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Science 4 October 1985:
Vol. 230. no. 4721, pp. 63 - 65
DOI: 10.1126/science.230.4721.63
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Articles

Infrared Speckle Observations of Io: An Eruption in the Loki Region

R. R. HOWELL 1 and M. T. MCGINN 1

1 Institute for Astronomy, University of Hawaii, Honolulu 96822

Speckle observations of Jupiter's satellite Io at a wavelength of 5 micrometers during July 1984 resolved the disk and showed emission from a hot spot in the Loki region. The hot spot contributed a flux approximately equal to 60 percent of that from the disk. Images reconstructed by means of the Knox-Thompson algorithm showed the spot moving across the disk as the satellite rotated. It was located at 301° ± 6° west longitude, 10° ± 6° north latitude, and had a radiance of (2.96 ± 0.54) x 1022 ergs sec-1 cm-1 sr-1/A where A is the area of the spot. For an assumed temperature of 400 K, the area of the source would be 11,400 square kilometers. An active "lava lake" similar to that seen by Voyager may be the source of the infrared emission.

Submitted on April 1, 1985
Accepted on May 30, 1985


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Volcanic Activity on lo at the Time of the Ulysses Encounter.
J. R. Spencer, J. R. Spencer, R. R. Howell, B. E. Clark, D. R. Klassen, and D. O'Connor (1992)
Science 257, 1507-1510
   Abstract »    PDF »
Characterization of Io's Volcanic Activity by Infrared Polarimetry.
J. D. Goguen, J. D. GOGUEN, and W. M. SINTON (1985)
Science 230, 65-69
   Abstract »    PDF »


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