China's first lunar rover, Yutu, has officially been declared lost.

The English-language website of the state-owned China News Service reported Wednesday that Yutu "could not be restored to full function Monday as expected and netizens mourned it on Weibo, China's Twitter-like service."

The six-wheeled, solar-powered moon buggy, whose name translates to "Jade Rabbit" in Chinese, hasn't been working since Jan. 25, when it experienced mechanical problems. The problems appeared to be related to the probe's process for shutting down for the lunar night, which lasts more than two weeks and brings the surface temperature down to –180 C.

The 140-kilogram rover arrived on the moon in December aboard the stationary Chang'e 3 lander, which became the first man-made vehicle to land on the moon in 37 years. It was designed to spend three months exploring for natural resources on the moon.

Chang'e 3 was named after a mythical Chinese goddess of the moon. It is designed to take scientific measurements for a year.