Astronomy Picture of the Day
    


Gas and Snow Jets from Comet Hartley 2
<< Yesterday 23.11.2010 Tomorrow >>
Gas and Snow Jets from Comet Hartley 2
Credit & Copyright: NASA, JPL-Caltech, UMD, EPOXI Mission
Explanation: Unusual jets have been discovered emanating from Comet Hartley 2. The EPOXI spacecraft imaged the jets in unprecedented detail during its flyby of the comet earlier this month. Pictured above, sun-illuminated jets shoot away from the two-kilometer long decaying iceberg that orbits the Sun between Earth and Jupiter. Comet Hartley 2 became active recently as it neared the Sun and sunlight warmed the comet. Preliminary analyses of images like that shown above indicate that the smooth regions around the middle are porous and leak frozen water vapor directly out into space. Unexpectedly, however, the rough regions at either end appear to shoot carbon dioxide jets that expel fluffy snowballs, some as large as basketballs, from the nucleus. Many of the dots in the above image are thought to be snowballs. The unusual jets will continue to be studied, and may yield further clues as to how comets and asteroids formed and evolved during the early years of our Solar System. Comet Hartley 2 is slowly evaporating and may completely break up over the next 1,000 years.

January
February
March
April
May
June
July
August
September
October
November
December
 < November 2010  >
Mo Tu We Th Fr Sa Su
1234567
891011121314
15161718192021
22232425262728
2930




Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: comet
Publications with words: comet
See also:
All publications on this topic >>