The chances of finding Martian fossils just went up.
Mars is back in the headlines, and this time the chances of finding fossil life on the Red Planet have increased.
Last month a team led by Munir Humayun of Florida State University reported on the oldest Martian rock discovered so far. The meteorite, found last year in North Africa, dates from about 4.4 billion years ago, a mere 100 million years or so after Mars became a planet. Named “Black Beauty” because of its dark glossy appearance, the rock known formally as NWA7533 originated when water flowed on the surface of Mars—a time when we would expect that life arose on Mars, if it ever did. Black Beauty’s elemental and mineralogical composition gives us a glimpse of environmental conditions during that intriguing period of Martian history.
It appears that the meteorite came from the southern highlands of Mars, a region about which we know relatively little. The landscape there is covered with craters, the largest of which is the Hellas Basin, about seven kilometers deep and more than 2,000 km across. The basin resulted from an impact that must have had planet-changing repercussions at a time when Mars was warmer ...