A mysterious image from Mars is currently causing a stir online, and the world's richest man Elon Musk is getting involved.

The mission of NASA's Mars Global Surveyor space probe has been over for some time.

Between 1996 and 2006, the probe sent around 240,000 images back to Earth.

One image is now the subject of heated debate on social media, however.

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The photo, dated November 4, 2001, shows a vertical image section from a crater on the Red Planet in which a square-like formation can be seen.

The image can be viewed on the Arizona State University website.

Given the seemingly unnaturally right-angled arrangement, some alien theorists already suspect the walls of an ancient structure or a relic of extraterrestrial origin buried under desert sand.

The SpaceX founder also joined the discussion, responding to right-wing podcaster and fellow President Donald Trump ally Joe Rogan in a post on X on Saturday.

"We should send astronauts to Mars to investigate," Musk suggested.

However, it will probably be some time before humans set foot on Mars for the first time, so the discovery at latitude and longitude 28.088766°N/27.74899°E still leaves room for speculation.