Astronomy Picture of the Day
    


What are Comet Tails Made Of?
<< Yesterday 25.03.1996 Tomorrow >>
What are Comet Tails Made Of?
Credit & Copyright: Jim Martin, Huntsville AL, Courtesy "Night of the Comet" (NASA / Ames)
Explanation: The tail of comet Hyakutake, visible in this recent color image, is composed of dust and gas driven off the icy comet nucleus by the Sun's heat and blown away by the solar wind. Bathed in solar ultraviolet light, the gas molecules break down and are excited, producing a characteristic glow. This glow is responsible for visible light from the tail and astronomers using spectroscopes can identify the compounds involved. The close passage of Hyakutake presents an excellent chance to use this technique to explore the composition of its tail. Typical comet gas tail constituents are simple combinations of hydrogen, carbon, nitrogen, and oxygen - for example, H20 (water), CO (carbon monoxide), and CN (cyanogen) are common. In fact, the poisonous CO and CN compounds were seen in the spectrum of Halley's comet during its 1910 apparition. This caused some public concern at the time as the Earth was expected to pass through Halley's tail! However, stretching for millions of miles, comet tails are extremely thin and tenuous and don't pose a danger to the Earth's atmosphere.

Latest Comet Hyakutake images: JPL, Crni Vrh Observatory, Slovenia, Fayetteville Observer-Times, NASA's Night of the Comet

January
February
March
April
May
June
July
August
September
October
November
December
 < March 1996  >
Mo Tu We Th Fr Sa Su




123
45678910
11121314151617
18192021222324
25262728293031
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 >>