China just sent a secret mini-rover to the far side of the moon on its Chang'e 6 sample-return probe

China's latest lunar mission is carrying a secret rover to the moon's far side, new photos reveal. Eagle-eyed observers spotted the mysterious spacecraft strapped to the side of a lander that is scheduled to touch down on the moon next month — but the roaming robot's purpose remains unknown.

On Friday (May 3), the China Academy of Space Technology (CAST) successfully launched an autonomous Long March 5 rocket into space. This was the first step in the country's Chang'e 6 mission, which aims to be the first-ever mission to collect samples from the moon's hidden far side and carry them to Earth. 

The main payload of the moon-bound rocket is a lunar lander that is expected to touch down on Earth's largest satellite at some point in early June. There, the spacecraft will collect samples from the surface and then launch them back to Earth in a return module — similar to the Chang'e 5 mission, which landed a spacecraft on the moon in 2020 and successfully returned lunar samples to Earth several months later.

Video: Watch China's Chang'e 6 probe launch to the moon on a Long March 5

Little else was known about the Chang'e 6 mission before launch, other than that it would also carry undisclosed payloads from France, Sweden, Italy and Pakistan to the moon, SpaceNews reported. 

However, following the successful launch, CAST released new photos of the lander, and people quickly noticed a small gray object with wheels strapped to the lander's side. 

"Yeah, okay. That looks like a previously undisclosed mini rover on the side of the Chang'e-6 lander," journalist Andrew Jones, who closely follows China's space program, wrote in a post on the social platform X.

The suspected rover's primary task on the moon remains unclear. However, a subsequent translated statement from the Shanghai Institute of Ceramics, which provided several components for the Chang'e 6 mission, revealed that it has an infrared imaging spectrometer although its purpose is unclear. Due to the size of the robot and the conditions it will face on the moon, its mission will likely be short, SpaceNews reported.

CAST already has the Yutu-2 rover on the far side of the moon, which landed in 2019 as part of the Chang'e 4 mission — the first mission to successfully land a spacecraft on the far side of the moon. Yutu-2 has already made some big finds, including the discovery of small glass spheres on the lunar surface. 

This is not the first time that China has surprised the world with undisclosed payloads. During the country's Tianwen-1 mission to Mars in 2021, several spacecraft, including a Mars orbiter and the Zhurong Mars rover, released secret mini-cameras to take selfies on or around the Red Planet, SpaceNews reported. 

In the past, CAST has also been secretive about other operations including the demise of the Zhurong Mars rover and an incident in 2022 when a Chinese rocket carrying an undisclosed object crashed into the moon's surface.

CAST's ultimate goal is to put humans on the moon by 2030, and the agency will start to test-launch a new type of large reusable rocket next year. However, like with the new rover, the details of this mission are being kept closely under wraps.