Caption
This color image of Jupiter is a composite made of 3 images taken by the narrow angle camera on October 4 from a distance of 81.3 million kilometers from the planet. It is composed of images taken in the blue, green, and red regions of the spectrum and is therefore close to the true color of Jupiter that one would see through an Earth-based telescope. The image is strikingly similar to those taken by the Voyager 1 and 2 spacecraft more than 21 years ago, illustrating the remarkable stability of Jupiter's weather patterns. The parallel dark and bright bands and many other large-scale features are quasi-permanent structures that survive despite the intense small-scale activity ongoing in the atmosphere. The longevity of the large-scale features is an intrinsic property of the atmospheric flows on a gaseous planet, like Jupiter, having no solid surface; but smaller features, like those in the dark bands to the north and south of the equator, are observed to form and disappear in a few days. Similar behavior was observed during the Voyager era.
Everything visible on the planet is a cloud. Unlike Earth, where only water condenses to form clouds, Jupiter has several cloud-forming substances in its atmosphere. The updrafts and downdrafts bring different mixtures of these substances up from below, leading to clouds of different colors. The bluish features just north of the equator are regions of reduced cloud cover, similar to the place where the Galileo atmospheric probe entered in 1995. They are called "hot spots" because the reduced cloud cover allows heat to escape from warmer, deeper levels in the atmosphere.
The Galilean satellite Europa is seen at the right, casting a shadow on the planet. It is this satellite which scientists believe holds promise of a liquid ocean beneath its surface.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.