robot spacecraft Galileo to take hourly pictures of this moon of Jupiter prior to its most recent encounter. The most obvious changes in Io are due to the changing amount of sunlight reflected from the moon to the spacecraft. More careful inspection does verify continuous volcanic plumes. The most prominent plume visible is from Prometheus, visible just below Io's equator. This plume was first photographed in 1979 by Voyager, so Prometheus appears to have been erupting continuously for at least 18 years! On most browsers, the above picture will appear animated. To stop the movie, click on your broswer's "stop" button.
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture Of the Day
Publications with keywords: Io
Publications with words: Io