spacetoday.net: Mars rover discoveries continue

Posted: Sat, Jun 26, 2004, 1:16 PM ET (1716 GMT)
Mars Exploration Rover (NASA/JPL)

NASA's twin Mars Exploration Rovers, operating on the surface for over five months now, continue to make new discoveries, as one finds a hematite-laden rock while the other discovers new sedimentary layers. The rover Spirit, on the edge of the Columbia Hills, found a bizarrely-shaped rock dubbed "Pot of Gold" that contains the hematite, a mineral usually formed in the presence of water. The rock's odd shape suggests that it has undergone some kind of weathering process, although whether that weathering is mechanical or chemical in nature remains unclear. On the other side of the planet, the rover Opportunity has discovered new layers of what appear to be sedimentary rocks within the crater Endurance. Those layers suggest that this region of the planet may have exposed to liquid water for a longer period of time.