The Mars Curiosity Rover sent these photos back to NASA. NASA released this statement

"In the thousands of images we've received from Curiosity, we see ones with bright spots nearly every week," said Justin Maki of NASA's Jet Propulsion Laboratory, Pasadena, Calif., leader of the team that built and operates the Navigation Camera. "These can be caused by cosmic-ray hits or sunlight glinting from rock surfaces, as the most likely explanations."