The lander that made Japan the fifth nation to softly touch down on our closest celestial neighbor has produced one of its biggest surprises by waking up after a two-week lunar night.
The unmanned Smart Lander for Investigating Moon (SLIM) touched down last month at a wonky angle that left its solar panels facing the wrong way and without power. As the Sun’s angle shifted, however, SLIM returned to life for two days and carried out scientific observations of a crater with a high-spec camera before going to sleep again as darkness set in. Unsure whether the lander could withstand a harsh lunar night, JAXA had been cautious in its expectations that it would reawaken.
But SLIM surprised everyone by keeping its lights on after a night when temperatures dropped below -200 degrees Fahrenheit. The lander is now regenerating energy from sunlight to operate its instruments and is preparing to send a series of new images of the Moon’s surface to scientists back home.
Despite the power issues that have cut SLIM’s time on the Moon, Japan’s space agency remains confident it can revive the probe when conditions improve around mid-February when the Sun can supply it with energy. JAXA project manager Shinichiro Sakai said the lander had met its milestones during the descent to its historic landing on January 20, releasing a pair of small rovers to explore the surface.
Sakai said he was “absolutely delighted” by the first images sent back, almost identical to those he had seen in computer renderings. But he said why the solar cells aren’t working remains to be seen.
“We’re working with the best guess at what’s going on, but there’s still a lot we need to find out about the lander,” he said in a news conference. “We’re hoping we’ll be able to recharge the solar cells when the Moon is at its brightest.”
IFLScience notes that while SLIM’s power problems have cut its active time on the Moon short, it captured some fantastic pictures of the landscape and moonlit clouds after its initial hiatus. The lander’s next big challenge is to survive the Moon’s long, two-week lunar night, which can see temperatures plummet to as low as -200 degrees Fahrenheit.
SLIM may be able to turn itself on again once the Moon returns to sunlight, but it might not be able to generate enough energy to restart its science activities, JAXA says. The space agency is preparing a series of commands to send to the lander when conditions are right and will try to contact the probe as it recharges its batteries.