LOS ANGELES, Aug. 26 (Xinhuanet) -- The rover Spirit is now sitting atop the summit of a hill in southern Mars, mission scientists were overjoyed Friday in achieving the exploration high point.

    The robotic rover had driven more than 9 months before it reached the top of Husband Hill, about 80 meters above the floor of Gusev Crater, said Steve Squyres, lead scientist working with the rover mission of US space agency NASA.

    The Husband Hill, one of the Columbia Hills around the Gusev Crater, is named after Rick Husband, an astronaut killed in shuttle Columbia's disaster in 2003.

    Spirit's climb and arrival at the summit is a milestone, said Squyres. A lot of credit goes to the rover planners, the engineerswho plot out the drives and movements of the instrument-tipped mechanical arm carried by each of the Mars rovers.

    As Spirit sits atop the summit of Husband Hill, mission scientists have decided to have it shoot several panoramas from several spots on the borders of the summit plateau.

    From its new lookout point, Spirit can image down into the inner basin to the south and get "the greatest view", said WilliamFarrand, a mission scientist.

    The summit itself will provide good science, Farrand said, specifically as to wind transport of fine grained materials.

    The inner basin area of the Columbia Hills contains a broad range of interesting geological targets, including the feature dubbed "Home Plate" and other possible layered outcrops. These features suggest that the hills contain rock layers.

    Layered rocks are an important scientific target on the Red Planet, because they can form through the action of water. Spirit might investigate the layers to determine whether they are water-deposited sedimentary rock.

    Rover science teams are prepared to do a "full summit campaign"of observations, Farrand said.

    Spirit has driven nearly 5,000 m since it touched down on the 3-billion-year-old volcanic plains of Gusev Crater in January, 2004.

    Earlier, It just finished a thorough investigation of a rock called Assemblee, which has an unusual composition and the highestlevels of the metal chromium ever discovered in a rock on Mars.

    As Spirit surveys its Gusev crater site, the robot's twin, the rover Opportunity, is exploring Meridiani Planum on the other sideof the planet. Opportunity is wheeling its way toward Erebus Crater, a feature some 100 meters in diameter.

    Both rovers, far surpassing their initial warranty of 90-days, have collected evidences of water's existence in Martian history, said NASA's Jet Propulsion Laboratory (JPL), which is operating the Mars exploration project. Enditem