Life on Mars? How about light on Mars? Actually, how about neither?
NASA's Curiosity rover snapped an image of what appears to be a bright white light shining on the planet's horizon. The speculation surrounding the photo was covered by many outlets, including NBC News and the Houston Chronicle.
So what is it? Is it a UFO? It's a UFO, right? Come on, say it's a UFO, will ya?
Well, no. Yahoo News asked NASA's Jet Propulsion Laboratory what was up. In an email, Justin Maki, an imaging scientist there and the lead for the Curiosity's engineering cameras, explained that the "bright spots" appear in images taken by the stereo camera's right-eye camera, but not the left.
"In the two right-eye images, the spot is in different locations of the image frame and, in both cases, at the ground surface level in front of a crater rim on the horizon."
"One possibility is that the light is the glint from a rock surface reflecting the sun. When these images were taken each day, the sun was in the same direction as the bright spot, west-northwest from the rover, and relatively low in the sky. The rover science team is also looking at the possibility that the bright spots could be sunlight reaching the camera's CCD directly through a vent hole in the camera housing, which has happened previously on other cameras on Curiosity and other Mars rovers when the geometry of the incoming sunlight relative to the camera is precisely aligned. We think it's either a vent-hole light leak or a glinty rock."
Doug Ellison, who also works at NASA's Jet Propulsion Laboratory, offered his opinion on Twitter. His theory: a "cosmic ray hit."
Phil Plait of Slate's Bad Astronomer blog agrees with Ellison. He explains that cosmic rays "are charged subatomic particles (like protons, electrons and so on) zipping around in space." They don't show up on Earth as our atmosphere absorbs them, but "if you put a telescope in space, they are bombarded by these little beasties."
Bottom line — experts aren't sure what the "light" is yet. But we can be confident it isn't E.T.
Follow Mike Krumboltz on Twitter (@mikekrumboltz).