 50 pptv (Korablev et al. 2019), and ACS MIR observations continue to reveal no methane after one MY. In its place, we have instead found the rare and previously undetected signatures of O3 and a new CO2 magnetic dipole band (Trokhimovskiy et al. 2020).

Another graph highlighting the unexpected carbon dioxide signature – a magnetic dipole absorption band of the molecule – as detected by the ACS instrument on the Trace Gas Orbiter (TGO). Image via Trokhimovskiy et al./ ESA.

ACS also saw carbon dioxide at the infrared wavelength range where they expected to see methane, which was also unexpected. Alexander Trokhimovsky of the Space Research Institute of the Russian Academy of Sciences in Moscow, who led the Russian study, said:

Discovering an unforeseen CO2 signature where we hunt for methane is significant. This signature could not be accounted for before, and may therefore have played a role in detections of small amounts of methane at Mars.

As noted by Meghan Bartels in an article for Space.com, the odd alignment of these two gases where methane had been expected suggests that they are interfering with the detection of methane by TGO. From the ozone paper:

The observed spectral signature of ozone at 3000–3060 cm -1 directly overlaps with the spectral range of the methane (CH4) v3 vibration-rotation band, and it, along with a newly discovered CO2 band in the same region, may interfere with measurements of methane abundance.

Comparison of the atmospheres of Mars and Earth. Image via ESA. A history of key methane measurements on Mars from 1999 to 2018. Image via ESA.

These findings do not directly disagree with those of other missions, since the observations were mostly done at different times from those that did find methane, and TGO is designed to sniff out very tiny amounts of methane, not larger plumes as seen before (although even those plumes are very small compared to methane plumes on Earth). Olsen said:

In fact, we’re actively working on coordinating measurements with other missions. Rather than disputing any previous claims, this finding is a motivator for all teams to look closer the more we know, the more deeply and accurately we can explore Mars’ atmosphere.

The researchers wondered if previous observations from Earth, Mars Express (using the Planetary Fourier Spectrometer, or PFS) or Curiosity (using the Tunable Laser Spectrometer, or TLS), could have mistaken carbon dioxide and/or ozone for some of the methane measurements, but that is considered to be unlikely. From the ozone paper:

CO2 and O3 alone cannot account for the detections made by both teams. In the case of PFS, the previously unknown CO2 features would impact all observations equally, as CO2 is always present and well-mixed. The PFS team has instead identified CH4 in only a small number of observations (Formisano et al. 2004 Giuranna et al. 2019). Furthermore, we computed spectra with O3 at two and three times the quantities in our observations, and the sheer magnitude of CH4 observed by these latter authors (15 ppbv) is far too large to be easily mistaken for O3.

In the case of TLS, which takes measurements of CH4 at the surface and mostly at night where and when the O3 abundance is greatest, again, it is unlikely that the large quantity of CH4 observed (up to 9 ppbv) resulted from O3, yet the latter may interfere in the measurement of the background level of methane in the so-called enriched mode as both ozone and methane should sustain the same enrichment.

For ground-based observations, strong O3 absorption features from Earth’s atmosphere must first be removed before retrieving mixing ratios for Mars (Krasnopolsky 2012 Mumma et al. 2009) O3 must be accounted for, although this step makes the retrieval more difficult (Zahnle et al. 2011). Finally, in the case of all previous observations, the rapid evolution and disappearance of CH4 are still not explained, although ozone chemistry is very rapid, with a lifetime on the order of days.

The possible methods by which scientists think methane can be created and destroyed on Mars. Image via ESA.

The results will not only help scientists to better track down methane, but also learn more about the Martian atmosphere overall. Alexander said:

These findings enable us to build a fuller understanding of our planetary neighbor.

Ozone and CO2 are important in Mars’ atmosphere. By not accounting for these gases properly, we run the risk of mischaracterizing the phenomena or properties we see.

Together, these two studies take a significant step toward revealing the true characteristics of Mars: toward a new level of accuracy and understanding.

TGO’s primary mission is to detect trace gases that could originate from either geological or biological processes. The ExoMars mission overall is a joint effort between Europe and Russia. According to TGO Project Scientist Håkan Svedhem:

These findings are the direct result of hugely successful and ongoing collaboration between European and Russian scientists as part of ExoMars.

They set new standards for future spectral observations, and will help us to paint a more complete picture of Mars’ atmospheric properties – including where and when there may be methane to be found, which remains a key question in Mars exploration.

Additionally, these findings will prompt a thorough analysis of all the relevant data we’ve collected to date – and the prospect of new discovery in this way is, as always, very exciting. Each piece of information revealed by the ExoMars Trace Gas Orbiter marks progress towards a more accurate understanding of Mars, and puts us one step closer to unravelling the planet’s lingering mysteries.

Kevin Olsen of the University of Oxford in the UK, who led the Mars ozone study. Image via University of Oxford.

We still don’t know the origin of Martian methane, but the new studies from Europe and Russia of other gases in the atmosphere will help to refine and narrow down the possibilities.

Bottom line: ESA’s TGO orbiter has unexpectedly detected carbon dioxide and ozone in Mars’ atmosphere where the elusive methane should be.


NASA's Perseverance rover just made breathable air on Mars

The Perseverance rover converted carbon dioxide into oxygen on Mars, marking the first time breathable air has been made on another planet, NASA announced Wednesday.

A toaster-sized instrument called MOXIE &ndash short for Mars Oxygen In-Situ Resource Utilization Experiment &ndash made the feat possible. Since Mars' atmosphere is 96% carbon dioxide, MOXIE works by separating oxygen atoms from carbon dioxide molecules.

"This is a critical first step at converting carbon dioxide to oxygen on Mars," said Jim Reuter, associate administrator for NASA's Space Technology Mission Directorate. "MOXIE has more work to do, but the results from this technology demonstration are full of promise as we move toward our goal of one day seeing humans on Mars."

In its first test on the Red Planet, MOXIE produced about 5 grams of oxygen, the equivalent of 10 minutes' worth of breathable oxygen for an astronaut. MOXIE can generate up to 10 grams of oxygen per hour. MOXIE is expected to extract oxygen at least nine more times over the course of a Martian year &ndash nearly two years on Earth.

The Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) instrument converts carbon dioxide into oxygen. NASA/JPL-Caltech

There's another reason oxygen on another planet is vital: Rockets use oxygen to burn fuel and must have more oxygen than they weigh, according to NASA.

Trudy Kortes, director of technology demonstrations within the mission directorate, said in a statement that MOXIE isn't just the first instrument to produce oxygen in another world, it will help future missions "live off the land" while using elements of another world's environment.

Space & Astronomy

"It's taking regolith, the substance you find on the ground, and putting it through a processing plant, making it into a large structure, or taking carbon dioxide &mdash the bulk of the atmosphere &mdash and converting it into oxygen," Kortes said. "This process allows us to convert these abundant materials into useable things: propellant, breathable air, or, combined with hydrogen, water."

It's been an eventful week on Mars. NASA's $80 million Ingenuity helicopter spun up its carbon-composite rotors and lifted off on Mars on Monday to become the first aircraft to fly on another planet, a "Wright brothers moment" that could pave the way to future interplanetary aircraft.

First published on April 22, 2021 / 12:29 PM

© 2021 CBS Interactive Inc. All Rights Reserved.

Christopher Brito is a social media producer and trending writer for CBS News, focusing on sports and stories that involve issues of race and culture.


Oxygen on Mars Is Behaving in a Way Scientists Can't Explain

Atmospheric gases on Mars sure provide us with plenty of mystery. First, there was that business with the disappearing, reappearing methane. Now, oxygen levels have been observed rising and falling over the Gale Crater, by amounts that just don't fit any known chemical processes.

The data comes from Curiosity, the Mars rover that's been making its slow and methodical trek across the crater floor and up the foot of Mount Sharp in the centre of it.

The robot isn't just looking down at the rocks beneath its treads Curiosity also takes readings of the Martian atmosphere to measure the seasonal atmospheric changes. It's been up there for three Mars years now (that's six Earth years), and scientists poring over the measurements have noticed that oxygen in the planet's atmosphere isn't behaving entirely as expected.

There actually isn't all that much oxygen on Mars. Most of its thin atmosphere (95 percent by volume) is carbon dioxide, or CO2. The rest is made up of 2.6 percent molecular nitrogen (N2), 1.9 percent argon (Ar), 0.16 percent molecular oxygen (O2), and 0.06 percent carbon monoxide (CO).

(Earth's atmosphere, by contrast, is mostly nitrogen, at 78.09 percent by volume, and 20.95 percent oxygen.)

On Mars, atmospheric pressure changes over the course of the year. On the winter hemisphere, CO2 freezes over the pole, which causes the pressure to drop across the hemisphere. This results in a hemisphere-to-hemisphere redistribution of gases to equalise atmospheric pressure planet-wide.

In spring, when the polar caps melt and release the CO2, the opposite effect occurs: pressure initially rises in that hemisphere, then evens out as gases are redistributed towards the winter hemisphere.

So, the fluctuations of the other gases are predictable in proportion to the CO2 levels. Or at least, they should be. In the case of nitrogen and argon, it is - these gases have been behaving more or less exactly as expected. But oxygen? Nope.

During spring and summer, oxygen rose by around 30 percent, dropping back to normal levels in autumn. This happened every year, but since the amount by which the oxygen rises varies from year to year, it seems like something is adding the oxygen, and then taking it away again.

There is no known process that can produce this result.

The obvious question for such an odd measurement was whether there could be something wrong with the Quadrupole Mass Spectrometer instrument or software. Several checks saw that it was all working fine.

Another possibility was whether the oxygen could be produced by water or carbon dioxide somehow breaking apart in the atmosphere. This was quickly ruled out too - there's not nearly enough water in the Martian atmosphere, and CO2 breaks down too slowly to fit the observed fluctuations.

Now, Martian soil does contain a lot of oxygen. But the conditions required to release it have not been observed - and that wouldn't explain where it disappears to each year. The process whereby solar radiation breaks apart oxygen and it dissipates into space is likewise too slow.

"We're struggling to explain this," said planetary scientist Melissa Trainer of NASA's Goddard Space Flight Center.

"The fact that the oxygen behaviour isn't perfectly repeatable every season makes us think that it's not an issue that has to do with atmospheric dynamics. It has to be some chemical source and sink that we can't yet account for."

But there is one clue. The methane. It, too, rises dramatically over Mars' summer months, increasing by up to 60 percent. Sometimes the methane and oxygen levels even seem to rise in tandem. It's possible that whatever it is that causes the methane fluctuations is also causing the oxygen fluctuations.

What that could be is still a huge question. Both gases can be produced through organic processes - that is, life - and both can be produced through geological processes.

We don't, as yet, have any evidence that there is life on Mars, but nor can it be ruled out as a cause. (Mars 2020 is going to look for fossils, so maybe we'll find out soon.)

However, the team believes it is much more likely to be geological.

"We have not been able to come up with one process yet that produces the amount of oxygen we need," said astronomer Tim McConnochie of the University of Maryland.

"But we think it has to be something in the surface soil that changes seasonally because there aren't enough available oxygen atoms in the atmosphere to create the behaviour we see."


No Seriously, Elon. You Can’t Just Nuke Mars (We Asked)

On Monday, a study published in Nature Astronomy took an exhaustive look at what it would take to terraform the Red Planet and fulfill generations of sci-fi dreams.

In it, leading Mars experts tallied the planet’s stores of carbon dioxide, a powerful greenhouse gas, and gauged the likelihood of releasing all that CO2 to create a stable atmosphere — one thick enough to have liquid water on the surface.

Their disappointing conclusion: You can’t terraform the place with any present or near future technology.

But not everyone is buying it.

SpaceX founder Elon Musk tweeted at Discover that there is a “massive amount of CO2 on Mars adsorbed into soil that’d be released upon heating. With enough energy via artificial or natural (sun) fusion, you can terraform almost any large rocky body.”

Musk is referring to carbon dioxide molecules that have stuck to the planet’s rocks over time. In the past, he’s proposed nuking the Red Planet to release these buried gases. Here, he could also be referring to using fusion as a power source that could heat Martian rocks.

So, we went back to the scientists to see what’s possible.

The astronomers said such a transformation would require technologies that aren’t here — or even anywhere near here — yet. And if we want to colonize Mars in the next few decades, we need to think in terms of what we’ll have in the next few decades. And that isn’t fusion.

“When you’re thinking about a technology far into the future, you can think about anything you like and imagine it’s feasible,” says Bruce Jakosky, head of NASA’s Mars MAVEN mission and lead author of the Nature Astronomy paper.

“That’s why we stuck with today’s technology — things we actually know how to do,” he adds.

Can’t We Though?

However, Jakosky says Elon’s not wrong in one sense: There is adsorbed carbon dioxide on the planet, as the team mentioned in their paper. But put simply, extracting it is a hard, hard process.

“On a global scale, I can only think of two possibilities,” Jakosky says of extracting the adsorbed CO2.

One of those would require producing massive amounts of greenhouse gasses on Mars’ surface. Essentially, this method would involve importing or manufacturing CFCs — usually known as ozone killing gases on Earth — and releasing the pollutants into the air to drive climate change.

The other method Jakosky suggests would mean building a mirror as large as the Red Planet’s dayside that could rapidly heat the entire globe, hopefully releasing little bits of CO2 everywhere. That’s because any localized process (like a fusion power plant) just can’t release enough carbon dioxide from the rock to make a difference.

Both of those ideas are centuries away from being even remotely possible.

And even if you did find an efficient process to extract adsorbed CO2 out of the rock — and you discovered an optimistic amount of CO2 inside all those rocks — you still wouldn’t release enough to greenhouse gases to give Mars a comparable air pressure to Earth at sea level, a unit of measurement known as a bar.

“You would still fall well short of a bar,” Jakosky says. “But you would get some significant warming and significant pressure.”

His co-author, Christopher Edwards of Northern Arizona University, says this is partly because the process of adsorption of CO2 into Martian rock isn’t as efficient as it is on Earth.

On Earth, we have carbon sinks like limestone, which store up lots of adsorbed CO2. But these are gently guided along by microbe colonies and warm temperatures. So far, the trapped carbon seen on Mars has seeped in through non-living, cold processes. And it’s spread out fairly evenly across the planet without a (known) large subsurface deposit.

“It’s really difficult to find any source of material that’s significant that can really augment the Martian atmosphere,” Edwards says.

Digging Deep

Roger Wiens, a scientist at Los Alamos National Laboratory, leads the team behind ChemCam, an instrument aboard NASA’s Curiosity rover. This instrument fires laser pulses at Martian rocks and analyzes the chemical composition of what comes out. He says that Curiosity has seen few carbonate bearing rocks at Gale Crater — the sort of calling card of adsorbed CO2.

“Carbonates are generally not that abundant on Mars,” Wiens says. “When you think about sediments on Earth, you think about carbonates because they’re everywhere.”

This is partly because Mars doesn’t have effective ways to sequester them over time.

Earth has lots of things going for it that Mars doesn’t — a magnetic field and a larger radius to help hold onto its atmosphere better. It also has plate tectonics to grab limestone, plus other carbonates to pull those down into the interior. That’s why Wiens doesn’t think we should expect to find any great reservoir of CO2 on the surface. Subduction events to bury carbon dioxide, like those seen on Earth, were likely rare and shallow on Mars.

There is one exception: There’s likely carbon from the very, very early days of Mars trapped deep, deep below the surface.

But “that’s just material that just comes out by volcanism, that’s not something that humans have access to in terms of terraforming,” Wiens says.

And while there are a few carbonate heavy areas, they seem to be localized.

Some have been seen from orbit, but only one has ever been explored by rover. The Spirit rover explored Gustav Crater from 2004 to 2010 and found a decent amount of carbonate bearing formations there.

“In these formations, they’re the dominate mineral, but these formations are relatively limited in size,” Wiens says. The Mars 2020 rover, set to launch in a year, is set to explore areas believed to have more carbonate bearing rock, probably formed in Mars’ much wetter past.

But unless Mars 2020 has an explosive revelation to share with us, terraforming proponents likely won’t catch a break.

So, for now, we might be able to explore Mars, and even set up a base in the near future. But we shouldn’t expect nuking the Red Planet to do much other than make a mess. No matter how hard you work the soil, you can’t make a lot of carbon dioxide out of only a little trapped there.



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