After 4 Billion Mile Trip, Just a Half Marathon to go for Philae as it Tries to Make First Ever Soft Landing on a Comet

The rugged surface of Comet 67P/Churyumov–Gerasimenko, as seen by the orbiting Rosetta spacecraft. (Source: European Space Agency - ESA) At 9:03 GMT tomorrow, or 4:03 a.m. Eastern time in the United States, the final stage in an historic 10-year adventure is set to begin: The Rosetta spacecraft will attempt to drop a refrigerator-sized lander onto the rough and rocky surface of a comet. For the Philae lander, which has been safely secured to Rosetta during the long trip to Comet 67P/Churyumov–Gerasimenko, that last leg of the journey will be only 13.67 miles. That's a little more than a half marathon — after a 4 billion mile trip. If Philae is successful, it will be the first ever soft-landing on a comet. There is much that can go wrong. As Alan Stern of the Southwest Research Institute put in a story in the Boulder Daily Camera, "I think the challenges are ...