Astronomy Picture of the Day 03-23-04

Explanation: The hot surface of Venus shows clear signs of ancient lava flows. Evidence of this was bolstered by the robot spacecraft Magellan, which orbited Venus in the early 1990s. Using imaging radar, Magellan was able to peer beneath the thick perpetual clouds that cover Earth's closest planetary neighbor. Picture above, lava apparently flowed down from the top of the image and pooled in the light colored areas visible across the image middle and bottom. The lava cut a channel across the darker ridge that runs horizontally across the image center. The picture covers about 500 kilometers across. The lava originates from a caldera named Ammavaru that lies about 300 kilometers off the image top. The hot dense climate makes Venus a more difficult planet on which to land spacecraft and rovers. Venus currently sparkles as the brightest object in the western sky after sunset.

Opportunity rover bids farewell to crater home
BY SPACEFLIGHT NOW
Posted: March 22, 2004

An image from Opportunity looks back at its crater. Credit: NASA/JPL

Two months after scoring an "interplanetary hole in one" by landing inside a crater on Mars, the rover Opportunity drove out of the bowl-shaped crater Monday and sent back images of the remarkably smooth, flat terrain at Meridiani Planum.

The crater departure was first attempted Sunday, but the rover's wheels lost traction in the soil.

"NASA's Opportunity tried driving uphill out of its landing-site crater during its 56th sol. (Sunday), but slippage prevented success," mission control reported.

"The rover is healthy, and it later completed a turn to the right and a short drive along the crater's inner slope," NASA said Sunday night.

Controllers sent Opportunity along the crater rim to exit at a different spot. After Monday's successful drive, Opportunity is now sitting 9 meters (about 29.5 feet) outside of the crater.

Also Monday, the rover performed remote sensing observations between naps.

"After completing the drive out of the crater, the navigation camera imaged Opportunity's brand new view of the plains of Meridiani Planum," controllers reported Monday.

"During the martian night, rover planners will awaken Opportunity to take miniature thermal emission spectrometer observations of the ground and the atmosphere."

"Eagle Crater" is approximately 22 meters (72 feet) in diameter. Opportunity has thoroughly examined the exposed bedrock and soil samples within the crater over the past two months, providing scientists with enough data to determine that the site was once drenched in water.

Opportunity's long-range goal is driving across the plains to a much larger crater in the distance.

Another image from Opportunity showing the plains of Meridiani. Credit: NASA/JPL

New Mars rover discovery to be unveiled Tuesday
BY SPACEFLIGHT NOW
Posted: March 22, 2004

Another "major scientific finding" from the Mars Exploration Rover Opportunity mission will be announced Tuesday.

The rover is studying the Meridiani Planum region of Mars where it recently discovered evidence rocks at the landing site have been altered by water.

Tuesday's NASA news conference will be held at the agency's headquarters in Washington. The briefing begins at 2 p.m. EST (1900 GMT) with opening remarks from NASA Administrator Sean O'Keefe.

Presenting the discovery will be:

Dr. Ed Weiler, NASA's Associate Administrator, Office of Space Science
Prof. Steve Squyres, Cornell University, Ithaca, N.Y., and MER Principal Investigator
Prof. John Grotzinger, Massachusetts Institute of Technology, Cambridge, Mass, and a MER Co-investigator
Dr. Dave Rubin, U.S. Geological Survey Sedimentologist at the Pacific Science Center in Santa Cruz, Calif.
Dr. Jim Garvin, NASA Lead Scientist for Mars and the Moon, Office of Space Science, NASA Headquarters

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