|
|
|
|
|
Scientists discover Pluto kin is member of Saturn family NASA/JPL NEWS RELEASE Posted: May 7, 2005 Saturn's battered little moon Phoebe is an interloper to the Saturn system from the deep outer solar system, scientists have concluded. The new findings appear in the May 5 issue of the journal Nature.
Cassini flew by Phoebe on its way to Saturn on June 11, 2004. Little was known about Phoebe at that time. During the encounter, scientists got the first detailed look at Phoebe, which allowed them to determine its makeup and mass. With the new information they have concluded that it has an outer solar system origin, akin to Pluto and other members of the Kuiper Belt. "Cassini is showing us that Phoebe is quite different from Saturn's other icy satellites, not just in its orbit but in the relative proportions of rock and ice. It resembles Pluto in this regard much more than it does the other Saturnian satellites," said Dr. Jonathan Lunine, Cassini interdisciplinary scientist from the University of Arizona, Tucson. Phoebe has a density consistent with that of the only Kuiper Belt objects for which densities are known. Phoebešs mass, combined with an accurate volume estimate from images, yields a density of about 1.6 grams per cubic centimeter (100 pounds per cubic foot), much lighter than most rocks but heavier than pure ice, which is about 0.93 grams per cubic centimeter (58 pounds per cubic foot). This suggests a composition of ice and rock similar to that of Pluto and Neptune's moon Triton. Whether the dark material on other moons of Saturn is the same primordial material as on Phoebe remains to be seen. 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 in Pasadena, manages the Cassini mission for NASA's Science Mission Directorate, Washington, D.C. |
|
|
|
 |
|||||||||||||||||||||
Watch shuttle Discovery's countdown dress rehearsal that ends with a simulated main engine shutdown and post-abort safing practice. (13min 19sec file)
The five-man, two-woman astronaut crew departs the Operations and Checkout Building to board the AstroVan for the ride to launch pad 39B during the Terminal Countdown Demonstration Test countdown dress rehearsal. (3min 07sec file)
After breakfast, the astronauts don their launch and entry partial pressure suits before heading to the pad. (3min 14sec file)
Dressed in festive Hawaiian shirts, Discovery's seven astronauts are gathered around the dining room table in crew quarters for breakfast. They were awakened at 6:05 a.m. EDT to begin the launch day dress rehearsal at Kennedy Space Center. (1min 57sec file)
As part of their training at Kennedy Space Center, the Discovery astronauts learn to drive an armored tank that would be used to escape the launch pad and receive briefings on the escape baskets on the pad 39B tower. (5min 19sec file)
Shuttle Discovery's astronauts pause their training at launch pad 39B to hold an informal news conference near the emergency evacuation bunker. (26min 11sec file)
The 2005 class of Gordon Fullerton, Joe Allen and Bruce McCandless is inducted into the U.S. Astronaut Hall of Fame at the Saturn 5 Center on April 30. (1hr 24min 55sec file)
This video by Lockheed Martin relives the storied history of the Titan rocket family over the past five decades. (4min 21sec file)
Footage from that various Titan rocket launches from the 1950s to today is compiled into this movie. (6min 52sec file)