Mars rover at halfway point of latest trek for science work

NASA says its Mars rover Opportunity has passed the halfway point on its drive from a site where it spent 22 months to its next research destination. The rover has less than half a mile to go to finish a 1.2-mile journey dash from one crater-rim segment, where it has worked since mid-2011, to another where mission controllers intend to keep Opportunity busy doing science during the upcoming martian winter, NASA's Jet Propulsion Laboratory in Pasadena, Calif., said Tuesday. Opportunity is headed south toward "Solander Point" after leaving the southern tip of "Cape York" six weeks ago, the lab said. Both sites on the western rim of the 14-mile-wide Endeavour Crater offer access to older geological deposits than the rover visited during its first seven years on Mars, NASA scientists said. On its journey Opportunity is crossing a flatter area dubbed Botany Bay scientist say is well-suited for rover driving. "The surface that Opportunity is driving across in Botany Bay is polygonally fractured outcrop that is remarkably good for driving," Brad Joliff, Opportunity science team member at Washington University in St. Louis, said. "The plates of outcrop, like a tiled mosaic pavement, have a thin covering of soil, not enough to form the wind-blown ripples we've had to deal with during some other long treks." The Solander Point destination offers both a tall cross section of rock layers for examination and also an expanse of terrain with a north-facing slope, favorable for the solar-powered rover to stay active and mobile through the coming martian Southern Hemisphere's winter, the lab said.