Reports Detail Mars Rover Clues To Atmosphere’s Past
A pair of new papers report measurements of the Martian atmosphere’s composition by NASA’s Curiosity rover, providing evidence about loss of much of Mars’ original atmosphere.
Curiosity’s Sample Analysis at Mars (SAM) suite of laboratory instruments inside the rover has measured the abundances of different gases and different isotopes in several samples of Martian atmosphere. Isotopes are variants of the same chemical element with different atomic weights due to having different numbers of neutrons, such as the most common carbon isotope, carbon-12, and a heavier stable isotope, carbon-13.
“As atmosphere was lost, the signature of the process was embedded in the isotopic ratio,” said Paul Mahaffy of NASA Goddard Space Flight Center, Greenbelt, Md. He is the principal investigator for SAM and lead author of one of the two papers about Curiosity results in the July 19 issue of the journal Science.