Some of the science results of the EPOXI flyby of Hartley 2 are just starting to come out …
Primordial dry ice fuels comet jets.
Of great interest is the comment by Jessica Sunshine[/URL] (deputy principal investigator for the EPOXI mission):
Quote:
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"We now have unambiguous evidence that solar heating of subsurface frozen carbon dioxide (dry ice), directly to a gas, a process known as sublimation, is powering the many jets of material coming from the comet. This is a finding that only could have been made by traveling to a comet, because ground based telescopes can't detect CO2 and current space telescopes aren't tuned to look for this gas," Sunshine said.
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That's big news to me ! Does this also mean that
no accurate, (or unambiguous), ground-based measurements for sublimating CO2 exist for any given solar system object??
(I may be reading too much into this statement but is a fairly assertive one ..?..)
Jessica Sunshine is no slouch in spectroscopy ..
Quote:
Jessica is an expert in analyzing spectra to remotely infer the composition of asteroids, meteorites, the moon and Mars..
Jessica is a Principal Investigator in NASA's Planetary Geology and Geophysics Program researching the composition of asteroids and meteorites.
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Hmm makes me wonder even more about Earth-based measurements concerning the proportions of frozen CO2/H2O on Mars' poles …
Still, it also helps to clarify some lingering questions about the likely composition of comets and their jets.
Cheers