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Credit: The MAXIMA Collaboration,  
NSF 
Explanation:
No matter which direction you look,  
no matter what type of light you see,  
the sky glows - but why?   
 
The sources of many of these  
background radiations have remained long-standing puzzles,  
but this millennial year brought some partial resolutions.   
 
In X-ray light the recently launched spacecraft  
Chandra and  
XMM  
resolved much of the seemingly uniform  
X-ray background into many discrete sources, many of which appear to be  
black holes at the centers of galaxies  
accreting matter.   
 
In  
microwave light, the  
BOOMERANG and  
MAXIMA-1 missions  
resolved with  
new clarity  
the seemingly uniform  
microwave background.  
 
The size and distribution of these  
spots indicates a  
geometrically flat universe,  
which, when combined recent  
supernovae results,  
indicate a universe with an accelerating expansion rate  
filled with  
dark matter and  
dark energy. 
 
Pictured above, a map spanning ten degrees of the  
microwave sky resolves the  
microwave background  
into hot and cold spots, as indicated in microkelvins. 
 
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Based on Astronomy Picture
Of the Day
Publications with keywords: cosmic microwave background radiation
Publications with words: cosmic microwave background radiation
See also:

