Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

May 14, 1997
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

Hale-Bopp's Fickle Ion Tail
Credit and Copyright: A. Dimai, D. Ghirardo and R. Volcan (Col Druscie Obs., ACC)

Explanation: What's happening to Comet Hale-Bopp's blue ion tail? The comet's ion tail is fluctuating more rapidly as it passes a region of changing solar wind. As the comet passes from north to south, it crosses the plane of the Sun's equator, where the solar magnetic field changes direction. Ions from the solar wind, which cause Comet Hale-Bopp's ion tail, act unpredictably here. Therefore, Comet Hale-Bopp's ion tale may show unusual structure or even a disconnection - where the tail appears to break off and then reestablish itself later. The above picture, taken April 30th, indeed shows unusual structure in the blue ion tail.

Tomorrow's picture: Hale-Bopp: Climbing Into Southern Skies

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.