A European robot probe called Philae has made history by landing on a comet, the first spacecraft to ever achieve this the feat.
The Philae probe made a ten-year journey across the Solar System to reach the comet, which was speeding through space at more than 40,000 miles an hour.
But the landing didn't go quite to plan. It's thought Philae bounced back off the comet and landed on another part of it.
Now space scientists are working hard to stop the battery from running out.
What went wrong with the landing?
The solar-powered Philae probe is in the shadow of a cliff edge after bouncing almost a mile back into space and landing a kilometre away from where it should have.
European Space Agency experts say the historic probe has stabilised and begun to send its first pictures back from the surface of comet 67P.
But the bad landing has damaged the craft and its current location means the battery that powers it may not be able to recharge.
Here the BBC's space expert David Shukman explains to Newsround what went wrong with the landing.