'Hut' on the moon is the latest imagined alien artifact

China's Yutu-2 rover, which landed on the far side of the moon in 2019, has spotted a rectangular object on the lunar horizon. The phrase used for it by a Chinese government web site, according to the website Space.com, translates as "mystery hut," which has fuelled predictable speculation about what the object really is. It's most likely a boulder, of course, but the speculation is the latest in a long line of episodes in which imaginative people believe they see alien artifacts on objects in space or on other worlds.

There have been lots of suggestions about what the hut could be, and wags on the web have suggested it's everything from a lost Amazon delivery box to an astronaut outhouse to a Borg cube from the Star Trek series to the monolith from the movie 2001 A Space Odyssey.

But of course it's most likely just a large rock with a rectangular side facing the camera. We'll know for sure at some point, as Yutu-2 is now reportedly heading toward the object to investigate. The rover is not quite a speed demon, though, so it'll take a couple of months to get there.

Whenever new images come back from robots exploring the solar system, those who yearn to see signs of alien life pick out shapes and shadows that may look like animals or structures that could be signs of past civilizations. None of these claims have stood up to further scrutiny. But among the scientists who actually run these missions, the tradition continues.

American astronomer Percival Lowell founded the famous and still operating Lowell observatory in Flagstaff Arizona in 1894 and used it to look for what he believed were  canals criss-crossing the surface of Mars. Lowell imagined these mega-projects could be the result of a Martian civilization desperate for water on a desert planet. This idea of alien engineers led to a plethora of science fiction about Martians, including H.G. Wells's famous novel The War of the Worlds.

Spacecraft that have since been sent to Mars have failed to spot any such canals, but that hasn't stopped others from finding other features on the Red Planet that seem to indicate signs of alien life. 

One of the most famous is the "face" on Mars, a low resolution image of a hill taken in 1976 by the Viking orbiter. Shadows cast across the undulating surface made it look like a giant sculpture in the form of a head looking straight up to the heavens.  

Years later another orbiter equipped with a higher resolution camera revealed that the face is actually just a hill and not an ancient Martian monument. But that hasn't prevented conspiracy-minded people such as Richard Hoagland from claiming that the structure is artificial, part of a city that includes pyramid structures nearby. He, of course, also claims that NASA is covering up any signs of alien life.

Other people examined photos of rocks taken by Mars rovers and spotted a squirrel or rat, a figure of a woman and an assortment of other — well, interesting-looking rocks.

The phenomenon of seeing familiar shapes in objects is called pareidolia, in which the brain fills in missing information to make a familiar shape.

We've all had fun with that on summer days lying in the grass and watching the clouds which are full of faces, animals and all kinds of imaginary shapes. It's likely a cognitive artifact of our remarkable pattern recognition abilities, which gives us the ability to identify faces, for example. 

The discovery of alien life, when or if it happens, will answer one of the fundamental questions in science: are we alone in the universe? So far, the best telescopes and spacecraft have not been able to answer that question...yet. In the meantime, we have fuzzy images and optical illusions to fire our imaginations. 

But on the other hand, wouldn't it be interesting if Yutu-2 reaches that hut on the moon and finds a door?  Highly unlikely, but fun to think about.