Mars rover Curiosity found rocks on the Martian surface that are too big to be carried by wind, so researchers suppose water must have existed on Mars at one time. Over the next two years, Curiosity will continue its search for signs of ancient microbial life on Mars.
On Thursday, NASA's Mars Curiosity rover identified what are believed to be rocks moved by water that once flowed on the Red Planet. Curiosity's further exploration is hoped to determine whether Mars was once inhabited by microorganisms.
National Plug In Day celebrated the electric car in 60 cities over the weekend. Declared all but dead a short while ago, the electric car market is beginning to thrive. But can electric cars ever gain a meaningful foothold in the gas-dependent US auto industry?
More than 100 victims of the drug war went to Washington as part of Mexico's Caravan for Peace to demand justice for their families. The group is pressing both governments to rethink a policy that has cost so many lives.
The space shuttle Endeavour landed in California on its way to its final resting place. On the way, it made a flyover in Tucson, Arizona where former Congresswoman Gabrielle Giffords and her husband Mark Kelly, Endeavour's retired commander, were watching.
Endeavour landed in Houston while riding piggyback atop a modified Boeing 747 jumbo jet to end the first leg of its three-day journey to Los Angeles, where the retired space shuttle will ultimately be transformed into a museum exhibit at the California Science Center.