Roving on the Red Planet
Robots tell a tale of once-wet Mars
By Ron Cowen
When Phil Christensen was 13, his family moved from the flatlands of Kansas to the foothills of southern California. He soon began backpacking in the Sierra Nevada and Joshua Tree Park, marveling at the rocky desert landscape. Thirty years later, Christensen is exploring similar terrain on another planet.
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He and his colleagues are in charge of miniature infrared spectrometers on the twin rovers that continue to explore Mars nearly 18 months after their arrival, gleaning information about rocks on the Red Planet much as field geologists learn about rocks on Earth.