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Credit: John Pane  
  
Explanation:
How has Comet Holmes changed?  
  
Since  
brightening unexpectedly by nearly one  
million fold in late October, the last three months have found the  
coma of  
Comet 17P/Holmes both expanding and fading.  
  
This  
spectacular  
composite image shows how the coma and tail of Comet  
Holmes have changed.  
  
Due to Earth's changing vantage point,  
Comet Holmes,  
out beyond the  
orbit of  
Mars, was seen in November nearly head-on, but in recent months  
is seen more from the side.  
  
Additionally,  
the comet's  
motion,  
when combined with Earth's changing perspective, has caused the comet to  
have shifted relative to the background stars.  
  
The curved path of  
Comet Holmes shows it to be undergoing  
apparent  
retrograde motion as the Earth orbits  
quickly in front of it.  
  
The extent of the coma currently makes  
Comet Holmes  
over five times the physical size of our Sun.  
  
Anecdotal evidence holds that the  
comet is hard to see without long photographic exposures,  
but on such exposures the comet may still be an  
impressive sight.  
  
   
  
 
  
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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:

