Geotimes Home | AGI Home | Information Services | Geoscience Education | Public Policy | Programs | Publications | Careers
Last December, the NASA spacecrafts Galileo and Cassini snapped pictures
of a new and enormous volcanic plume near the pole of Io, one of Jupiter's
moons (see Geotimes,
December 2000). The Galileo camera spied a bright lake of lava at the
site, and the Cassini camera, using an ultraviolet filter, was able to
detect a plume of erupting gaseous material reaching nearly 400 kilometers
above the surface.
During an Aug. 5 flyby, Galileo captured a
series of six pictures of Tvashtar Catena, the volcanic feature from which
the plume originated. So far there is no direct evidence that the site
is still active, but if the formation is experiencing any lava flows or
eruptions, scientists will hopefully see it when they review Galileo footage
this week and will have acquired the closest look yet at active volcanism
on Io, understood to be the most geologically active body in the solar
system.
Galileo also took pictures of Tvashtar from greater
range. These more distant, wider angle views of the area provide context,
with a resolution of about 52 meters (170 feet). Once the Galileo data
have been analyzed, scientists hope to learn more about the composition
of Tvashtar-region surface materials, and, if the plume is indeed active,
the composition of plume gasses.
Emily D. Johnson
Visit the Jet Propulsion Laboratory Web site for more: www.jpl.nasa.gov/galileo/news/thiswk.html.
|
Geotimes Home | AGI Home | Information Services | Geoscience Education | Public Policy | Programs | Publications | Careers |