Have Astronomers Finally Found Dark Matter?

By Michael D. Lemonick, for National Geographic

April 1,2015; 7:30AM,EDT

 

 

The following is an excerpt from National Geographic
"It's too early to say for certain, but astronomers may have picked up a new clue to the nature of dark matter-invisible cosmic stuff with at least five times the mass of all the visible stars and galaxies combined."
Credit: Vasily Belokurov, Sergey Koposov (Institute of Astronomy, Cambridge)
"The clue comes in the form of gamma rays, a kind of light the human eye can't detect, emanating from a newly discovered dwarf galaxy called Reticulum 2. Reticulum 2, which hovers beyond the edge of the Milky Way, about 98,000 light-years from Earth, is fascinating in its own right: No more than a few thousand stars (compared with the Milky Way's hundred billion or more) embedded in a clump of dark matter, it's similar to the first tiny galaxies that appeared after the big bang. (See "Galaxy Hunters-The Search for Cosmic Dawn" to learn more about the earliest galaxies.)"