The tiny robot spacecraft "Philae" has landed on a comet - the first time that's ever been done by an Earth-launched craft.

The congratulatory messages were in several languages as the European Space Agency celebrated the accomplishment at about 9 a.m. Mountain Time.

The lander was jettisoned from a larger spacecraft called Rosetta, which made a 10 year trip (including some time in hibernation) of 4 billion miles to get into orbit around the comet.

The comet is Comet 67P/Churyumov-Gerasimenko (named after who discovered it) and is on its approach around the Sun before heading back out into the solar system. It's about 2 and half miles in size and is shaped like a peanut or maybe a rubber duck, depending on who you talk to.

There are some questions about the landing, though. Philae was supposed to anchor itself to the comet with "harpoons." That didn't happen. With the low gravity, the lander bounced at least once.

Lander project manager Stephan Ulamec thinks everything is fine, saying, "Maybe we didn't just land once, we landed twice." More analysis is being done.