spacetoday.net: Rosetta comet has double nucleus

Posted: Fri, Jul 18, 2014, 8:38 AM ET (1238 GMT)
Comet Churyumov-Gerasimenko nucleus seen by Rosetta, July 2014 (ESA et al.)

The comet that is the target of a European mission appears to have a nucleus comprised of two bodies, not one, which could complicate plans to land a spacecraft on the comet. Images released this week from ESA's Rosetta spacecraft show that the nucleus of comet 67P/Churyumov-Gerasimenko appears to be a contact binary: two distinct bodies touching each other, vaguely resembling a rubber duck. How the nucleus got that shape isn't clear yet to planetary scientists. The comet is the destination of Rosetta, launched by ESA in 2004 on a convoluted trajectory that required three Earth gravity assists and one Mars gravity assist to reach the comet. Rosetta will rendezvous with the comet next month, and is planned to deploy a small lander, Philae, to the surface of the nucleus in November. The nucleus's unusual shape could make that landing more difficult.