A possible trace carbon dioxide polar cap on Iapetus

Eric E. Palmer, Robert H. Brown

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

We model ballistic transport of CO2 on the surface of Iapetus, accounting for gravitational binding energy and polar cold traps. We find that if CO2 is in the form of ice, it has a long enough residence time to be spectroscopically detected. We determine that at midlatitudes, CO2 is volatile, will rapidly ablate, and be sequestered in a polar cold trap. In addition, we find that due to the inclination of Iapetus's orbit, the poles provide only a temporary cold trap, requiring the CO2 to move to the opposite pole at the end of the winter season. During each transit, 5% of the CO2 will reach escape velocity and be lost from the system. Finally, we make a prediction of the latitudinal extent and thickness of a possible CO2 polar cap that could be detected during Cassini's 2007 September flyby of Iapetus.

Original languageEnglish (US)
Pages (from-to)L125-L128
JournalAstrophysical Journal
Volume666
Issue number2 PART 2
DOIs
StatePublished - Jan 1 2007

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Keywords

  • Individual (Iapetus)
  • Planets and satellites

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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