This image from the Mars Orbiter Camera aboard NASA's Mars Global Surveyor spacecraft shows an overview of Victoria Crater. The Mars Rover Opportunity has arrived at the rim of the big crater, NASA said on Sept. 27, 2006. (Photo: NASA/Reuters) Photo Gallery >>>

    BEIJING, Sept. 28 (Xinhuanet) -- The Mars Rover Opportunity has edged closer to the rim of a large crater that scientists thought if could never reach after an arduous 21-month trek, said NASA Wednesday.

    Scientists are increasingly confident that their robotic explorer had reached a scientific gold mine that will dramatically increase their understanding of the planet's history -- especially whether water still exists there.

    NASA scientists said the rover came within about 15 feet (about 4.5 meters) of Victoria Crater's rim and was scheduled to climb over a small sand dune Wednesday night and stop right at the crater's edge.

    "The pictures we got tell us there is a tremendous amount of geologic information hidden in that crater," said Steven Squyres of Cornell University, principal science investigator for the mission.

    "What secrets it actually holds we won't know till we begin to get the data. But yesterday's picture alone makes the voyage worthwhile. This is a geologist's dream come true.

    "Those layers of rock, if we can get to them, will tell us new stories about the environmental conditions long ago," he continued. "We especially want to learn whether the wet era that we found recorded in the rocks closer to the landing site extended farther back in time."

    Opportunity has lasted 10 times as long as the 90 days NASA originally projected. It has been exploring Mars since January of 2004 and traveled more than 5.7 miles (about 9.2 km).

    The rover will spend a day looking for a more favorable spot around the rim to take a panorama photo 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 the crater.

    Opportunity and Spirit, the other rover, have been exploring opposite sides of Mars since landing in 2004. Both uncovered geologic evidence of past water activity on the planet.

    The rovers, managed by NASA's Jet Propulsion Laboratory in Pasadena, have outlasted their primary, three-month mission. According to the space agency, the rovers' mission will be extended for at least one more year. Enditem

    (Agencies)

    Related: Mars rover Opportunity nears Martian bowl goal

    WASHINGTON, Sept. 6 (Xinhua) -- NASA's Mars rover Opportunity was closing in on what may be the grandest overlook and richest science trove of its long mission, NASA announced Wednesday at its official website.

    During the next two weeks, the robotic geologist ¨C Opportunity was likely to reach the rim of a hole in the Martian surface wider and deeper than any it has visited. The crater, known as "Victoria," is approximately 750 meters wide and 70 meters deep. Full story>>