Take a long, hard look at the picture below:

(Source: NASA.gov photos)

Image source: NASA via the Houston Chronicle

Do you see the bright object in the background? How about now using a close-up?

(Source: NASA.gov photos)

Image source: NASA via the Houston Chronicle

That is apparently a mysterious light captured by the Mars rover Curiosity last week. So far, the light has no official explanation. NASA hasn’t even claimed the photo. In fact, it’s not even known if the photo is legit, although it is spreading across the Internet.

But that hasn’t stopped some from speculating. The Houston Chronicle has some of the theories:

Although the space agency hasn’t issued any official statement yet about the phenomenon, bloggers and NASA enthusiasts have started chiming in.

Scott C. Waring, who maintains the website UFO Sightings Daily, posted the photo April 6.

Waring noted that the light shines upward, as if from the ground, and is very flat across the bottom.

“This could indicate there there is intelligent life below the ground and uses light as we do,” Waring wrote on his website. “This is not a glare from the sun, nor is it an artifact of the photo process.”

Still, there is one plausible explanation that comes from a commenter on the site Reddit: an electrified dust devil. One person linked to a story from 2005 that appears to show something similar captured by the other Mars rover, Spirit:

(Source: Mars rover Spirit via Thunderbolts.info)

Image source: Mars rover Spirit via Thunderbolts.info

“These martian dust devils dwarf the five-to-10 meter terrestrial ones, can be greater than 500 meters in diameter and several thousand meters high. The track patterns are known to change from season to season, so these huge dust pipes must be a large factor in transporting dust and could be responsible for eroding landforms,” Dr. Peter Smith of the University of Arizona said in a NASA press release in 2004.

A call to NASA was not immediately returned. If it ends up being anything else, we’ll let you know.