|   | 
Credit: TRACE Project,    
NASA    
   
Explanation:
Why does the Sun flare?     
   
Unpredictably, our    
Sun unleashes tremendous    
flares   
expelling hot gas into the    
Solar   
System    
that can affect satellites, astronauts, and power grids on Earth.     
   
This close up of an active region on the Sun that produced a powerful    
X-class flare    
was captured by the orbiting    
TRACE satellite.   
   
Clicking on the image should bring up a movie that shows the evolution of    
Active Region 9906 over about four hours.    
   
The glowing gas flowing around the relatively stable    
magnetic   
field loops above the    
Sun's photosphere    
has a temperature of over ten million degrees    
Celsius.   
   
These flows occurred after violently unstable    
magnetic   
reconnection events above the Sun produced the flare.     
   
Many things about    
solar active regions are not well    
understood including the presence of    
dark regions that appear to move inward during the movie.     
   
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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: Sun
Publications with words: Sun
See also:
