BERLIN — The European Space Agency says it has lost contact with its Rosetta probe after it hit the surface of a comet, marking the planned end of a 12-year mission.

Scientists sent the probe on a collision course with comet 67P/Churyumov-Gerasimenko, where Rosetta will now rest with its sidekick Philae, which landed on the surface in November 2014.

The loss of contact was meant to happen as soon as Rosetta detected a “problem” — i.e., the impact.