A 700,000-Year Trip From Mars to Morocco

A meteorite that landed in the Moroccan desert last summer was ejected from the surface of Mars 700,000 years ago, a new study reports. The meteorite is composed of an abundance of black glass, with noble gases trapped inside. “Based on the noble gas measurements, we could calculate the ejection age of the meteorite,” said Hasnaa Chennaoui Aoudjehane, an astronomer at the Hassan II University in Casablanca, Morocco, and the study’s first author. The meteorite, called Tissint after a nearby village, is only the fifth Martian meteorite that people have witnessed falling to Earth. There are about 60 known meteorites thought to be from Mars. But Tissint is unique because it fell into the desert and suffered little damage from Earth’s environment. “We had no rain between the moment it fell and the moment it was collected,” Dr. Aoudjehane said. “It was fresh, and it is very exciting to be able to analyze this.” By analyzing the noble gases trapped in the glass, along with its oxygen isotopes and minerals, she and her colleagues were able to determine that the rock is Martian. The meteorite may have been knocked loose from Mars by an asteroid or some other large body that hit the planet, the researchers believe. The impact may have also caused some melting, creating the black glass and preserving a Mars “signature” inside the glass. Pieces of the meteorite are on display at several museums, including the Museum of Natural History of Vienna and the Natural History Museum in London. BHANOO, Syndia N. A 700,000-Year Trip From Mars to Morocco.

The New York Times. 15 out 2012.