BERLIN — 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 announced Thursday that the probe will crash onto the comet Sept. 30 after a 5 billion-mile (8 billion-kilometer) odyssey. It will join its sidekick Philae, the lander that touched
