Green Minerals on the Red Planet

Scientists have discovered clues that the green mineral olivine, which also takes the form of the gemstone peridot, exists on Mars. Olivine is an important ingredient in Earth’s upper mantle, the region that lies beneath the planet’s outer “crust”—somewhat like the chocolate in a peanut M&M.

Olivene is easy to find in rocks on our planet’s surface, although it eventually breaks down, or “weathers” over time. Currently, Mars is much colder and drier than Earth, but it may not always have been that way. If scientists can figure out how long the olivine has been exposed on Mars’ surface, they might better understand Mars’ ancient climate. For example, if the olivine has been there since Mars’ younger days, then the climate there has probably been cold and dry since then too.

Todd M. Hoefen of the United States Geological Survey and colleagues identified the olivine-rich rocks on Mars using special measurements taken by an instrument called the Thermal Emission Spectrometer, aboard the Mars Global Surveyor. The scientists report their discovery in the 24 October issue of the journal Science, published by AAAS, the non-profit science society.

For more information, read Science for Kids. See also, Kids' Science News from AAAS.

—Kathy Wren

23 October 2003