By Chris Skeldon 
Since landing on Mars on February 18, 2021, NASA's Perseverance rover has already obtained 24 rock and dust samples to send back to Earth. However, the collection tubes store something beyond these geological treasures: some Martian air, which is as valuable to scientists as soil fragments – called regolith.
The rock cores sampled by the equipment likely contain information about Mars' distant past and the possible existence of life on the planet. The air trapped inside the tubes could be just as important, as researchers believe it could reveal new clues about the Martian atmosphere.
“Air samples from Mars will give us information not only about the current climate and atmosphere, but also about how they have changed over time,” Brandi Carrier, a planetary scientist at NASA's Jet Propulsion Laboratory, said in a statement. statement. “This will help us understand how climates different from our own evolve.”
Analysis of the Martian air could provide valuable information
These samples are sealed in titanium tubes that allow “Head space“, or “extra airspace” around the rocky material, giving scientists the opportunity to study the interaction between the Martian atmosphere and the planet's surface.
Hey Head space It could also detect trace gases in the Martian atmosphere. Although it is mainly composed of carbon dioxide, it may contain small amounts of other ancient gases dating back to the planet’s formation. This could provide valuable information about the size and toxicity of dust particles, allowing scientists to better assess risks for future manned missions to Mars.
“Gas samples have a lot to offer Mars scientists,” said Justin Simon, a geochemist at NASA's Johnson Space Center in Texas, who is part of an international group of experts who decide which samples the rover should collect. “Even scientists who don't study Mars will be interested, because this will shed light on how planets form and evolve.”
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Samples are collected and stored for eventual return to Earth as part of the expedition Mars sample return. However, it will be many years before they can be analyzed in terrestrial laboratories, due to the cost and complexity of the return mission (learn more here).
When (or if) these samples reach Earth, scientists will extract the gas using a cold trap, where it will condense into a solid or liquid. A similar process was used to study air captured in samples from the Moon during the Apollo 17 mission in 1972.
Using samples from Mars, researchers also hope to better understand the amount of water vapor present near the surface of Mars, and thus why ice forms in certain locations on the planet. Water vapor captured in air samples could provide valuable data about the evolution of the water cycle on Mars over time.
The rover studies the environment for future human missions
The Perseverance rover's mission isn't just about collecting samples. It is equipped with an array of advanced scientific instruments, including high-resolution cameras, lasers to analyze rocks, and systems to study the climate and geology of Mars in unprecedented detail. These instruments allow scientists to make discoveries in real time while waiting for samples to return to Earth.
Additionally, the equipment helps pave the way for future manned missions to Mars. Analysis of Martian air and dust could reveal environmental challenges astronauts will face, such as the toxicity of dust particles and the composition of the atmosphere.
With this information, engineers can develop techniques and strategies to ensure the safety and success of future human exploration on the Red Planet.