spacetoday.net: Deep Impact comet surprisingly fluffy

Posted: Wed, Sep 7, 2005, 9:21 PM ET (0121 GMT)
Tempel 1 comet after Deep Impact collision (NASA/JPL)

Scientists analyzing data from NASA's Deep Impact mission said this week that the comet the Deep Impact probe collided with had an unexpectedly weak structure. Planetary scientists, discussing the results from the mission at a conference in England, said that the nucleus of comet Tempel 1 has a fluffy structure that is weaker than a bank of powder snow. That porous structure would allow the outer layers of the nucleus to very quickly heat up and cool down, potentially preserving the inner portions of the comet in a pristine state since the comet's formation early in the solar system's history. The plume of materials ejected by the comet by the impact of the Deep Impact probe also had a high amount of organic molecules, which confirms speculation by some scientists that comets may be a key source of the organic material needed for life to develop on terrestrial worlds like the Earth.