ExoMars Trace Gas Orbiter analyses the martian atmosphere. Credit: ESA/ATG medialab
At this very moment, eleven robotic missions are exploring Mars, a combination of orbiters, landers, rovers, and one aerial vehicle (the Ingenuity helicopter). Like their predecessors, these missions are studying Mars’ atmosphere, surface, and subsurface to learn more about its past and evolution, including how it went from a once warmer and wetter environment to the freezing, dusty, and extremely dry planet we see today. In addition, these missions are looking for evidence of past life on Mars and perhaps learning if and where it might still exist today.
One particularly interesting issue is how the atmosphere of Mars – primarily composed of carbon dioxide (CO2) – is relatively enriched with Carbon-13 (13C), aka. “heavy carbon.” For years, scientists have speculated that the ratio of this isotope to “light carbon” (12C) might be responsible for organics found on the surface (a sign of biological processes!). But after analyzing data from the ESA’s ExoMars Trace Gas Orbiter (TGO) mission, an international team led by The Open University determined that these organics may be “abiotic” in origin (i.e., not biological).
Coordination between countries in space exploration is widespread. However, sometimes that coordination falls apart. In most cases, that failure is due to budgetary constraints. But in more recent times, it is due to geopolitical ones. Specifically, western space agencies have begun to cut ties with Roscosmos, the Russian space agency, on every program excluding the International Space Station, which is still operating normally. One of those project casualties is the timeline of the oft-delayed Exomars rover, Rosalind Franklin.
A computer generated view of Mars, with an area including Gale Crater beginning to catch morning light. Image Credit: NASA/JPL-Caltech
The existence of water on Mars is a contentious subject. We know there used to be water on the surface of the planet, though it’s long gone now. We know there’s frozen water underground in the world, and we know there’s water vapour in the air. But life needs liquid water.
Could there be liquid water on Mars?
A new study shows how salty water could emerge from the atmosphere onto Mars’ surface under the right conditions.
An unusual crater on Mars, as seen by the CaSSIS camera onboard the ESA/Roscosmos ExoMars Trace Gas Orbiter (TGO) on 13 June 2021 in the vast northern plains of Acidalia Planitia. Credit: ,ESA/Roscosmos/CaSSIS,
Is this a closeup look at a tree stump, or an orbital view of an impact crater? At first glance, it might be hard to tell. But this image of a crater on Mars provides planetary scientists almost the same kind of climate history data about the Red Planet as tree rings provide to climate scientists here on Earth.
This picture was taken by the Colour and Stereo Surface Imaging (CaSSIS) camera onboard the ESA/Roscosmos ExoMars Trace Gas Orbiter (TGO), which arrived at Mars in 2016 and began its full science mission in 2018.
Mosaic of the Valles Marineris hemisphere of Mars, similar to what one would see from orbital distance of 2500 km. Credit: NASA/JPL-Caltech
For generations, humans have dreamed of the day when we might set foot on Mars. For many others, the dream has been one of settling on Mars and creating an outpost of human civilization there. Today, it looks as though both of these dreams are getting closer to becoming a reality, as space agencies and the commercial space industry are deep into planning regular crewed missions to the Red Planet. And when planning for long-duration missions to destinations in deep space, a vital aspect is assessing the local environment.
For example, missions to Mars will need to be as self-sufficient as possible, which means using local resources to meet the needs of the mission and astronauts – a process known as in-situ resource utilization (ISRU). According to new data from the ESA-Roscomos ExoMars Trace Gas Orbiter (TGO), the massive equatorial canyon known as Valles Marineris (Valley of Mars) contains vast deposits of ice that have remained hidden to scientists until now.
In about a year (Sept. 20th, 2022), the Rosalind Franklin rover will depart for Mars. As the latest mission in the ESA’s and Roscosmos’ ExoMars program, Rosalind Franklin will join the small army of orbiters, landers, and rovers that are working to characterize the Martian atmosphere and environment. A key aspect of the rover’s mission will involve drilling into the Martian soil and rock and obtaining samples from deep beneath the surface.
To prepare for drilling operations on Mars, the ESA, Italian space agency (ASI), and their commercial partners have been conducting tests with a replica – aka. the Ground Test Model (GTM). Recently, the test model completed its first round of sample collection, known as the Mars Terrain Simulation (MTS). The rover drilled into hard stone and extracted samples from 1.7 meters (5.5 feet) beneath the surface in a record-breaking feat.
A little over a week ago (February 18th, 2021), NASA’s Perseverance rover landed in the Jezero crater on the surface of Mars. In what was truly a media circus, people from all over the world tuned to watch the live coverage of the rover landing. When Perseverance touched down, it wasn’t just the mission controllers at NASA who triumphantly jumped to their feet to cheer and applaud.
In the days that followed, the world was treated to all kinds of media that showed the surface of Mars and the descent. The most recent comes from the Trace Gas Orbiter (TGO), which is part of the ESA-Roscosmos ExoMars program. From its vantage point, high above the Martian skies, the TGO caught sight of Perseverance in the Jezero crater and acquired images that show the rover and other elements of its landing vehicle.
In the course of studying Mars, scientists have come to identify some key similarities to Earth’s own. One notable example is the way our atmospheres interact with sunlight to produce dazzling displays of energy. On Earth, these include not just the aurorae near the polar regions (Aurora Borealis and Australis), but the constant green glow that is the result of oxygen molecules interacting with sunlight (aka. “airglow”).
On Earth, airglow can be seen “edge-on” from space, as exemplified by the many spectacular images that are taken by astronauts aboard the International Space Station (ISS). This phenomenon was recently observed around Mars for the first time by the ESA’s Trace Gas Orbiter (TGO), which arrived at Mars in 2016 a part of the ExoMars program. Like aurorae, this observation is yet another example of how Mars is “Earth’s Twin.”
On October 19th, 2016, the NASA/ESA ExoMars mission arrived at the Red Planet to begin its study of the surface and atmosphere. While the Trace Gas Orbiter (TGO) successfully established orbit around Mars, the Schiaparelli Lander crashed on its way to the surface. At the time, the Mars Reconnaissance Orbiter (MRO) acquired images of the crash site using its High Resolution Imaging Science Experiment (HiRISE) camera.
In March and December of 2019, the HiRISE camera captured images of this region once again to see what the crash site looked like roughly three years later. The two images show the impact crater that resulted from the crash, which was partially-obscured by dust clouds created by the recent planet-wide dust storm. This storm lasted throughout the summer of 2019 and coincided with Spring in Mars’ northern hemisphere.
On October 19th, 2016, the European Space Agency’s Exobiology on Mars (ExoMars) mission established orbit around Mars. Consisting of the ExoMars Trace Gas Orbiter (TGO) and the Schiaparelli lander, the purpose of this mission is to investigate Mars for past signs of life. And whereas the Schiaparelli unfortunately crashed during deployment, the TGO has managed to begin its mission ahead of schedule.
A few weeks ago, the satellite achieved a near circular orbit around Mars after performing a series of braking maneuvers. Since that time, the orbiter’s Color and Stereo Surface Imaging System (CaSSIS) took a stunning image of the surface. This picture was not only the TGO’s first image of Mars, it was also a test to see if the orbiter is ready to being its main mission on April 28th.
The image captured a 40 km- (25 mi) long segment of the Korolev Crater, which is located high in Mars’ northern hemisphere. The image was a composite of three images in different colors that were taken simultaneously on April 15th, 2018, which were then assembled to produce this color image. The bright material that appears at the edge of the crater is water ice.
The ExoMars Colour and Stereo Surface Imaging System, CaSSIS, captured this view of the rim of Korolev crater (73.3ºN/165.9ºE). Copyright ESA/Roscosmos/CaSSIS
As Antoine Pommerol, a member of the CaSSIS science team working on the calibration of the data, explained in a recent ESA press release:
“We were really pleased to see how good this picture was given the lighting conditions. It shows that CaSSIS can make a major contribution to studies of the carbon dioxide and water cycles on Mars.”
Prior to the test phase, the camera team transmitted new software to the TGO, and after a few minor issues, they determined that the instrument was ready to work. The camera is one of four instruments on the TGO, which also carries two spectrometer suites and a neutron detector. The spectrometers began their science mission on April 21st by taking the first sample of the atmosphere to see how its molecules absorb sunlight.
By doing this, the TGO hopes to determine the chemical composition of Mars atmosphere and find evidence of methane and other trace atmospheric gases that could be signatures of active biological or geological processes. Eventually, the camera will help characterize features on the surface that could be related to trace gas sources. Hence the importance of this recent test.
ExoMars’ Trace Gas Orbiter (TGO) and Schiaparelli lander seperating in orbit of Mars. Credit: ESA/ATG medialab
“We aim to fully automate the image production process,” said Nicolas Thomas, the camera’s principal investigator from the University of Bern. “Once we achieve this, we can distribute the data quickly to the science community for analysis.”
A lot of challenges lie ahead, which includes a long period of data collection to bring out the details of rare (or yet to be discovered) trace gases in Mars’ atmosphere. This is necessary since trace gases (as the name would suggest) are present in only very small amounts – i.e. less than 1% of the volume of the planet’s atmosphere. But as Håkan Svedhem – the ESA’s TGO project scientist – indicated, the test image was a good start.
“We are excited to finally be starting collecting data at Mars with this phenomenal spacecraft,” he said. “The test images we have seen so far certainly set the bar high.”
By 2020, the second part of the ExoMars mission is scheduled to launch. This will consist of a Russian surface platform and a European rover landing on the surface in support of a science mission that is expected to last into 2022 or longer. Alongside NASA’s proposed Mars 2020 rover, the Red Planet is due to have several more visitors in the coming years!
