A little bit of Mars on Earth
By Ron Cowen
Sending rovers on a 500-million-kilometer journey to explore the Martian landscape isn’t the only way to uncover the history of the Red Planet. Chunks of rock that have been chipped from Mars by ancient impacts and then pulled to Earth by our planet’s gravity provide planetary scientists with rare and inexpensive opportunities to investigate the Red Planet’s past. To date, researchers have studied about 24 Martian meteorites.
The latest addition to this exclusive club was uncovered on Dec. 15, 2003, on an ice field in the Transantarctic Mountains, about 750 kilometers from the South Pole. Designated MIL03346, the 715.2-gram black rock has the mineral composition, texture, and isotope content of rocks from Mars, say scientists at the Smithsonian Institution’s National Museum of Natural History in Washington, D.C. Details of the find have been posted on a special online edition of the Antarctic Meteorite Newsletter (http://curator.jsc.nasa.gov/curator/antmet/amn/amn.htm).
The new specimen is the seventh known member of a group of Martian meteorites called the nakhlites, which scientists propose originated within thick lava flows that solidified on Mars some 1.3 billion years ago.