The latest NASA "Image of the Day" image.

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This image taken by the Hubble Space Telescope in 2009  features Saturn with the rings edge-on and both poles in view, offering  a stunning double view of its fluttering auroras. 
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Created by the  interaction of the solar wind with the planet's magnetic field, Saturn's  aurorae are analogous to the more familiar northern and southern lights  on Earth. 
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At the time when Hubble snapped this picture, Saturn was  approaching its equinox so both poles were equally illuminated by the  sun's rays. At first glance the light show of Saturn's auroras appears  symmetric at the two poles. However, astronomers discovered some subtle  differences between the northern and southern auroras, which reveal  important information about Saturn's magnetic field. 
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The northern  auroral oval is slightly smaller and more intense than the southern one,  implying that Saturn's magnetic field is not equally distributed across  the planet; it is slightly uneven and stronger in the north than the  south. 
Image Credit: NASA/ESA/STScI/University of Leicester
Τετάρτη, 23 Μάρτιος 2011 6:00:00 πμ
 
 
 
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