NASA spacecraft provides first clear images of cosmic snow storm

[News_Editor]

NASA spacecraft provides first clear images of cosmic snow storm

2010-11-19 16:48:42 GMT+7 (ICT)

PASADENA, CALIFORNIA (BNO NEWS) -- The National Aeronautics and Space Administration (NASA) on Thursday announced that the EPOXI mission spacecraft has provided the first clear images of a cosmic snow storm during its encounter with comet Hartley 2.

The 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.

The images will help scientists to link jets of dust and gas with specific surface features. In addition, the data will provide new information on the nature of comets and even planets. Scientists compared the new data to data from a somewhat different comet the spacecraft previously visited in 2005, comet Tempel 1.

"This is the first time we've ever seen individual chunks of ice in the cloud around a comet or jets definitively powered by carbon dioxide gas," said Michael A'Hearn, lead investigator for the spacecraft at the University of Maryland. "We looked for, but didn't see, such ice particles around comet Tempel 1."

The Hartley 2 comet acts differently as carbon dioxide explains why the smooth and rough areas scientists saw respond differently to solar heating, and have different mechanisms by which water escapes from the comet's interior.

Stereo images revealed there are snowballs in front and behind the nucleus. Also, the smooth area of comet Hartley 2 looks and behaves like most of the surface of Tempel 1, with water evaporating below the surface and percolating out through the dust. However, the rough areas of Hartley 2 are very different as they have carbon dioxide jets spraying out ice particles.

Engineers at NASA's Jet Propulsion Laboratory have been looking if the ice particles damaged the spacecraft. So far, particles hit the spacecraft on nine occasions without damaging it. The particles are estimated to weigh slightly less than the mass of a snowflake.

Scientists still need more detailed analysis to determine how long this snow storm has been active, and also to determine the cause of the differences in activity between the middle and ends of the comet.

-- © BNO News All rights reserved 2010-11-19