Mars rover to explore crater secrets
By Michael Coren
(CNN) -- The Mars rover Opportunity is perched above a crater that researchers said could open up a window into the mysterious -- and possibly wet -- history of the Red Planet.
It has also offered scientists a stunning vista.
"In terms of sheer scenic grandeur, it is the most spectacular image we've taken," said Cornell University astronomer Steve Squyres, principal investigator for the mission. "It's like nothing else on Mars."
Rover images of the site show red, sheer cliffs rising up from the sandy Martian crater.
The depression, measuring about 490 feet (150 m) in diameter and 66 feet (20 m) deep, was formed by a powerful impact and reveals layers of underlying bedrock.
Researchers have been eager to send the rover to the site because they suspected it could yield scientific discoveries. That appears to have paid off.
"This is [fundamentally] different than anything we have seen before," said Squyres.
Researchers are most excited about the exposed layers of rock. This is the closest scientists have gotten to this kind of geological formation on Mars. Further study could shed light on how the apparently sedimentary rock --laid down by wind, water or ice -- formed on ancient Mars.
Researchers plan to spend weeks mapping the site by driving the rover around the rim of the crater. They will remotely survey the entire circumference and interior of the depression. If operators decide it is safe, Opportunity may drive into the crater and perform chemical and microscopic tests on the rocks.
Yet the scientific bonanza comes at a price. The same terrain that makes the planet's geology accessible to scientists also makes it a threat to the relatively small rover.
"There are cliffs the rover could fall over and die if we aren't careful," said Squyres. "We are gong to proceed carefully and methodically."
He stressed that there is still plenty of science to do on the plains.
To reach Endurance crater, the Opportunity rover rolled through an arid landscape of sand dunes, dust ripples and fractures. Much of that could yield more groundbreaking discoveries about the history of Mars.
Opportunity also passed by the impact site of the heat shield that protected it during its plunge through the Martian atmosphere. Engineers may be able to glean insights for future Mars missions if they see how this shield weathered the descent.
Officials at NASA's Jet Propulsion Laboratory said they would carefully weigh the benefits of entering the crater versus the risks to the rovers.
Brian Cooper, rover planner team leader, said the Endurance crater's 20-degree slope could pose a hazard to Opportunity. At Eagle crater, near the rover's landing site, a 17-degree slope had proved treacherous for the robotic explorer. The rover had to traverse the crater after slipping in the sandy soil.
"We want to do a really good job of analyzing things," Cooper said.
Opportunity finished its primary mission April 26, its 90th full day on the Red Planet. It will probably keep working through at least September.
The second rover, Sprit, on the other side of the planet, will continue scouring Mars for geologic evidence the planet was once a wetter place capable of sustaining life.
Both rovers have found evidence that Mars once held liquid water.