NASA Spacecraft Sees Cosmic Snow Storm During Comet Encounter
Pasadena, California, November 19, 2010 /PN/ The EPOXI mission's recent encounter with comet Hartley 2 provided the first images clear enough for scientists to link jets of dust and gas with specific surface features. NASA and other scientists have begun to analyze the images.
The EPOXI mission spacecraft revealed a cometary snow storm created by carbon dioxide jets spewing out tons of golf-ball to basketball-sized fluffy ice particles from the peanut-shaped comet's rocky ends. At the same time, a different process was causing water vapor to escape from the comet's smooth mid-section. This information sheds new light on the nature of comets and even planets.
"When we first saw all the specks surrounding the nucleus, our mouths dropped," said Pete Schultz, EPOXI mission co-investigator at Brown University. "Stereo images reveal there are snowballs in front and behind the nucleus, making it look like a scene in one of those crystal snow globes."
Icy Particle Spray. Most of these particles are traveling with the nucleus. They are fluffy "snowballs" about 3 centimeters to 30 centimeters (1 inch to 1 foot) across. Image Credit: NASA/JPL-Caltech/UMD/Brown
Hartley 2, Close Up. This image from the High-Resolution Instrument on NASA's EPOXI mission spacecraft shows part of the nucleus of comet Hartley 2. The sun is illuminating the nucleus from the right. A distinct cloud of individual particles is visible. This image was obtained on Nov. 4, 2010, the day the EPOXI mission spacecraft made its closest approach to the comet. Image Credit: NASA/JPL-Caltech/UMD