These two observations, each taken one hour apart, illustrate the winds around a white oval on Jupiter which is the result of the historic merger of two classic white ovals at 33 degrees south planetocentric latitude. Both the classic ovals and a pear-shaped region between them were visible in February 1997, but only one slightly larger oval was visible in September 1998. Ground-based observers confirmed that the two ovals had merged, but the event itself happened when Jupiter was behind the sun, out of sight from Earth in February 1998. The merger was an historic event, since the ovals formed in the late 1930's and have been observed continuously for 60 years. These images were taken through a near-infrared filter (756 nanometers)by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. This filter shows the features of Jupiter's main visible cloud deck. The oval is centered near 33 degrees south planetocentric latitude and 350 degrees west longitude and rotates in a clockwise sense about its center.
North is at the top of this mosaic. The smallest resolved features are tens of kilometers in size. The images of this new oval after the merger were taken were taken on September 25, 1998, at a range of about 1 million kilometers (620,000 miles).
The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC.
This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo Image Credit: NASA/JPL