Research Stories

by Robert Burnham

Melas Chasma, part of Valles Marineris, the "Grand Canyon of Mars." The site tucks into a small basin below the south rim of Valles Marineris. Researchers say the basin, at center, likely contains deposits left when it was once filled with a lake.

Spirit and Opportunity are still making new discoveries. NASA's two Mars rovers have been working for more than 1,300 days on the planet's surface. Their original missions were designed to last for 90 days.

Earlier this summer, Spirit was working in the geologically complex Columbia Hills within Gusev Crater. The rover found a deposit of virtually pure silica. Mini-TES (Miniature Thermal Emission Spectrometer) made the discovery. The instrument was designed by Philip Christensen of ASU's School of Earth and Space Exploration.

On Earth, silica typically forms in hot springs and volcanic environments. It can be found in the geyser pools in Yellowstone National Park. The material commonly preserves traces of microbial life. No one knows if Mars ever had life–and neither rover is equipped to detect it anyway–but the silica discovery is intriguing and suggestive.

NASA is now planning where to send its next-generation rover. The Mars Science Laboratory is dicate areas where gravel, fine sand, and dust particles predominate.