Scientists have analyzed a meteorite found on Earth and suggest that it could come from Mars's crust at a time when the planet was still wet and volcanically active.
Carl Agee/University of New Mexico/AP
An unusual meteorite plucked from the Moroccan desert holds the potential to open a window on a critical period in the history of Mars, when the planet was undergoing a dramatic change from warm and wet – conditions potentially hospitable to life – to cold, dry, and desolate.
Unlike any Martian meteorite scientists have studied so far, the new object, tagged as NWA 7034, has a composition similar to the planet's crust. Indeed, the sample is similar to rock and soil samples seen by rovers Spirit and Curiosity – the first time scientists have been able to link a meteorite to rocks analyzed on the surface of the red planet, according to a team from the US and China formally reporting its results in Friday's issue of the journal Science.
It is the 2 billion-year-old meteorite's volcanic origin and its apparent interactions with water and the atmosphere at or near the Martian surface that may have turned it into such an intriguing a time capsule.
"Having this sample from 2 billion years ago may give us a little bit of a glimpse of what the surface conditions were like" during a poorly understood period in Mars's history, says Carl Agee, the team's leader and director of the Institute for Meteoritics at the University of New Mexico in Albuquerque.
The rock was formed during the early years of Mars's Amazonian epoch. The epoch is thought to have started between 3.5 and 1.8 billion years ago and was marked, among other things, by the formation of the solar system's largest volcano, Olympus Mons, as well as by volcanic activity elsewhere on the planet.
The 11-ounce meteorite's mix of minerals and its rubble-like composition speak to a violent beginning – rising toward the surface in an explosive, Mt. St. Helens-style volcanic eruption, Dr. Agee says.