This illustration shows the locations and interactions of volatiles on Mars. Volatiles are molecules that readily evaporate, converting to their gaseous form, such as water and carbon dioxide. On Mars, and other planets, these molecules are released from the crust and planetary interior into the atmosphere via volcanic plumes. On Mars, significant amounts of carbon dioxide go back and forth between polar ice caps and the atmosphere depending on the season (when it's colder, this gas freezes into the polar ice caps).
Researchers are using Curiosity's 10 instruments to investigate whether areas in Gale Crater ever offered environmental conditions favorable for microbial life. JPL, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate, Washington, and built Curiosity. The SAM instrument was developed at Goddard with instrument contributions from Goddard, JPL and the University of Paris in France.