US, Europe look to partnership on Mars exploration

For almost half a century, the United States has dominated the exploration of Mars from the first grainy black-and-white pictures of the craggy surface to the more recent discovery of ice.

Now, budget woes are pushing NASA toward a joint exploration venture with Europe. By 2016, the U.S. may unite with the European Space Agency for future Mars trips — a move that would mark a significant shift for NASA.