Everyone on Earth is in Scientifically Significant New Image of Saturn
Tuesday, November 12 2013
MOSCOW, Idaho – Nov. 6, 2013 – A panorama of the majestic Saturn system, as it would be seen by human eyes, was unveiled today in a new mosaic from NASA's Cassini mission. It sweeps 404,880 miles across Saturn and its inner ring system, including all of Saturn's rings out to the E ring.
“This image shows the Saturn system from a completely different perspective than we could ever get from Earth. Basically, it is an eclipse of the Sun by Saturn, so we are seeing light filtered through the planet's atmosphere and the rings,” said Matt Hedman, an assistant professor of physics at the University of Idaho. “Seeing Saturn and its rings backlit by the sun like this not only provides us with unique scientific information, it makes for an exceptionally beautiful image. Even better, most of the inner solar system in the background, so everyone on Earth is in this picture.”
Hedman is a participating scientist on the Cassini project, along with associate physics professor Jason Barnes. Four UI students also are involved in Cassini-related research.
Cassini's imaging team processed 141 wide-angle images to create the panorama. The mosaic is part of Cassini's "Wave at Saturn" campaign, which marked the first time Earthlings had advance notice a spacecraft was taking their picture from planetary distances. A new version of the collage of photos shared by the public is also available, with the Saturn system as backdrop.
"In this one magnificent view, Cassini has delivered to us a universe of marvels: from spokes in Saturn's main rings to the spray erupting from the icy moon Enceladus, from the shadows of moons cast through the gorgeous blue E ring to the inner planets Venus, Mars, and our own planet Earth, far in the distance," said Carolyn Porco, Cassini's imaging team lead based at the Space Science Institute in Boulder, Colo. "And it did so on a day people all over the world, in unison, smiled in celebration at the sheer joy of being alive on a pale blue dot."
An annotated version of the mosaic labels the points of interest. Earth is a bright blue dot to the lower right of Saturn. Venus is a bright dot to Saturn’s upper left. Mars also appears, as a faint red dot, above and to the left of Venus.
Seven Saturnian moons are visible in the mosaic, including Enceladus on the left side of the image. Zooming in reveals the moon and the icy plume emanating from its south pole, supplying fine, powder-sized icy particles that make up the E ring.
The E ring, Saturn's second outermost ring, shines like a halo around Saturn and the inner rings. Because it is so tenuous, it is best seen with light shining from behind it, when the tiny particles are outlined with light due to the phenomenon of diffraction.
Scientists who focus on Saturn's rings are busy looking for patterns in optical bonanzas like these. When they use computers to increase dramatically the contrast of the images and change the color balance, for example, they are excited to see evidence for material tracing out the full orbits of the tiny moons Anthe and Methone for the first time.
“This mosaic provides a remarkable amount of high-quality data on Saturn’s diffuse rings, revealing all sorts of intriguing structures we are currently trying to understand," said Hedman. "The E ring in particular shows patterns that likely reflect disturbances from such diverse sources as sunlight and Enceladus’ gravity.”
Cassini does not attempt many images of Earth because the sun is so close to Earth that an unobstructed view would damage the spacecraft's sensitive detectors. Cassini team members looked for an opportunity when the sun would slip behind Saturn from Cassini's point of view. A good opportunity came on July 19, when Cassini was able to capture a picture of Earth and its moon, and a stately, multi-image backlit panorama of the Saturn system.
"With a long, intricate dance around the Saturn system, Cassini aims to study the Saturn system from as many angles as possible," said Linda Spilker, Cassini project scientist based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Beyond showing us the beauty of the Ringed Planet, data like these also improve our understanding of the history of the faint rings around Saturn and the way disks around planets form -- clues to how our own solar system formed around the sun."
Launched in 1997, Cassini has explored the Saturn system for more than nine years. NASA plans to continue the mission through 2017, with the anticipation of collecting much more data on Saturn, its rings and moons.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter and its two onboard cameras. The imaging team is based at the Space Science Institute, Boulder, Colo.
For more information about the Cassini mission, visit www.nasa.gov/cassini
For other recent news about UI’s work on the Cassini project, visit www.uidaho.edu/newsevents/item?name=ui-researchers-help-decode-new-view-of-saturns-moon-titan-contribute-to-cassini-mission
NASA Jet Propulsion Laboratory, Pasadena, Calif.
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