NASA Rover Seeks Signs of Martian Water

Feb 24, 2004
by ANDREW BRIDGES, AP Science Writer

LOS ANGELES - NASA's Opportunity rover drilled into a rocky outcrop on Mars Tuesday as scientists prepared to examine the stone to learn whether it was formed under watery conditions that may have been favorable to life.

The wheeled robot used its rock-abrasion tool to grind 0.16 inch into the surface of a rock dubbed "El Capitan," project manager Richard Cook said.

The rover then began to inspect the round hole with other instruments designed to analyze the composition of the freshly exposed rock, as well as photograph it in microscopic detail.

Mission scientists were eager to learn more from the measurements, but results were expected to take several days to reach Earth.

"It's Christmas Eve and all the scientists are anxious and excited with anticipation," deputy main scientist Ray Arvidson said.

The outcrop, about the height of a street curb, rings a portion of the crater that cradles the rover. Previous microscopic images show fine layering in the rock, including "El Capitan," as well as mysterious BB-sized granules.

Scientists involved in the $820 million mission continued to mull theories of how the glossy, sandblasted rock formed, whether through volcanic eruptions, windblown dust or sediments settling out of a body of water.

The new data could settle the issue.

Halfway around Mars, Opportunity's twin rover, Spirit, continued to roll toward a crater, traveling nearly 100 feet on Tuesday. NASA planned to send the rover a short distance farther, then pause for a few days for observations, Cook said.

Spirit is about 300 feet from the crater nicknamed "Bonneville." Scientists expect the rover to reach its rim and peer into it for the first time in mid-March, Arvidson said.

Scientists consider such impact craters "windows" into the geologic past of Mars, since they can churn up rocks from deep below the surface that may contain evidence of past water activity that the two rovers were designed to seek.

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