A new image taken by NASA's Curiosity rover appears to be a mysterious spec of light on the Martian horizon, but others believe it could just be a dead pixel in the photo.

According to NBC News, the official explanation is a dropout pixel, but the image has sparked debate among several blogs and websites claiming it could be an alien light source. UFOSightingsDaily.com posted the photo, including an explanation for why it is not a photographic imperfection.

"An artificial light source was seen this week in this NASA photo which shows light shining upward from... the ground," wrote Scott C. Waring. "This could indicate there there is intelligent life below the ground and uses light as we do. This is not a glare from the sun, nor is it an artifact of the photo process. Look closely at the bottom of the light. It has a very flat surface giving us 100% indiction it is from the surface. Sure NASA could go and investigate it, but hey, they are not on Mars to discovery life, but there to stall its discovery."

Curiosity took the photo on April 3 with its right-hand navigation camera (navcam). A stereo system, the left-hand navcam does not capture the light spec, indicating the photo taken by its counterpart probably had a photographic imperfection.

An official from NASA's Jet Propulsion Laboratory (JPL) offered a different explanation.

"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," Justin Maki, lead for Curiosity's engineering cameras, told Fox News. "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."

The Houston Chronicle reported Curiosity arrived at a location on Mars known as "the Kimberley." The spot is of interest to NASA because it may contain ancient rocks that could provide clues to Mars' environmental history and maybe a time where life existed on the planet.

The Kimberley is similar to Curiosity's main destination of Mount Sharp, in that they both likely hold clues to Mars' environmental history.