Fresh Martian meteorite

Tissint Martian meteorite shows distinct charring from Earth's atmosphere.

Ameteorite that streaked to Earth in a blazing fireball over the Moroccan desert is one of the freshest samples of the Red Planet's surface and atmosphere that scientists have ever seen.
Desert nomads recovered fragments of the Tissint meteorite, one of just five from Mars that have been seen during their descent, after it landed early in the morning of July 18, 2011. The space rock resembles a meteorite found in Antarctica in 1980 that was the first to show strong evidence of its Martian origin. But unlike other Martian meteorites that have sat on Earth's surface for tens or hundreds of years before being discovered, Tissint hasn't had much time to be altered by terrestrial influences.
"It's really a great sample if you're interested in studying something that has more or less been delivered straight from Mars, uncontaminated, to the Earth," says planetary scientist Carl Agee of the University of New Mexico.
Other scientists agree but don't rule out contamination entirely. "It sat around the desert for months," says planetary scientist Harry McSween Jr. of the University of Tennessee, and the meteorite probably wasn't collected under sterile conditions. "Nevertheless, it's an interesting sample, in that it is probably less altered than others we have that weren't collected immediately."

Source: Science News