Mars Rover Reaches Victoria Crater
The Mars rover Opportunity reached the rim of a deep crater Wednesday after an arduous 21-month trek, marking a milestone in its exploration for clues about the Martian past.
Scientists marveled at the black-and-white-images beamed to Earth by the robot geologist showing the crater interior complete with hanging rocky cliffs and rippling sand dunes on its floor.
"We made it!" said rover principal scientist Steve Squyres of Cornell University.
The road to Victoria Crater, a half-mile wide and 230-foot deep impact crater, was tough. The six-wheeled Opportunity drove for almost two years through what scientists called a "wasteland." At one point, it spent five weeks stuck hub-deep in a slippery sand dune before freeing itself.
Victoria, with its exposed walls of thickly layered rocks, is a treasure trove for scientists trying to determine whether the rocks were formed in shallow lakes, which might suggest Mars once could have been hospitable to life.
"The big payoff is getting to the rock record," said deputy principal investigator Ray Arvidson of Washington University in St. Louis.
Opportunity will spend a day looking for a more favorable spot around the rugged rim to take a sweeping panorama of the vista. Meanwhile, scientists are plotting Opportunity's next move and analyzing the images to find the safest route for the rover to enter, keeping in mind that it might not make it out alive.
"We have an aging rover and we want to squeeze as much out of it as we can," Squyres said.
Opportunity and its twin, Spirit, have been exploring opposite sides of Mars since landing in 2004. Both uncovered geologic evidence of past water activity on the planet.
Victoria is by far the largest crater visited by Opportunity to date. It is 40 times larger than Eagle Crater where the rover landed and five times bigger than Endurance Crater, which it spent six months studying in 2004.
The rover reached the crater in Mars' Meridiani Planum region on its 951st day of exploration, according to NASA.
Communication with the rovers will be limited next month when Mars passes behind the sun. During that time, the rovers will not perform any heavy-duty tasks like driving. Instead, they will stay put, sampling the atmosphere or imaging surroundings.
The rovers, managed by NASA's Jet Propulsion Laboratory in Pasadena, have outlasted their primary, three-month mission. This week, the space agency extended the rovers' mission for at least one more year.