|
|
|
|
|
Cassini reveals spectacular evidence of an active moon CASSINI PHOTO RELEASE Posted: December 6, 2005 Jets of fine, icy particles streaming from Saturn's moon Enceladus were captured in recent images from NASA's Cassini spacecraft. The images provide unambiguous visual evidence that the moon is geologically active. "For planetary explorers like us, there is little that can compare to the sighting of activity on another solar system body," said Dr. Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, Colo. "This has been a heart-stopper, and surely one of our most thrilling results."
The fainter, extended plume stretches at least 186 kilometers (300 miles) above the surface of Enceladus, which is only 186 kilometers wide. Cassini flew through the plume in July, when it passed a few hundred kilometers above the moon. During that flyby, Cassini's instruments measured the plume's constituent water vapor and icy particles. Imaging team members analyzed images of Enceladus taken earlier this year at similar viewing angles. It was a rigorous effort to demonstrate that earlier apparitions of the plumes, seen as far back as January, were in fact real and not due to imperfections in the camera. The recent images were part of a sequence planned to confirm the presence of the plumes and examine them in finer detail. Imaging team member Dr. Andrew Ingersoll from the California Institute of Technology in Pasadena, said, "I think what we're seeing are ice particles in jets of water vapor that emanate from pressurized vents. To form the particles and carry them aloft, the vapor must have a certain density, and that implies surprisingly warm temperatures for a cold body like Enceladus."
"In some ways, Enceladus resembles a huge comet," said Dr. Torrence Johnson, imaging team member from NASA's Jet Propulsion Laboratory in Pasadena. "Only, in the case of Enceladus, the energy source for the geyser-like activity is believed to be due to internal heating by perhaps radioactivity and tides rather than the sunlight which causes cometary jets." The new data also give yet another indication of how Enceladus keeps supplying material to Saturn's gossamer E ring. The Cassini-Huygens mission is a cooperative project of NASA, the European and Italian Space Agencies. JPL, a division of the Caltech, manages the mission for NASA's Science Mission Directorate. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute. |
|
|
|
 |
||||||||||||||||||||||
Scientists marvel at the achievements made by the orbiting Hubble Space Telescope in this produced movie looking at the crown jewel observatory that has served as our window on the universe.
10 years ago: The Solar and Heliospheric Observatory, a joint European and American Sun-watching probe, blasts off from Cape Canaveral aboard a Lockheed Martin Atlas 2AS rocket.
The European Space Agency's Huygens probe, launched from NASA's Cassini spacecraft, descended through the atmosphere of Saturn's moon Titan and landed on its mysterious surface in January. Scientists hold this news briefing to report on new results from the daring mission.
Project scientists working on the European Space Agency's Mars Express spacecraft now orbiting the Red Planet hold a news conference to announce some interesting results from the ongoing mission.
Mercury astronaut John Glenn becomes the first American to orbit the Earth on February 20, 1962, when he is launched aboard Friendship 7.
