Meteorite on Mars
By Ron Cowen
Opportunity, one of the twin rovers on Mars, has discovered the first meteorite on a planet other than Earth. Initial observations, taken from a distance with the rover’s thermal-emission spectrometer, indicated that the pitted, basketball-size body is a metal-rich meteorite. Driving close enough to use its X-ray and gamma-ray spectrometers, Opportunity confirmed the object’s meteorite status and revealed that it’s made mostly of iron and nickel, NASA announced on Jan. 19.
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2005/02/4798.jpg?resize=300%2C249&ssl=1)
The metallic composition indicates that the rock came from an asteroid or planetary chunk large enough for its mixture of minerals to have separated into a dense, metallic core and a lighter, rocky mantle, notes rover researcher Steve Squyres of Cornell University.