The two working science experiments on Mars, solar-powered robots called Spirit and Opportunity, have been “hunkered down” for the last six weeks waiting for dust storms to blow over. The storms have blown over but the air is still dusty. However, each of the rovers gathered enough power to move a little and prove that they are still in working order. Opportunity rolled about 13 metres closer to Victoria Crater. Spirit backed away from the Gusev Crater on the other side of the planet.