Gallery of Curiosity Rover's 'UFO' Photos

 When the Curiosity rover beamed back its first batch of photos, a hazy, distant object mysteriously appeared and then disappeared in consecutive images of the Martian horizon. Cries of alien activity echoed across the Internet and even NASA scientists were perplexed at first. They eventually decided the hazy object was the plume of dust kicked up by the sky crane that delivered the rover close to the Martian surface, then veered off and struck the ground some 2,000 feet (600 meters) away.