Surprises in Clearest Mars Photos Yet
NASA’s Spirit rover has sent the clearest, sharpest picture ever taken on the surface of another planet, a “spectacular” postcard from Mars that is two to three times as sharp as similar photos from the earlier Viking and Pathfinder missions.
The photo shows about an eighth of the Gusev Crater region around the lander, but it is providing researchers with a great deal more information than the black-and-white images returned a day earlier.
The image “is spectacular, but this is not the best this camera can do,” said James Bell of Cornell University, who was in charge of the camera’s development.
The panoramic camera will provide high-definition pictures equivalent to those seen now on expensive TV sets, and will also provide three-dimensional images.
“If you were a human with 20/20 vision standing on Mars, this is what you would see,” he said. “My reaction has been one of shock and awe.”
The picture, a mosaic of 12 images, has yielded some surprises, said Cornell’s Steve Squyres, the mission’s principal investigator. “We’re trying to puzzle it out scientifically.”
The photo reveals a broad variety of rocks, but “the rock distribution is markedly different from what we have seen anywhere else [on Mars],” he said. “There are far fewer large rocks.”
The surfaces of the rocks are remarkably smooth, he said, and the shapes are varied -- some of them round and some of them quite angular. “The way in which this tends to come about geologically is if you have a very strong, very fine-grained rock that gets broken up by some process -- we don’t know what yet -- and then is exposed for a long period of time to sandblasting,” he said.
Most of the rocks have dark tails of debris, a shadow zone downwind from the rocks produced by the near-constant air flow. “We’ve landed in a fairly windy place,” Squyres said. He speculated that the dark areas could be largely free of the fine dust that covers most of the Martian surface, exposing the rock underneath.
“This may be similar to the darks trails produced by dust devils,” the mini-tornadoes common on Mars’ surface, he said.
The horizon in the photo is 3 to 3.5 miles from Spirit. The mesa in the background is 15 to 20 miles away, but rises above the horizon because it is several hundred yards high. The largest rocks in the foreground are about 8 inches wide.
A large depression on the right-hand side is probably similar to the one researchers have dubbed Sleepy Hollow. And the terrain appears to be scattered with impact craters.
The most mysterious part of the landscape is at the rover’s feet -- the area where its air bags were retracted after landing.
It looks to researchers like there is a layer of “strangely cohesive” material that breaks away in pieces. “It’s not like anything I have seen before.... It looks like mud, but it can’t be mud” because there is no free water, Squyres said.
“The way in which this surface has responded to dragging the air bags is bizarre,” he said. “I don’t understand it; nobody on the team understands it.”
The mission control team at the Jet Propulsion Laboratory in Pasadena, meanwhile, is proceeding with its methodical check of Spirit and continues to characterize the rover as being in good condition.
One minor problem is that the Martian atmosphere is a little warmer than expected, perhaps as much as 20 degrees Fahrenheit, because of dust in the air that is absorbing sunlight.
As a result, the rover itself is running about 9 degrees hotter than expected. The rover’s batteries and electronics also generate heat. To compensate, on Monday the rover team skipped one scheduled communication session with a Mars orbiter, said Jennifer Trosper, project system engineer. Transmitting data generates a substantial amount of heat.
On Tuesday, she added, the team planned to give Spirit a siesta to allow it to cool down.
President Bush called JPL about 8 a.m. Tuesday and spent about 10 minutes chatting with the rover team, said JPL director Charles Elachi. “He complimented the team and said they represent the best the nation has to offer,” Elachi said.
Bush called the landing “a proud moment for all Americans -- an inspirational moment,” Elachi added.
Also on Tuesday, NASA administrator Sean O’Keefe announced plans to name the Spirit landing site in honor of the seven astronauts who died in the space shuttle Columbia disaster in February.
A memorial plaque noting the name -- Columbia Memorial Station -- was attached to Spirit before launch.
