Yesterday the European Space Agency made history by completing the first soft landing on a comet. The Rosetta mission successfully dropped the lander Philae onto Comet 67P/Churyumov-Gerasimenko, and it has already sent back data and photos.
But the landing was not as soft as scientists were expecting: After the failure of Philae's thrusters and harpoons, which would have anchored the lander to the surface, the lander seems to have bounced to a height of about half a mile. After a second, smaller bounce, it settled down on an unknown site likely half a mile away from its intended target. This region is a jagged landscape near what appears to be a steep cliff.
Because of the shadow from the cliff, the lander is only getting a few hours of sunlight per day. That's a problem, since it's 60-hour battery needs to recharge via solar panels.
One of Philae's feet is not touching the surface of the comet, and the other two have not screwed in. This means the lander is not anchored, and probably will not be able to drill into the comet's soil without causing damage to the probe. If mission control tries to deploy the harpoon anchors now, it might send the lander flying into space again.