After a journey lasting 12 years, a date has been set for the Rosetta spacecraft's final descent onto comet 67P/Churyumov-Gerasimenko.

The European Space Agency says the probe will crash onto the comet Sept. 30, joining its sidekick Philae. The lander touched down nearly two years ago.

The agency said Thursday that the final descent will require careful maneuvers and offer a unique opportunity to take close-up images of the comet before Rosetta hits the icy surface at about 1.8 kilometers per hour (1.12 mph).

Scientists decided to steer Rosetta onto 67P because the probe is unlikely to survive lengthy hibernation in orbit as the comet heads away from the sun.

Data from Rosetta and Philae have improved scientists' understanding of comets and the role they played in the early universe.