John Spencer

Lowell Observatory

LONG-DISTANCE VOLCANOLOGY: EARTH-BASED STUDIES OF IO'S VOLCANISM

Jupiter's moon Io is one of the strangest and most fascinating objects
in the solar system, due to its intense volcanism which is powered
by tidal heating.  A combination of disk-resolved infrared imaging
and occultation photometry allows detailed studies of individual Io
volcanos from Mauna Kea and other ground-based observatories, with higher
time resolution than can be obtained from the Jupiter-orbiting Galileo
spacecraft.  The data provide evidence for frequent high-temperature
silicate volcanism in the form of lava lakes and "curtains of fire",
as well as spreading lava flows.  Temperatures are so high that exotic
lava compositions may be required.  I will also briefly discuss results
from the Hubble Space Telescope, which provides complementary information
on the effects of Io's volcanism on its surface, and allows direct
detection and characterization of volcanic plumes.