Mars rovers raring to go on new adventures

By Leonard David

Senior space writer

updated 2:58 p.m. ET Dec. 28, 2006

NASA’s Opportunity and Spirit rovers are on the prowl on Mars. Science teams are plotting out new escapades for the twin robots — new destinations certain to reveal more secrets from the Red Planet.

Within Meridiani Planum, the Opportunity rover is relaying great pictures of Victoria Crater and its walls, said Steve Squyres, lead scientist of the Mars Exploration Rover project from Cornell University in New York.

So far, the story at Victoria is surprisingly similar to what rover scientists saw at Endurance Crater, a feature they closely studied for months back in 2004.

Squyres told Space.com that the rover’s Panoramic Camera, or Pancam, is telling Mars researchers that the rocks in the crater are mostly “fossilized dunes” — with layering that preserves clear evidence of ancient transport by wind.

Opportunity’s Mini-Thermal Emission Spectrometer has revealed that this material is sulfate-rich all the way down, Squyres said. Mini-TES characterizes the Martian terrain by using thermal infrared spectroscopy.

“So the picture we got back at Endurance, with a sulfate-rich dune field and lots of acidic groundwater, seems to apply here as well … several kilometers to the south,” Squyres added. “This was a big, long-lived dune field and there was lots of water here.”

Into Victoria Crater
What rover scientists may learn when Opportunity steers down inside the crater is anybody’s guess. But first, finding a driveway into Victoria is high on the priority list.

“So far we have found two safe entry routes into Victoria. Those are Duck Bay and Bottomless Bay. We have not yet confirmed that either is a safe exit route, but they both have potential,” Squyres advised.

Opportunity is continuing with its scenic tour of the rim of Victoria Crater, said William Farrand, a research scientist at the Space Science Institute in Boulder, Colo. He is also a member of the rover science team.

“We have been getting some spectacular panoramas of the promontories and inner rim of Victoria. We are also in the process of building up images for a fabulous stereo model of the crater,” Farrand told Space.com.

It is still a bit early, Farrand said, for rover science team members to assess the totality of the geologic story contained in the walls of Victoria. Doing so calls for detailed inspection of the stratigraphy of the walls — an assessment of strata, or layers.

“We are really taking a methodical approach to mapping out the stratigraphy exposed in the walls of the crater. Once we’ve gotten further around, I think we will have a better understanding of what that stratigraphy is telling us,” he said.

Spirit: Back to Home Plate
On the other side of Mars, at Gusev Crater, scientists are preparing to steer the Spirit Mars rover back to a region called “Home Plate” — a still-baffling formation near the Columbia Hills.

At the moment, Spirit has been busy looking at a target tagged “Esperanza” — the first “vesicular” basalt that has undergone detailed scrutiny.

NASA / JPL-Caltech The Spirit rover is studying a type of rock known as vesicular basalt, which contains little Swiss-cheese-like voids.

Vesicular basalts form when dissolved gas in a lava comes out of solution, “like bubbles in soda,” Squyres tutored, creating little Swiss-cheese-like voids within the rock.

“We’ve seen lots of vesicular basalts at Gusev, particularly around Home Plate, and this is our first chance to really find out what they are made of and how they may or may not be related to Home Plate,” Squyres explained.

Squyres said that Spirit is likely to stay in the vicinity of Home Plate for a long time.

From overhead, NASA’s Mars Reconnaissance Orbiter has used its High Resolution Imaging Science Experiment camera, known as HiRISE, to sharp-shoot the site that Spirit is now appraising.

“The recent HiRISE image of the Spirit site has shown us that there are many more scientifically interesting targets around Home Plate than we realized. Some of these features are difficult to spot from ground level,” Squyres pointed out.

The powerful HiRISE camera has found things that Mars rover scientists hadn’t realized were there before. “So, having found our way with much difficulty to such a target-rich environment, we’re going to work it for all it’s worth,” Squyres said.

MORE FROM SPACE

Space Section Front

Month in space: Powerful pictures Astronauts land with families on their minds Cosmic Log: Signs of Mars life? ... and more Powerful laser simulates stellar jet Solar tsunamis are real, NASA says Rocket man fails to fly from Morocco to Spain Is case finally closed on 1965 UFO mystery? Space telescope to probe sun’s atmosphere Space agencies argue over delayed launch Cosmic Log: Play the galactic slots Space Section Front   Add Space headlines to your news reader: