NASA’s Mars Curiosity rover has snapped thousands of pictures during the decade it has spent exploring the Martian surface, but a new image that appears to be a tantalizing open doorway on the red planet has understandably attracted special attention.
First things first: It’s not an otherworldly entrance into an alien temple. It gives us no pleasure to report that this apparent gateway to the Martian underworld is likely a small rock formation with a natural origin. NASA has not yet commented on this subtle detail in Curiosity’s picture, which was taken on May 7, though redditors speculated that it might be a natural stress fracture in a discussion of the image that has since been removed from the site (while also joking that is the space tomb of Jesus, E.T.’s crib, and a video game save point, among other hypotheses).
Curiosity is currently ascending Mount Sharp, a mountain that rises to an elevation of 18,000 feet from the floor of Gale Crater, where the rover landed in August 2012. The shot of the weird-looking opening was taken on a slope called Greenheugh Pediment, which is riddled with “gator-back” terrain, so named because it resembles reptilian scales. The rover has been carefully navigating this area for months in its quest to slowly climb this ancient Martian mountain, though it will likely never reach the summit.
The door-like formation is just the latest in a series of weird extraterrestrial features spotted over the decades by interplanetary explorers, robotic and human, that have sparked the imaginations of onlookers. Earlier this week, people marveled at new images of claw-like scratches that stretch for hundreds of miles across the western hemisphere of the red planet, which were captured from outer space by the European Space Agency’s Mars Express orbiter. These are not the markings of some giant Martian cat in search of a scratching post, but rather ancient fault lines.
And remember that “mystery hut” spotted by China’s Yutu-2 rover on the far side of the Moon? That turned out to be—drumroll—a rock. In fact, you can bet that just about any weird-looking object spotted by our robot friends on alien worlds is a rock. But here’s the secret: Rocks rock. They may not be quite as scintillating as the objects we may think they resemble—be they flowers, femurs, or floating spoons—but they contain stories about the solar system that date back for billions of years in some cases.
What’s more, NASA’s Perseverance rover, which landed on Mars in 2021, is currently collecting rock cores from an ancient dried-up lakebed that could become the first pristine samples of the red planet ever returned to Earth, if all goes to plan in the coming decade. Scientists think these rocks could potentially contain fossilized microbes that lived on Mars when it was habitable some four billion years ago. So while extraterrestrial formations shaped like doorways, huts, and flowers are fun to riff about, we may actually spot our first glimpse of alien life preserved in Martian rocks that may seem utterly humdrum at first glance.