Remote-controlled X-ray spectrometer on surface of Mars

One of the most exciting recent scientific discoveries is that Mars was possibly once wet and salty, suggesting an environment that could serve as a candidate for early life. The two Mars Rovers, Sprit and Opportunity, have been collecting large amounts of data on the soil, rock and atmosphere by utilizing state-of-the-art analytical instruments including an X-ray spectrometer, which recently determined the major and minor elements of soil and rock samples taken from Meridiani Planum. For more information, see the paper, "Chemistry of Rocks and Soils at Meridiani Planum from the Alpha Particle X-ray Spectrometer", R. Rieder et al., Science, 306, 1746-1749 (2004).