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Will JPL cause Deep Impact threat to Earth?

Posted: Sun Apr 17, 2005 10:25 am
by Robert Pitts
Impact of the space probe “Deep Impact” with Comet Tempel 1 is due to occur on July 4th 2005. Because the internal structure of a comet can only be guessed at - a "cratering" impact (from "Deep Impact") may cause extensive (possibly explosive) and prolonged venting of gases which, over time, might significantly alter the orbit of Comet Tempel 1. I am concerned that the full effects of such a venting event may not have been modelled by JPL? Could the proposed impact with the comet result in an altered orbit which ultimately puts Earth at risk?

Consider the quote below:
"In the world of science, this is the astronomical equivalent of a 767 airliner running into a mosquito," said Don Yeomans, a Deep Impact mission scientist at JPL. "It simply will not appreciably modify the comet's orbital path. Comet Tempel 1 poses no threat to the Earth now or in the foreseeable future," he added.
However, a mosquito’s body is soft and squashes upon impact. If it were solid (like Deep Impact) then it might do appreciably more damage to the 767. After all, this probe is meant to crater not simply splatter or bounce off.
I would also add that not too many people predicted that something as insignificant as foam insulation would pose any appreciable threat to the space shuttle!!! 8-o

Deep Impact link: http://deepimpact.jpl.nasa.gov