NASA scientists have showed off their first color "post card" of Mars taken by the robot explorer Spirit, a high-definition portrait revealing the rocky, wind-swept surface of the red planet in greater detail than ever seen before.
The photograph, actually a mosaic of a dozen three-color frames shot by Spirit's twin panoramic cameras, brought into sharp focus such vivid details as the shape and texture of rocks, the soil trails left by dust devils, nearby hills, and a tantalizing but distant mesa.
One of the most intriguing features noticed by scientists was a darkened patch of the martian surface at the edge of the lander, where the soil had been scraped by Spirit's air bags, leaving a crinkled pattern with a mud-like cohesive appearance.
"It looks like mud but it can't be mud," said Steven Squyres, the principal investigator for the team at NASA's Jet Propulsion Laboratory. "It's very cohesive. It holds together well."
The picture also revealed that the surface of the rocks surrounding Spirit in its landing site at Gusev Crater appeared to have been worn clean by the sand-blasting effects of high winds. A close-up of one small rock showed it to be pitted with tiny craters of its own.
Jim Bell, the team's leading camera specialist, said the "post card" image was 16 times higher resolution than the earlier black-and-white panoramic photos taken by Spirit's navigation cameras and three to four times sharper than the best pictures ever shot on Mars before, those taken by the Mars Pathfinder mission in 1997.
Still, scientists said the best is yet to come. Tuesday's 12-million-pixel photo, though higher definition than earlier pictures, represents about one-eighth of the entire 360-degree panorama that the twin pan cams are capable of shooting.
In a matter of days, the JPL teams expects to acquire a full 360-degree shot in three-dimensional, four-color, splendor, Bell said.
"This is just the tip of the iceberg," Squyres added.
Earlier on Tuesday, the mission managers at JPL received a telephone call from President Bush, who congratulated the team on their accomplishments.
"Then we had a little chat about quantum physics and string theory," joked JPL director Charles Elachi.