It is no Great Red Spot, but these two side-by-side views show the longest-lived electrical storm yet observed on Saturn by NASA's Cassini spacecraft.
The views were acquired more than three months after the storm was first detected from its lightning-produced radio discharges on Nov. 27, 2007. See Hissing Storm for an earlier color view of this storm. Cassini imaging scientists believe the storm to be a vertically extended disturbance that penetrates from Saturn's lower to upper troposphere.
The view at left was created by combining images taken using red, green and blue spectral filters, and shows Saturn in colors that approximate what the human eye would see. The storm stands out with greater clarity in the sharpened, enhanced color view at right. This view combines images taken in infrared, green and violet light at 939, 567 and 420 nanometers respectively and represents an expansion of the wavelength region of the electromagnetic spectrum visible to human eyes. This view looks toward the un-illuminated side of the rings from about 3 degrees above the ringplane. Janus (181 kilometers, or 113 miles across) appears as a dark speck just beneath the rings in both images.
These images were obtained with the Cassini spacecraft wide-angle camera on March 4, 2008, at a distance of approximately 1.3 million kilometers (800,000 miles) from Saturn. Image scale is 74 kilometers (46 miles) per pixel.
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 mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. The radio and plasma wave science team is based at the University of Iowa, Iowa City.
For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . The radio and plasma wave science instrument team home page is at: http://www-pw.physics.uiowa.edu/plasma-wave/cassini/home.html.
Credit: NASA/JPL/Space Science Institute