News: Sciencedaily 4-5-2011
For the first time, scientists have found convincing evidence for the presence of liquid water in a comet, shattering the current paradigm that comets never get warm enough to melt the ice that makes up the bulk of their material.
http://www.sciencedaily.com/releases/2011/04/110405175018.htm
"Current thinking suggests that it is impossible to form liquid water inside of a comet," said Dante Lauretta, an associate professor of cosmochemistry and planet formation at the UA's Lunar and Planetary Laboratory.
Breaking news: 18 november 2010,:
http://www.youtube.com/watch?v=SRwO0j5_sRo
Mind also the "smooth waist" of the dumbbell shaped icy mass with two distinct spots of concentrated jets.
See also: Sciencedaily
"Deep Impact Spacecraft Successfully Flies by Comet Hartley 2"