Nasa rover spots strange rock formation that looks like ‘alien doorway’ on Mars

Nasa’s Curiosity rover has captured a strange image of a rock formation on Mars that looks like a perfectly carved-out doorway on the Red Planet, sparking alien conspiracy theories.

While Nasa has not yet commented on the image taken by the rover’s Mast Camera (Mastcam), the weird rock formation might be the result of a natural stress fracture, likely from seismic activities.

Recordings made by Nasa’s Insight lander have shown that the Red Planet does experience tremors, with a recently-detected Marsquake found to be the biggest ever observed on the planet.

However, researchers are still working to determine how exactly quakes arise and propagate on Mars.

The door-like rock formation, spotted by Curiosity on the geological feature known as Greenheugh Pediment, may also have arisen from such tremors.

The rock formation was spotted as the rover was ascending Mount Sharp – which rises about 5.5km above the floor of Gale Crater, where Curiosity landed in August 2012.

As Curiosity was making its way through the terrain, mission engineers observed in March that the path ahead was carpeted with wind-sharpened hard sandstone rocks, which they said could increase wear on the rover’s wheels.

They plan to avoid such routes, nicknamed “gator-back” terrain after their scalelike appearance.

“It was obvious from Curiosity’s photos that this would not be good for our wheels. It would be slow going, and we wouldn’t have been able to implement rover-driving best practices,” Curiosity project manager Megan Lin of Nasa’s Jet Propulsion Laboratory in the US, said last month.

This is also not the first time such weird rock formations have been observed in the solar system.

Last year, China’s Yutu 2 rover spotted a strange cube-shaped formation on the moon that seemed unusually symmetrical with a flat top.

Researchers with CNSA’s outreach program Our Space joked that it might be an alien hut.

Then as the rover got closer to the structure earlier this year, new images revealed that the object is actually a small lumpy rock sitting on the edge of a crater.

The Yutu 2 team nicknamed the rock “jade rabbit” after its shape.

Many ascribe otherworldly explanations to such rock formations, but Michael Shermer, American historian of science and founding publisher of Skeptic magazine, calls this behaviour “patternicity”, or the tendency to find meaningful patterns in meaningless noise.