Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

October 3, 1996
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Three Views of Jupiter's Io
The Galileo Project, JPL, NASA

Explanation: The Galileo spacecraft orbiting Jupiter continues to return impressive results. The Galileo team has just released three more photographs of Jupiter's volcanic moon Io taken in June. These three photos are reflected at the bottom of the above picture, digitally enhanced to better show important features. Some areas of Io, it now appears, are truly red, not the usual green and yellow hues recorded previously. In fact, the last major mission - Voyager - did not have cameras sensitive to red light. This red material appears to be associated with recent volcanic eruptions, and the red color appears to fade with time. Comparisons of these photos with 17-year old Voyager photos show that about a dozen surface regions -- each the size of Connecticut-- have been affected by Io's active volcanoes.

Tomorrow's picture: Globular Cluster Omega Centauri

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA).
NASA Technical Rep.: Sherri Calvo. Specific rights apply.
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