NASA’s Curiosity rover has found evidence that chemistry in the surface material on Mars contributed dynamically to the makeup of its atmosphere over time. It’s another clue that the history of the Red Planet’s atmosphere is more complex and interesting than a simple legacy of loss.
The findings come from the rover’s Sample Analysis at Mars, or SAM, instrument suite, which studied the gases xenon and krypton in Mars’ atmosphere. The two gases can be used as tracers to help scientists investigate the evolution and erosion of the Martian atmosphere. A lot of information about xenon and krypton in Mars’ atmosphere came from analyses of Martian meteorites and measurements made by the Viking mission.
“What we found is that earlier studies of xenon and krypton only told part of the story,” said Pamela Conrad, lead author of the report and SAM’s deputy principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “SAM is now giving us the first complete in situ benchmark against which to compare meteorite measurements.”
Of particular interest to scientists are the ratios of certain isotopes – or chemical variants – of xenon and krypton. The SAM team ran a series of first-of-a-kind experiments to measure all the isotopes of xenon and krypton in the Martian atmosphere. The experiments are described in a paper published in Earth and Planetary Science Letters. [More at links]