Slow Northern Reveal
January 30, 2009
Cassini imaging scientists have waited years for the sun to reveal the hexagonal wave pattern in the clouds of Saturn's north pole, part of which can be seen at the top of this image from the Cassini spacecraft.
This mosaic combines four separate near-infrared images to show one full side of the hexagon and two partial sides cut off by shadow.
When the spacecraft arrived in 2004, winter darkened the north pole. As the planet continues its 29-year orbit, the sun sheds more light on northern features and uncovers more of this strange, long-lived formation first observed in Voyager images of the illuminated northern pole from the early 1980's.
False color images made from data collected by Cassini's visual and infrared mapping spectrometer (VIMS) have previously captured the full six-sided pattern in the infrared. (See Saturn's Active North Pole.)
South of the hexagon at least five large storm systems can be seen spinning in a sea of smaller storms.
The image was taken with the Cassini spacecraft wide-angle camera on Dec. 1, 2008 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 712,000 kilometers (442,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 69 degrees. Image scale is 39 kilometers (24 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.
Credit: NASA/JPL/Space Science Institute