For the past few months an ESA probe named Rosetta has been orbiting Comet 67P/Churyumov–Gerasimenko. The comet is consists of two lobes connected by a narrow dusty neck. It’s about 6km from end to end. Now a small lander named Philae that has been carried by Rosetta is set to embark on a mission to land on Comet Churyumov–Gerasimenko’s smaller lobe.
Philae will be released from Rosetta at a distance of 22.5km from the comet. The proposed landing site is about 1 square kilometre in size and is located in the smooth area near the top of the image. This location was determined as being the safest location for a landing.
On touchdown the lander will fire special harpoons into the surface to hold on, as the gravity of the comet is so weak it could otherwise bounce off.
More information can be found on Philae’s upcoming landing in this ESA press release.