Spirit Hits the Sweet Spot
January 5, 2004
NASA's Mars rover Spirit has landed in Gusev Crater, and it is beaming pictures back to Earth.

NASA's Mars rover Spirit landed yesterday just where scientists hoped it would go: inside Gusev Crater, in a vast flatland perfect for roving. And, as a bonus, Mars dust is not a problem. 

"My hat is off to the navigation team because they did a fantastic job of getting us right where we wanted to be," says Steve Squyres of Cornell University, principal investigator for the science payload. "We hit the sweet spot. We wanted someplace where the wind had cleared [the dust] off the rocks for us--and this is it." 

The region around Spirit's landing site appears to be criss-crossed by the trails of dust devils, which have carried away dust and left gravel behind. Dust-free rocks are good, because they're easier for the rover's geology instruments to penetrate and analyze.

Spirit parachuted into Gusev Crater on January 4th at midnight Eastern Standard Time. Mission planners chose to land there because, from orbit, the crater appears to be a dried up lake bed. If, indeed, it was filled with liquid water long ago, then it might have been a habitat for ancient martian life. (Read the Science@NASA story "Destination: Gusev Crater" for more information.) 

To the delight of researchers, Spirit's first pictures of its surroundings resemble dried up lake beds on Earth. The terrain is flat and peppered with small rocks. No one knows if the resemblance is more than superficial. Spirit will use its geology tools to find out. 

"What we're seeing is a surface that is remarkably devoid of big boulders, at least in our immediate vicinity, and that's good news because big boulders are something we would have trouble driving over," Squyres said. "We see a rock population that is different from anything we've seen elsewhere on Mars, and it comes out very much in our favor." The flatland is well suited for roving. 

At the moment, the rover remains perched on its lander platform, and the next nine days or more will be spent preparing for egress, or rolling off, onto the martian surface. The platform is tilted by only two degrees, and the front deck is only about 37 cm off the ground. With no large rocks blocking the way, the rover is in good position for egress. 

The rover's initial images have excited scientists about the prospects of exploring the region after the roll-off. "This is our new neighborhood," says Squyres. And for the next three months, if all goes well, Spirit will explore it, searching the rocks and soil for clues to the mystery of Mars water, and maybe, martian life.