Japan hopes sunlight can save stricken Slim Moon lander

Before shutdown, mission control was able to successfully gather details of Slim's predicament, as well as images and data about its descent to the lunar surface.

"We're relieved and beginning to get excited after confirming a lot of data has been obtained," Jaxa said.

The agency promised updates through the week.

Moon missions try to land early in the "lunar day", when the Sun comes up over the eastern horizon. This gives a spacecraft about two "Earth weeks" of illumination before the Sun then sets in the west for two weeks of darkness.

It's currently "morning" at Slim's landing location on the slopes of Shioli Crater. If, as suspected, the spacecraft's solar cells are pointing westward, then it may have to wait until the "lunar afternoon" before those cells catch enough light to start charging the battery system.

Slim was carrying two small rovers, which data indicates it managed to eject as planned just before touchdown.

The craft is also equipped with an infrared camera to study the local geology. How much it could investigate if power levels are restored is uncertain.

Statistically, it's proven very hard to land on the Moon. Only about half of all attempts have succeeded.

Prior to Slim's touchdown only the US, the former Soviet Union, China and India had made it to the surface intact.

A private American mission gave up its landing bid earlier this month when it suffered a propulsion fault shortly after launch from Earth. Another commercial US mission will try its luck in late February.