December 19, 2012
Cassini Spacecraft Captures Stunning Images From Saturn’s Shadow
April Flowers for redOrbit.com - Your Universe Online
Delivered just in time for the holiday season, another glorious, backlit image of the planet Saturn has arrived from NASA's Cassini spacecraft, which has been in orbit around the planet for more than eight years.
Cassini was deliberately positioned within Saturn's shadow during its 174th orbit around the gas giant on October 17, 2012. This positioning made for a perfect location from which to look in the direction of the Sun and take a backlit view of the rings and the dark side of the planet. Planetary scientists refer to the geometry of looking back towards the sun as "high solar phase," and the highest phase possible is near the center of your target's shadow. This scientifically advantageous and much desired viewing position can reveal details about the atmosphere and the rings that cannot be observed in lower solar phase.
Images like these can only be taken while the sun is behind the planet, making them not only beautiful, but rare and precious.
September 2006 is the last time Cassini was able to capture such an unusual perspective on Saturn and its rings. With sufficient distance and time to make a full system mosaic, Cassini was at that time able to take the mosaic image that has been titled titled "In Saturn's Shadow." The mosaic was processed to look like natural color, with Earth putting in a special appearance. This made "In Saturn's Shadow" the most popular Cassini image to date.
The image that has been released today in honor of the 2012 holiday season does not contain Earth. Like the Sun, Earth is hidden behind the planet. However, Cassini took this mosaic image from a closer vantage point than the previous image and thus reveals more detail in the rings of Saturn. Also visible in the mosaic are two of Saturn's moons, Enceladus and Tethys, both of which are visible below the rings on the left side of the planet. Tethys is below and to the left, while Enceladus is higher and closer to the rings.
This new, beautifully colored mosaic is composed of 60 images taken in the violet, visible and near infrared part of the spectrum. The image looks toward the non-illuminated side of the rings about 19 degrees below the ring plane, captured at a distance of approximately 500,000 miles from Saturn.
"Of all the many glorious images we have received from Saturn, none are more strikingly unusual than those taken from Saturn's shadow," said Carolyn Porco, Cassini's imaging team lead based at the Space Science Institute in Boulder, Colo.
A joint endeavor between the U.S and Europe, the Cassini Solstice mission is managed by NASA's Jet Propulsion Laboratory (JPL) for NASA's Science Directorate. Designed and assembled by JPL, the orbiter's imaging team consists of scientists from the U.S., U.K., France and Germany.