Volcanic activity on lo at the time of the Ulysses encounter

John R. Spencer, Robert R. Howell, Beth E. Clark, David R. Klassen, Daniel O'Connor

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


The population of heavy ions in lo's torus is ultimately derived from lo volcanism. Ground-based infrared observations of lo between October 1991 and March 1992, contemporaneous with the 8 February 1992 Ulysses observations of the lo torus, show that volcanic thermal emission was at the low end of the normal range at all lo longitudes during this period. In particular, the dominant hot spot Loki was quiescent. Resolved images show that there were at least four hot spots on lo's Jupiter-facing hemisphere, including Loki and a long-lived spot on the leading hemisphere (Kanehekili), of comparable 3.5-micrometer brightness but higher temperature.

Original languageEnglish (US)
Pages (from-to)1507-1510
Number of pages4
Issue number5076
StatePublished - Sep 11 1992
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General


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