Comet Halley

Comet Halley, officially designated 1P/Halley, more generally known as Halley's Comet after Edmond Halley, is the best-known and the brightest of the "short-period" comets from the Kuiper belt that visit the inner solar system in years or decades-long orbits rather than the millennial periods of comets from the Oort cloud.

Composition

The nucleus of Halley's comet is potato-shaped with dimensions around

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

8 by 8 by 16 kilometers. The density of the nucleus is between

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

one tenth and one quarter times the density of water. The nucleus is very

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

dark, reflecting only around 4% of incident light.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

http://www.astronomynotes.com/solfluf/s7.htm

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The Giotto space probe found the comet's surface to be rich in carbon. Of the volume of material ejected by Halley, 80% was water, 10% carbon monoxide, and 2.5% a mix of methane and ammonia. Other hydrocarbons, iron, and sodium were detected in trace amounts.

Related Topics:
Giotto space probe - Carbon - Water - Carbon monoxide - Methane - Ammonia - Hydrocarbons - Iron - Sodium

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Cyanogen gas is present in trace amounts.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Material from the comet is responsible for two meteor showers each year, the Eta Aquarids in May and the Orionids in October.

Related Topics:
Meteor showers - Eta Aquarids - Orionids

~ ~ ~ ~ ~ ~ ~ ~ ~ ~