Mars dust storm clears, raising hope for stalled NASA rover

One of the biggest Martian dust storms on record is clearing up after nearly three months, raising hope that NASA's stranded, solar-powered robotic vehicle, Opportunity, will soon come back to life.The storm was first detected on May 30, and the US space agency's 15-year-old rover was last heard from on June 10, when it went into "sleep" mode as dust blocked out the Sun and darkness enveloped the Red Planet.