dark matter

Via: Daily Galaxy
  • -
  • Vote
  • -
The Milky Way is smaller than astronomers previously thought, according to new research. For the first time, scientists have been able to precisely measure the mass of the galaxy that contains our solar system. Researchers have found that the Milky Way is approximately half the weight of ou neighboring galaxy – Andromeda – which has a similar structure to our own. The Milky Way and Andromeda are the two largest in a region of galaxies which astronomers call the Local Group.

In this new study, researchers were also able to work out the mass of invisible matter found in the outer regions of both galaxies, and reveal their total weights. They say 90 per cent of both galaxies' matter is invisible. Scientists say that Andromeda's extra weight must be present in the form of dark matter, the little-understood invisible substance which makes up most of the outer regions of galaxies. They estimate that Andromeda contains twice as much dark matter as the Milky Way, causing it to be twice as heavy.
Via: MNN
  • -
  • Vote
  • -
Two spacecraft have detected a possible signal of dark matter, the mysterious, invisible stuff that makes up most of the material universe.

NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton satellite spotted a spike of X-ray emission coming from more than 70 different galaxy clusters. While the origin of the X-rays remains unclear at the moment, they could be generated by the decay of a certain type of dark-matter particle, scientists said.

"We know that the dark matter explanation is a long shot, but the payoff would be huge if we're right," study lead author Esra Bulbul, of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, said in a statement. "So we're going to keep testing this interpretation and see where it takes us." [Gallery: Dark Matter Throughout the Universe]