Moment of truth in Europe's ten-year mission to explore a comet

(Reuters) - European scientists launched a probe from spaceship Rosetta on Wednesday in an historic attempt to examine the surface of a comet, starting a seven-hour descent that marks the most nail-biting phase of a ten-year mission.

Overcoming technical glitches, the European Space Agency craft jettisoned its lander on schedule at around 0400 ET to collect samples from the surface of 67P/Churyumov-Gerasimenko, which it has been orbiting since August.

"Now it's up to gravity to bring it down," Stefan Ulamec, Lander Manager from German Aerospace Center DLR, said.

The material that the lander, named Philae, analyses in the first contact of its kind will give insight into how Earth and other planets formed.

Comets are remnants of the formation of the 4.6-billion-year-old solar system. Scientists believe they may have brought much of the water in today's oceans.