ESA ExoMars Landing Sites: Four Candidates selected

Four possible landing sites are being considered for the ExoMars 2018 mission. 

The sites; Mawrth Vallis, Oxia Planum, Hypanis Vallis and Aram Dorsum, are indicated in this context map. 

All four are close to the Martian equator.

The search for a suitable landing site for the ExoMars Rover began in December 2013, when the science community was asked to propose candidate sites.

Eight proposals were received and carefully considered during a scientific workshop in March of this year.

By the end of that workshop, there were four clear front-runners. Following additional review by the Landing Site Selection Working Group, the four sites have now been formally recommended for further detailed analysis.

ExoMars is a joint two-mission endeavour between ESA and Russia’s Roscosmos space agency.

The Trace Gas Orbiter and an entry, descent and landing demonstrator module, Schiaparelli, will be launched in January 2016, arriving at Mars nine months later.

The Rover and Surface Platform will depart in May 2018, with touchdown on Mars in January 2019.

Mawrth Vallis is one of four candidate landing sites under consideration for the ExoMars 2018 mission. 

It is one of the oldest outflow channels on Mars, at least 3.8 billion years old.

It hosts large exposures of finely layered clay-rich rocks, indicating that water once played a role here.

The image combines HRSC images from ESA Mars Express with MOLA topography data from NASA’s Mars Global Surveyor.

The landing ellipses under evaluation for this site selection are indicated, and cover an area of 170 x 19 km.

The orientation of the landing ellipse depends on when the launch takes place within a given launch window, the sites have to be compliant with launch opportunities in both 2018 and 2020, as indicated.

NASA MRO: Lava, not water, formed canyons on Mars

The Grand Canyon of Mars – Valles Marineris. Credit: NASA,Viking Project,USGS, CC BY

The canyon-like scars which line Mars' crust are seen by many as evidence for liquid water but a study now suggests that a different kind of fluid, one much less hospitable to life, may actually have carved these features.

On Mars, the most striking topography occurs around the equator. The planet's low latitudes are dominated by the Tharsis plateau, which hosts several towering volcanoes.


Not far off sits the solar system's largest, Olympus Mons. Near the Eastern fringe, however, things start to get deep.

There the land dives into a winding maze of valleys and river-like "outflow channels", the former including the 4000km-long Valles Marineris, the "Grand Canyon" of Mars, which exceeds its terrestrial namesake in every dimension.

These great gouges are widely thought to have been formed, at least in part, by flowing water. But according to recently published research, they could have had a very different genesis, linked to the volcanoes to the West.

Explosive erosion
A paper by Giovanni Leone of the Swiss Federal Institute of Technology, published in the Journal of Volcanology and Geothermal Research, suggests that the martian valleys and outflow channels were in fact formed mostly by lava flows, which erupted from the Tharsis plateau in the planet's distant past.

To draw this conclusion, Leone scrutinised thousands of images from NASA's Mars Reconnaissance Orbiter (MRO) spacecraft, which has been orbiting the planet since 2006.

This allowed him to map the floors of the equatorial valleys and outflow channels at an extremely high resolution of up to 25cm per pixel.

These images appear to show extensive lava flows draping the floors of many of the valleys and channels. Around 90% of the floors look to be covered either by lava or by lava-related landslides.

Valles Marineris 

Credit: G. Neukum/ESA/Mars Express/DLR, CC BY

The morphology of the lava flows Leone encountered suggest that the lava actually incised the valleys and channels in the first place.

The MRO images seem to show that channels formed by the freshly erupted lava were later deepened and widened by the passage of liquid rock.

This type of erosion, Leone argues, can explain the existence of the valleys and outflow channels without the need to invoke significant amounts of liquid water.

The valleys and outflow channels are believed to be many billion years old. Leone believes the lava would have been emitted by now-vanished volcanoes somewhere on the Tharsis plateau, forerunners of the region's (relatively juvenile) modern volcanoes.

Leone believes that every stage of this volcanic erosion process is visible in the MRO images. The first stage, he concludes, can be seen in the locations closest to today's Tharsis volcanoes, at the western end of Valles Marineris. Here lava tunnels seem to have collapsed, forming "pit chains" – long curvilinear depressions in the crust.

Further east, where the terrain deepens, the pit chains seem to have been further eroded, by the injection of yet more lava, into more extensive channels – first into "fossae" and later into larger "chasmata".

The MRO images showed relatively little evidence for the past presence of liquid water in the valleys and outflow channels, which can be inferred by the presence of "light toned deposits" in the images. This, Leone believes, adds further weight to the theory that these features are igneous in origin.

ESA ExoMars could detect bacteria on Mars past and present

An artist’s conception of the European Space Agency’s ExoMars rover, scheduled to launch in 2018. Credit: ESA

Signs of life on the Martian surface would still be visible even after bacteria were zapped with a potentially fatal dose of radiation, according to new research—if life ever existed there, of course.

Using "model" bacteria expected to resemble what microbes could look like on the Red Planet, the research team used a Raman spectrometer—an instrument type that the ExoMars rover will carry in 2018—to see how the signal from the bacteria change as they get exposed to more and more radiation.

The bottom line is the study authors believe the European Space Agency rover's instrument would be capable of seeing bacteria on Mars—from the past or the present—if the bacteria were there in the first place.

Readings from the NASA Mars Curiosity rover recently found that humans on the surface of Mars would have a higher risk of cancer due to the increased radiation level on the surface.

Mars does not have a global magnetic field to deflect radiation from solar flares, nor a thick atmosphere to shelter the surface.

The new study still found the signature of life in these model microbes at 15,000 Gray of radiation, which is thousands of times higher than the radiation dose that would kill a human. At 10 times more, or 150,000 Gray, the signature is erased.

"What we've been able to show is how the tell-tale signature of life is erased as the energetic radiation smashes up the cells' molecules," stated Lewis Dartnell, an astrobiology researcher at the University of Leicester who led the study.

ExoMars 2016 Mission to the Red Planet. 

It consists of two spacecraft – the Trace Gas Orbiter (TGO) and the Entry, Descent and Landing Demonstrator Module (EDM) which will land. 

Credit: ESA

Specifically, the spectrometer detected carotenoid molecules, which can be used to protect a microorganism against difficult conditions in the environment.

The research teams stated that these cartenoids have been proposed as "good biosignatures of life" on Mars.

"In this study we've used a bacterium with unrivaled resistance to radiation as a model for the type of bacteria we might find signs of on Mars."

"What we want to explore now is how other signs of life might be distorted or degraded by irradiation," Dartnell added.

"This is crucial work for understanding what signs to look for to detect remnants of ancient life on Mars that has been exposed to the bombardment of cosmic radiation for very long periods of time."

ESA's ExoMars: Neptec wins contract to develop cameras

The main challenge in the development of these cameras will be to design them to withstand the extreme environmental conditions that will be experienced on the surface of Mars.

Neptec Design Group has signed a contract with EADS Astrium UK Limited for the design and build of navigation cameras for the ExoMars Rover.

The ExoMars Programme has the goals of understanding the Martian environments and establishing whether life had or could now exist on Mars.

The Programme comprises two Missions: an Orbiter in 2016; and a Rover Mission in 2018.

Contracts with European organisations represent an increasing portion of Neptec's Space Exploration business as the company expands beyond its core business with the NASA and the Canadian Space Agency (CSA).

"We are thrilled to be a part of this exciting journey in exploring the planet Mars," said Mike Kearns, Neptec President of Space Exploration.

"The vision cameras that we are developing will be the eyes of the rover as it explores the surface of Mars." The main challenge in the development of these cameras will be to design them to withstand the extreme environmental conditions that will be experienced on the surface of Mars.

"This ExoMars programme is an example of what can be accomplished when governments and industry work together in the space sector," said Neptec's CEO Iain Christie.

"The contract for these navigation cameras has involved the co-operation of the Canadian Space Agency, and the European Space Agency."

The ExoMars Programme is a European Space Agency Robotic Exploration Mission under the prime contractorship of Thales Alenia Space Italia, with EADS Astrium UK Limited leading the Rover Vehicle developments.

ESA EXOMARS: Tests self-steering Rover in Chile's ‘Mars’ desert

ESA assembled a top engineering team, then challenged them to devise a way for rovers to navigate on alien planets.

Six months later, a fully autonomous vehicle was charting its course through Chile’s Mars-like Atacama Desert.

May’s full-scale rover field test marked the final stage of a StarTiger project code-named ‘Seeker’.

Standing for ‘Space Technology Advancements by Resourceful, Targeted and Innovative Groups of Experts and Researchers’, StarTiger involves a multidisciplinary team gathered at a single site, working against the clock to achieve a technology breakthrough.

 “Our expert team met at the Rutherford Appleton Laboratory in the UK,” explained Gianfranco Visentin, head of ESA’s Automation and Robotics section.

“Their challenge was to demonstrate how a planetary rover – equipped with state-of-the-art autonomous navigation and decision-making software – could traverse 6 km of Mars-like environment and come back where it started.”

Mars rovers cannot be remotely ‘driven’. It takes radio signals up to 40 minutes to make a round trip between Mars and Earth. Instead, rovers are given instructions to carry out autonomously.

“ESA’s ExoMars rover, due to land on Mars in 2018, will have state-of-the-art autonomy,” added Gianfranco.

“However, it will not travel more than 150 m per individual ‘Sol’ – a martian day – or much more than 3 km throughout its mission.

NASA Mars Exploration: Seeking Public Opinion!

NASA is giving you a platform in the form of the NASA Mars Forum that is currently calling for participants. Throughout June you can pose questions related to the re-planning of the Mars Exploration Program.

With the reduced 2013 US budget for space exploration, NASA was forced to withdraw from two missions planned together with the European Space Agency (ESA).

Further revision of the Mars Exploration Program (MEP) is also needed to accommodate new developments in science, human space flight, and technology.

Last week, a Mars exploration workshop was held in Houston, Texas with all the outputs now available at the Mars Exploration Concepts and Approaches website.

Various challenges, approaches, and strategies are presented here for the website visitors to get inspired and contribute to the forum with their opinions and ideas.


The activity should result in selecting the highest pay-off mission architecture with the first launch opportunity in 2018. The strategy will take into account the challenge of sending humans to orbit Mars in the 2030s.

The experimental forum will be active until July 1, 2012. NASA hopes the forum will provide them with a better understanding of public interest and specific areas on which to focus attention.

Russia agrees deal with Europe to save ExoMars

Russia's space agency Roscosmos has confirmed it is willing to help Europe explore Mars, putting the ExoMars project back on track after NASA pulled out.

Head of Roscosmos Vladimir Popovkin met Jean-Jacques Dordain, Director General of the European Space Agency (ESA) on Friday to discuss combining forces.

The two men signed a memorandum of understanding which will be followed by a formal agreement in November after further discussions on funding the missions.

Popovkin’s spokeswoman Anna Vedishcheva said: "The sides consider this project feasible and promising. They are to sign the deal by year-end."

Participation by the eastern power was also approved last week by the space council of the Russian Academy of Sciences.

Their agreement comes after preliminary talks at an Ariane 5 launch at Kourou, French Guiana last month. It follows NASA's decision to pull out as a partner in February as a result of swingeing cuts to the US space budget. This removed $2 billion of funding from the joint project.

Two missions are planned under the ExoMars banner. ESA is due to take the lead in 2016 with an orbiting satellite that will study methane and trace gases in the martian atmosphere, and an Entry, Descent and Landing Demonstrator Module (EDM) that would hopefully become Europe's first craft to touch down successfully on Mars.

Two years later, NASA was to have taken charge with a mission that would carry two rovers, one from the US and the other from ESA, to land at the same spot on Mars. Astrium's UK division has been carrying extensive tests developing prototypes for Europe's rover.

As well as a stereoscopic camera acting as the rover's eyes, the rover's experiments will include Life Marker Chip, developed by Professor Mark Sims at the UK's University of Leicester, that has been compared to a pregnancy test. It will study samples of Martian soil drilled from beneath the surface for molecules associated with life, such as amino acids.

Russia had already been indicating late last year that it would like to get involved with ExoMars before it suffered the disastrous loss of its own probe Phobos-Grunt which was meant to bring back a sample of a martian moon but which failed to escape Earth orbit.

Now it wants to fill the void left by NASA and to supply Proton rockets to launch the ExoMars missions plus other equipment in return for sharing the scientific data gained from them.

ESA has allocated a one billion euro budget for its share of spending on ExoMars. Funds for Russia's contribution are expected to come partly from insurance payouts for the loss of Phobos-Grunt.

A NASA rover, Mars Science Laboratory, or Curiosity, is currently en route to Mars and is due to land on August 6.

ExoMars Mission in Danger: ESA Lose NASA Partnership

NASA may be compelled to bow out of the European Space Agency-led ExoMars missions, which aim to launch an orbiter and a rover to the Red Planet, if the budget for the next fiscal year forces deep cuts to its planetary science programs.

Experts say that if reports that President Barack Obama's budget request will allocate $1.2 billion to the program, compared with the $1.5 billion that planetary science received in fiscal year 2012 are true, the program will suffer serious cuts.

The 20 percent cut would make it tougher for the space agency to tackle ambitious exploration projects, including ExoMars.

The ExoMars mission would launch the Trace Gas Orbiter toward the Red Planet in 2016 and a robotic rover, which will carry a sizable drill that will allow it to sample subterranean soils, in 2018.

It was formally initiated in Europe in 2005 and ESA has already spent around 200 million euros on technology development.

ESA invites Russia to join ExoMars project

Europe has formally invited Russia to participate in space missions to Mars in 2016 and 2018.

A "yes" from the Russian space agency (Roscosmos) may be the only way of saving the missions which are at risk of cancellation due to lack of funds.

The 2016 mission involves a satellite to study the Martian atmosphere, while a big robot rover to investigate the surface is scheduled for 2018.

Both are being planned with the US, which is also struggling financially.

If Russia can be persuaded to provide a rocket to launch the 2016 satellite, it should make both atmospheric and surface ventures financially feasible.

But the European and US space agencies (Esa and Nasa) know that for Roscosmos to be interested, it will want a meaningful degree of participation.

The in-kind return for Russia would be the opportunity to provide instrumentation and technology for the missions, and for its researchers to be included in the science teams.
Proton rocket If Russia could bring a Proton rocket to the project, it would become financially more feasible

Esa, Nasa and Roscosmos have set themselves a deadline of January to see if there is a way all parties can be satisfied.

"Everything is open for discussion," said Esa director of science, Alvaro Gimenez.

"There are possibilities for the Russians to contribute to the rover; there may also be possibilities for them to contribute to the payload on the orbiter," he told BBC News.

"Of course, in the case of 2016, we don't have much time available to get everything on board; and in the case of 2018, we don't have much room available because it is just a single Esa/Nasa rover.

"That's why we have to start the discussions now, to see what the Russians have available and what they can develop in a fast-track."

Esa's and Nasa's joint Mars programme (known in Europe as ExoMars) has looked increasingly unsteady in recent months.

The US let it be known during the summer that it could no longer afford to provide the rocket to launch the 2016 orbiter; and Europe, which still has not raised the full funds needed for ExoMars among its member states, has no money available to buy a rocket itself.

The hope is that by bringing Roscosmos into the programme, Russia could supply one of its Proton launch vehicles to send the satellite on its way.

MARS Simulation on Tenerife mountain top

One of the most exciting parts of my astrobiology research is working out how to search for evidence of past Martian life - signs of ancient biology that may have fallen extinct hundreds of millions of years ago.

One promising technique for finding these "biosignatures" - which could be pockets of organic molecules or even microbial life - is to entice them to glow in the dark using an ultraviolet laser mounted on a robotic probe. A camera on the probe would then detect the glow.

If you've ever had a gin and tonic in a nightclub you are probably already familiar with this effect. You'll have noticed how the ultraviolet lights in the club (we see them as black) cause the G&T to emit an eerie blue glow. This is caused by quinine, an organic molecule in the tonic water, fluorescing. It is this bitter-tasting compound that gives tonic water its anti-malarial properties so it's funny to think how far we've come since Victorian colonists in East Africa supped medicinal G&T sun-downers!

I have been testing this technique in the lab but it is now time to try the equipment in a more realistic scenario. So next week I'm flying out to Tenerife in the Canary Islands to carry out fieldwork in the volcanic caldera that sits like a giant pimple on the face of this tiny island. The barren rocky terrain and volcanic geology around Tenerife are a good approximation to the Martian landscape, and, in fact, prototypes for Mars rovers are put through their paces here.

I am part of a team of scientists, lead by Derek Pullan at Leicester University, who will be field-testing different instruments and camera systems. The system I'll be testing involves a sensitive digital camera and an ultraviolet light source. Because we'll be operating by day I'll have to shield everything from the bright sunlight beneath a thick photographic blanket. My rucksack will also be laden with other snazzy kit like a laser range-finder and GPS-equipped camera to record the environment around my test sites.

There are still a few things to sort out, but I'm pretty much good to go now. Holiday snaps to follow!

ESA ExoMars: French Concerns Throw Mission Plan Into Doubt

The U.S.-European Mars exploration program featuring launches in 2016 and 2018 is facing new turbulence following the French government’s refusal to endorse new spending until the 2018 mission is better defined and given a bigger budget, according to European government and industry officials.

The French space agency, CNES, had already signaled to its fellow European Space Agency (ESA) governments in late May that it needed more time to evaluate the impact of NASA’s decision to scrap a NASA rover in 2018 in favour of a joint NASA-ESA vehicle.

Lone among ESA governments taking part in the mission, CNES voted against forwarding ESA’s ExoMars program, which includes a 2016 Mars orbiter in addition to the 2018 launch of the rover, to ESA’s check-writing body, called the Industrial Policy Committee.

CNES’s concerns were apparently insufficient to prevent ESA’s Human Spaceflight and Operations Directorate, meeting May 26-27, from approving the new ExoMars configuration despite the many unknowns about the NASA-ESA rover.

Precise information on the rover’s cost and configuration, including the work distribution between ESA and NASA, will not be settled until October 2011.

ESA’s Industrial Policy Committee, which approves the agency’s expenditures, is scheduled to meet June 29-30 to approve a resumption of full ExoMars spending following a suspension of most work in April.

The work suspension was caused by NASA’s decision, announced in March, that it could no longer afford its own rover and would seek a single U.S.-European rover for the 2018 launch.

The Industrial Policy Committee had been expected to reopen the ExoMars financial spigot given the approval of the Human Spaceflight and Operations Directorate.

Given that France is a major partner and owns some of the most experienced manufacturers of aerospace equipment (EADS, THALES, etc.), it is uncertain whether the financial approval can occur. Something that ESA and CNES will be well aware of.

ESA officials had wanted to approve continued funding of ExoMars as soon as July 1 because of what they said were tight deadlines for the industrial contracting team working on the 2016 mission.

ESA’s ExoMars prime contractor, Thales Alenia Space of France and Italy, had said it needed to begin full-scale construction on the 2016 mission, which features a Mars telecommunications relay orbiter, this summer without waiting for the end of negotiations on the 2018 rover.

Read more here

ESA & NASA ExoMars contract proposal: Mission Rover

The industrial team leading Europe’s two-part ExoMars mission with NASA will submit a contract proposal in January valued at around 550 million euros ($753 million) for approval by the European Space Agency (ESA), the program manager for prime contractor Thales Alenia Space Italy said Nov. 24.

The 18-nation ESA has already spent nearly 200 million euros on the design and early development phases for ExoMars, which is a deep collaboration with NASA on missions set for launch in 2016 and 2018.

Both will be launched by NASA-provided Atlas 5 rockets as part of the division of roles agreed to between the two agencies.

NASA and ESA officials have said the missions, whose work shares took months to sort out, could serve as a model for a future global space-exploration strategy being developed by the world’s principal spacefaring nations.

The 2016 mission, to be led by ESA, will include a Mars telecommunications orbiter that will also examine the Mars atmosphere, and in particularl take a further look at still-unexplained methane concentrations that have given some hope that it might be a sign of biological life. It could also be geological activity on the planet.

This mission will also include an entry, descent and landing system, a 600-kilogram module that will land on the martian surface in the middle of the seasonal dust storm. It is designed to operate on the surface for less than two days.

The NASA-led 2018 mission will include NASA- and ESA-provided rovers to be lowered to the surface attached by tether to NASA’s sky crane, to be first used on the U.S. space agency’s Mars Science Laboratory mission.

The Mars Science Laboratory, a small-truck-sized rover, is scheduled for launch in late 2011. ExoMars program officials say the entry, descent and landing maneuver of the two rovers will be one of the mission’s most stressful moments.

UK Space Agency Funds International Mars Rover

UK Space Agency Funds International Mars Rover

The ExoMars rover is a robotic scientist which will search for evidence of past and present life and study the local Martian environment to understand when and where conditions that could have supported the development of life may have prevailed.

The UK Space Agency is announcing Pounds 10.5M for the development of instruments to search for signs of past or present life on Mars.

The instruments are part of the scientific payload on the ExoMars rover to be launched in 2018 as part of a joint mission between the European Space Agency (ESA) and US space agency NASA. ExoMars is a flagship project in the UK Space Agency's science and exploration programme.

A two-step programme, the adventure begins in 2016 when NASA will launch an ESA-led orbiter to try to understand the origin and distribution of trace gases in the atmosphere of the Red Planet. In particular, it aims to explain why methane - a gas which scientists know should be destroyed in the atmosphere within a few hundred years - seems to be continuously forming at certain places on the planet.

The orbiter will also release an experimental probe which will make a fiery descent into the thin Martian atmosphere and use its on-board rockets to demonstrate Europe's ability to make a controlled landing on another planet.

Then in 2018, NASA will land ESA's ExoMars rover alongside a NASA rover. Thanks to funding from the UK Space Agency, the rover vehicle for ExoMars is being designed and tested by leading UK space company EADS Astrium at its facility in Stevenage, Hertfordshire under a multi-million pound contract.

The ExoMars rover is a robotic scientist which will search for evidence of past and present life and study the local Martian environment to understand when and where conditions that could have supported the development of life may have prevailed.

Unlike previous US rovers, ExoMars will carry a radar able to search beneath it for scientifically promising locations under the surface and a drill to extract samples from 2 m down that will be fed to its on-board laboratory.

The UK is leading on developing two of the nine instruments (the Life Marker Chip and the Panoramic Camera) on the rover and has a major involvement in two other instruments (the Raman Laser Spectrometer and the X-Ray diffactometer).

David Willetts, Universities and Science Minister, said, "The UK's world-leading technology will play a major role in this international ExoMars project.

Our scientists will expand our knowledge of the red planet and help generate applications for these technologies here at home to benefit society and the economy. It's exciting to see UK engineers working on the most ambitious Mars mission ever attempted."

ESA tooling up for ExoMars mission

ESA and NASA are inviting scientists from across the world to propose instruments for their joint Mars mission, the ExoMars Trace Gas Orbiter. Scheduled for launch in 2016, the spacecraft will focus on understanding the rarest constituents of the martian atmosphere, including the mysterious methane that could signal life on Mars.

Establishing whether life ever existed, or is still active on Mars today, is one of the outstanding scientific quests of our time. Both missions in the ExoMars programme will address this important goal. The first spacecraft is the Trace Gas Orbiter, which ESA will build and NASA will launch.

Today, both space agencies issued an Announcement of Opportunity inviting scientists to propose instruments to be carried on the mission. Once all proposals are in, they will be evaluated and the winning teams will be tasked with building the actual hardware.

A Joint Instrument Definition Team has identified a model payload based on current technology, but turning that blueprint into reality is now the job of the scientific community. "We are open to all instrumental proposals so long as they help us achieve our scientific objectives," says Jorge Vago, ESA ExoMars Project Scientist.

The priority for this mission is to map trace gases in the atmosphere of Mars, distinguishing individual chemical species down to concentrations of just a few parts per billion. Of these gases, one in particular attracts special attention: methane.

Discovered on Mars in 2003, it happens to be a possible 'biomarker', a gas that is readily produced by biological activity. Understanding whether the methane comes from life or from geological and volcanic processes takes precedence. "The methane is the anchor point around which the science is to be constructed," says Vago.

Adding to the mystery is that methane was found to be concentrated in just three locations on Mars, and then disappeared much faster from the atmosphere than scientists were expecting. This points to an unknown destruction mechanism much more powerful than any known on Earth. It may also indicate a much faster creation process to have produced such large quantities of the gas in the first place.

ESA: ExoMars Methane Detection

The priority for the ESA ExoMars is mission is to map trace gases in the atmosphere of Mars, distinguishing individual chemical species down to concentrations of just a few parts per billion.

Of these gases, one in particular attracts special attention: methane. Discovered on Mars in 2003, it happens to be a possible ‘biomarker’, a gas that is readily produced by biological activity.

Understanding whether the methane comes from life or from geological and volcanic processes takes precedence. “The methane is the anchor point around which the science is to be constructed,” says ESA spokesperson Vago.

Adding to the mystery is that methane was found to be concentrated in just three locations on Mars, and then disappeared much faster from the atmosphere than scientists were expecting.

This points to an unknown destruction mechanism much more powerful than any known on Earth. It may also indicate a much faster creation process to have produced such large quantities of the gas in the first place.