Meteorites on Mars

NASA's Mars Rovers Are Great For Finding Meteorites!

Hard to Find on Earth but Abundant on Mars?

NASA's two Mars Rovers have found some spectacular meteorites. On Earth, the only humans who are as successful at finding meteorites are professional meteorite hunters. Are meteorites that abundant on Mars or are these Rovers simply lucky?

The answer to this question has a lot to do with the environment of the two planets. The surface of Earth has an environment that is rich in oxygen and moisture - both of which are rapidly destructive to iron meteorites. A meteorite that lands on Earth's surface would rust away in a blink of geologic time. Mars, however, has very little oxygen and moisture in its atmosphere and surface soils. Meteorites that land on Mars can remain in excellent condition for millions - or even billions - of years. Mars is the perfect place to hunt for meteorites.

Mars Meteorite: Block Island

This is a picture of "Block Island," the largest meteorite yet to be found on Mars. It is about 60 centimeters across (about 2 feet) and is estimated to weigh about one-half ton. Analysis of its composition by Rover Opportunity's alpha particle X-ray spectrophotometer reveals that it is rich in iron and nickel - proof positive that it is an iron meteorite. This photo was taken by the navigation camera on NASA’s Mars Exploration Rover Opportunity on July 28, 2009. The Mars Rover drove right past the rock but NASA researchers noticed it a few days later in an image that was taken and transmitted down to Earth. So they sent Opportunity back to check out the rock and touch it with its robotic arm for an analysis. Enlarge.

Mars Meteorite: Heat Shield Rock

"Heat Shield Rock" is the first meteorite ever identified on the surface of another planet. It is a baseball-size iron-nickel meteorite discovered by NASA's Mars Exploration Rover Opportunity ON January 6, 2005. Its composition and identity as a meteorite were confirmed by the Rover's spectrophotometer - it determined that "Heat Shield Rock" was composed of iron and nickel. The Meteoritical Society originally named it "Meridiani Planum" after the location where it was found - this is the traditional naming convention for meteorites found on Earth. However, the name "Heat Shield Rock" has become more popular. It received that name because it was discovered near the location where Opportunity discarded its heat shield. How long the meteorite has been on the surface of Mars is unknown, however, it shows very little sign of rusting or other alteration. Enlarge Image.