China's mysterious "Moon cube" is a mystery no longer. The big reveal: It's a rock that's not even shaped like a cube.

The nation's Yutu-2 rover discovered the object – which appeared to be a gray cube looming on the lunar horizon – in early December. The China National Space Administration (CNSA) dubbed it 'mysterious hut', playfully speculating that the cube might be an alien house or spacecraft.

News reports called it the 'Moon cube'.

The CNSA estimated the object was about 80 meters (262 feet) away, according to the blog 'Our Space', which is affiliated with the agency, and prepared to drive the rover toward it. The blog said it would take two or three months to reach the cube.

After several weeks of preparations and driving, the rover is close enough to see that the 'mysterious hut' is just a rock. Its sharp-lined geometric appearance on the horizon was a simple trick of perspective, light, and shadow.

In an updated posted on Friday, Our Space published the rover's latest photo of its target, below.

MoonRockMysteriousHutCloserYutu-2 image of the closer rock. (CNSA/CLEP/Our Space)

One of the rover's ground controllers noted in the blog that the rock is shaped like a rabbit, with smaller rocks in front of it that resemble a carrot. The rover's name, Yutu, means "Jade Rabbit" – which is now the name of the rock, too.

Yutu-2 reached the Moon in January 2019, when the Chang'e-4 lander touched down on the lunar surface and rolled out a ramp for the rover to descend. It was the first mission to land on the far side of the Moon.

In the three years since, Yutu-2 has driven over 1,000 meters (3,200 feet), used ground-penetrating radar to reveal a surprisingly deep layer of lunar soil, and identified rocks from the lunar mantle, below the crust, which were pushed to the surface when an asteroid crashed into the Moon billions of years ago.

A closer look at the rock. (CNSA/CLEP/Our Space)

The rover has survived long past its initial three-month mission, meaning Yutu-2 had plenty free time for a wild cube chase.

This article was originally published by Business Insider.

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