Scientists suspect iron meteorites might be able to resist erosion on Mars, which may explain why some appear perched on flat ground rather than embedded in craters. In other cases, a crater may have weathered away long ago, leaving only the rock behind.

Interest in Martian life had been spurred by a now infamous announcement from the White House lawn in 1996, when President Bill Clinton declared that signs of life had been detected in a Martian meteorite found in Antarctica. That claim was later refuted—but it caused enough clamor to put the search for Martian life at the top of NASA’s agenda.

NASA's Mars rover Perseverance has uncovered rocks in a dry river channel that may hold potential signs of ancient microscopic life, scientists reported Wednesday.They stressed that in-depth analysis is needed of the sample gathered there by Perseverance ...