The sodium cloud

The sodium cloud

. Ios neutral sodium cloud (left) as seen from the Earth, shown together with Jupiter (center) and a schematic drawing of Ios orbit to scale. Excited sodium atoms that come from Io (location denoted by a cross) emit radiation at spectral lines that can be detected from ground-based optical telescopes. These observations of the sodium cloud were made with the 0.61-meter (24-inch) telescope at Table Mountain Observatory in California; the image of Jupiter was taken at a different time and place. (Courtesy of Bruce Goldberg and Glenn Garneau, Jet Propulsion Laboratory.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University