A door on Mars? The truth behind NASA’s baffling, viral photo

A mysterious photo of a door-like structure on Mars. (Image credit: @MarsCuriosity/Twitter)

NASA’s Mars rover Curiosity has captured a baffling image, which at the first glance looks like a tiny door.

The image, tweeted by the rover’s official account on May 19, ignited massive interest online, with many speculating that the “door” was a mysterious portal on the surface of the Red Planet.

But a series of follow-up photos released by NASA make it evident that the “door” is actually a crevice in a rock.

What looked like a door in a zoomed out photo is actually a crevice (encircled) on a massive rock.  (Image credit: mars.nasa.gov)

NASA said in a statement that its rover had been exploring a mound of rock called “East Cliffs” on May 7.

“The mound, on Mount Sharp, has a number of naturally occurring open fractures -- including one roughly 12 inches (30 centimeters) tall and 16 inches (40 centimeters) wide, similar in size to a dog door,” it said. “These kinds of open fractures are common in bedrock, both on Earth and on Mars.”

NASA explained why people viewing the image were seeing a door. “It’s a natural geologic feature! It may just *look* like a door because your mind is trying to make sense of the unknown. (This is called "pareidolia"),” it said.

NASA’s Curiosity is presently investigating a stretch of Mount Sharp. “(The region) may hold evidence of a major change from wetter to drier conditions in Mars’ early history,” it said.