from nbcnews.com: After a suspense-packed, seven-hour descent, the European Space Agency's Philae lander made an unprecedented touchdown on the surface of a comet Wednesday — marking the high point of a $1.3 billion, 10-year mission. Cheers erupted as the confirming signals were received at the European Space Operations Center in Darmstadt, Germany, at 11:03 a.m. ET. The signals took 28 minutes to travel at the speed of light over the 317 million miles (510 million kilometers) between Comet 67P/Churyumov-Gerasimenko and Earth. "It is sitting on the surface," reported Stefan Ulamec, Philae lander manager at the DLR German Aerospace Center. "Philae is talking to us — we are on the comet!"