渦巻き状の銀河

 

http://www.sciencedaily.com/releases/2008/01/080131094056.htm

 

The magnificent spiral arms of the nearby galaxy Messier 81. Astronomers believe that both the universe and galaxies are held together by the gravitational attraction of a huge amount of unseen material, now commonly referred to as dark matter. (Credit: NASA/JPL/Caltech/Harvard-Smithsonian Center for Astrophysics)

 

Only 4% of the universe is made of known material - the other 96% is traditionally labelled into two sectors, dark matter and dark energy.

 

 

Einstein Ring:   http://www.sciencedaily.com/releases/2007/02/070207093405.htm

 

 

中村 8-7-2009