Mars rover reaches crater floor
Published 9:00 pm Thursday, March 11, 2004
After traveling over the Martian surface for more than 30 days to reach the Bonneville crater, NASA’s Spirit rover peeked over the rim and found that the crater floor looks very much like the terrain it has already passed over, researchers said Thursday.
Notably absent in the 220-yard-diameter crater were rock outcroppings like those found by Spirit’s twin, Opportunity, halfway around Mars in a much smaller crater at Meridiani Planum.
Such outcroppings would have given the science team at the Jet Propulsion Laboratory in Pasadena, Calif., a better idea of the rock composition below the surface at Gusev Crater, where Spirit landed Jan. 3, and might have shed light on the question of whether large quantities of water once existed there.
The team has already confirmed that large quantities of water once existed at Meridiani Planum, where Opportunity landed Jan. 24.
Although the team has yet to take high-definition pictures of the interior of Bonneville crater, which might reveal unexpected details, it now seems likely that they will forego the chance to drive the rover into the crater.
If the soil in the crater “is the same stuff we’ve been on and characterized already, then we’ll go where the object of the mission suggests, which is someplace else, basically,” said JPL scientist Matt Golombek.
Instead of entering the crater, Spirit will most likely skirt its rim and then head off toward the East Hills about 1 1/2miles away from Bonneville.
The new images of the crater show a layer of dusty soil punctuated by a “rubble” of small rocks. On the far side of the crater, the images show the heat shield from Spirit’s lander, where it crashed to the surface after the lander separated from it. In the distance, the same panoramic image reveals the lander’s parachute.
The two rovers turned their cameras to the sky this week. Spirit snapped a picture of Earth about an hour before sunrise. Spirit also snapped an image of a streak across the Martian sky that team members think may be the National Aeronautics and Space Administration’s Viking 2 orbiter, which has been orbiting Mars since 1976. Earth-based engineers have been unable to communicate with the orbiter for 20 years.
Opportunity, which has continued its exploration of the small crater in which it landed, captured images of Deimos and Phobos, Mars’ two small moons, as they crossed in front of the sun. The images will help astronomers characterize the moons’ orbits more precisely, enabling the European Space Agency’s Mars Express orbiter to turn its camera toward them.
JPL project manager Jennifer Trosper said both rovers are very healthy and the team now thinks that each will survive for at least 200 Martian days. “It appears they are going to be with us for quite some time,” she said.
