Saturday, March 03, 2007
SPECTACULAR NEW IMAGES FROM SATURN
There are some spectacular new images (click on a picture for the high resolution image), and a time lapse movie, taken of Saturn by the Cassini spacecraft. All images and captions are from NASA.
The giant planet is a moody world
The giant planet is a moody world whose disposition appears to change with the view. Its atmosphere rages with thunderous and hurricane-like storms. Its majestic rings spin a tale of ancient collisions and cataclysm. And its moons may hold secrets to the origins of life.
This view looks toward the lit side of the rings from about 28 degrees below the ring plane. The image was taken using a spectral filter sensitive to wavelengths of infrared light centered at 890 nanometers. The view was acquired with the Cassini spacecraft wide-angle camera on Jan. 30, 2007, at a distance of approximately 1.1 million kilometers (700,000 miles) from Saturn.
Image scale is 60 kilometers (38 miles) per pixel.
Saturn's shadow stretches completely across the rings in this view, below, taken on Jan. 19, 2007.
Surely one of the most gorgeous sights the solar system has to offer, Saturn sits enveloped by the full splendor of its stately rings.
Taking in the rings in their entirety was the focus of this particular imaging sequence. Therefore, the camera exposure times were just right to capture the dark-side of its rings, but longer than that required to properly expose the globe of sunlit Saturn. Consequently, the sunlit half of the planet is overexposed. Between the blinding light of day and the dark of night, there is a strip of twilight on the globe where colorful details in the atmosphere can be seen. Bright clouds dot the bluish-grey northern polar region here. In the south, the planet's night side glows golden in reflected light from the rings' sunlit face.
The view is a mosaic of 36 images -- that is, 12 separate sets of red, green and blue images -- taken over the course of about 2.5 hours, as Cassini scanned across the entire main ring system. This view looks toward the unlit side of the rings from about 40 degrees above the ring plane. The images in this natural-color view were obtained with the Cassini spacecraft wide-angle camera at a distance of approximately 1.23 million kilometers (764,000 miles) from Saturn.
Image scale is 70 kilometers (44 miles) per pixel.
Pictures from the Cassini spacecraft were assembled into this time-lapse movie, which shows what it looks like to pass through the rings of Saturn. Several moons of Saturn are shown orbiting the planet. The pictures were taken over a time span of 12 hours.
Here is NASA's description of the movie:
"This life-like movie sequence captures Saturn's rings during a ring plane crossing--which Cassini makes twice per orbit--from the spacecraft's point of view.
The movie begins with a view of the sunlit side of the rings. As the spacecraft speeds from south to north, the rings appear to tilt downward and collapse to a thin plane, and then open again to reveal the un-illuminated side of the ring plane, where sunlight filters through only dimly. The striking contrast between the sunlit and unlit sides of the ring plane can now be fully appreciated, thanks to the sense of continuity in time and space provided by this brief clip.
The movie consists of 34 images taken over the course of 12 hours as Cassini pierced the ring plane. Additional frames were inserted between the original images in order to smooth the motion in the sequence -- a scheme called interpolation.
Six moons careen through the field of view during the sequence. The first large one is Enceladus, whose slanted motion from the upper left to center right nicely illustrates the inclination of its orbit with respect to the rings. The second large one, seen in the second half of the movie, is Mimas, going from right to left.
This movie begins with a view looking toward the lit side of the rings from about 9 degrees below the ring plane. It ends when the spacecraft is 8 degrees above the ring plane. The clear-filter images in this movie sequence were taken with the Cassini spacecraft wide-angle camera on Jan. 17, 2007, at a distance of approximately 900,000 kilometers (500,000 miles) from Saturn.
Image scale is 48 kilometers (30 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. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The Cassini imaging team homepage is at http://ciclops.org