Astronomy Picture of the Day
    


Halley s Nucleus: An Orbiting Iceberg
<< Yesterday 5.08.2000 Tomorrow >>
Halley s Nucleus: An Orbiting Iceberg
Credit & Copyright: MPAE
Explanation: What does a comet nucleus look like? Formed from the primordial stuff of the solar system, it is thought to resemble a very dirty iceberg. But for active comets, telescopic images only reveal the surrounding cloud of gas and dust, the comet's coma, and the characteristic cometary tails. In 1986, the European spacecraft Giotto encountered the nucleus of Halley's comet as it approached the sun. Data from Giotto's camera was used to generate this enhanced image of the potato shaped nucleus which measures roughly 15 kilometers across. It shows surface features on the dark nucleus against the bright background of the coma as the icy material is vaporized by the Sun's heat. Every 76 years Comet Halley returns to the inner solar system and each time the nucleus sheds about a 6 meter deep layer of its ice and rock into space. This debris composes Halley's tails and leaves an orbiting trail responsible for the Orionids meteor shower.

January
February
March
April
May
June
July
August
September
October
November
December
 < August 2000  >
Mo Tu We Th Fr Sa Su

123456
78910111213
14151617181920
21222324252627
28293031


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: nucleus - comet nucleus - comet Halley
Publications with words: nucleus - comet nucleus - comet Halley
See also:
All publications on this topic >>