Strange Meteorites II
 This metallic meteorite is unremarkable on its own: a mixture of iron and nickel similar to hundreds of meteorites discovered before. What sets it apart is its location: the sands of Mars. The Opportunity rover photographed it several months ago after climbing out of a large Martian crater. It is the first meteorite ever discovered on the surface of any body other than Earth. [Credit: NASA/JPL/Cornell]
The Opportunity rover discovered the meteorite early this year. It had just climbed out of a big crater and was perusing the debris from its heatshield, which protected the rover during its entry into the Martian atmosphere. The heatshield sits on a wide, sandy plain.
When Opportunity first photographed the basketball-sized rock near the heatshield, scientists thought it looked metallic. And when Opportunity analyzed its composition, they were proved right: the rock is made of iron and nickel, just like the metallic meteorites found on Earth. Scientists concluded that the rock must be a meteorite -- the first one discovered on the surface of any body other than Earth.
Opportunity made the discovery in part because the area it's studying is coated with sand but almost no rocks. That means there's a good chance that any rocks that do turn up are meteorites. It's the same reason that many of the meteorites found on Earth were discovered atop deserts and glaciers: there are no local rocks to compete with the ones from space -- including more than a dozen that came from the planet Mars.
Script by Damond Benningfield, Copyright 2005
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
|
Contact | About | Friends of McDonald | Sign up for Sky Tips
