Dark matter in galaxies may be weakened or absent altogether
The standard view of cosmic evolution may be challenged by the discovery of a huge galaxy that appears to lack dark matter. Dark matter, which makes up about 85% of the matter in the universe, is missing from NGC 1277, a galaxy in the Perseus galaxy cluster. The galaxy, located 240 million light-years from Earth, is the first Milky Way-sized cluster of stars, planets, dust, and gas to be found to lack dark matter.
Blast from the past: a gamma-ray burst hit the Earth from a distant exploding star
A huge burst of gamma rays detected by the European Space Agency’s Integral space telescope has hit Earth. The explosion caused significant disturbances in the ionosphere of our planet. Such disturbances are usually associated with events involving energetic particles on the Sun, but this event was the result of the explosion of a star nearly two billion light years away. Analysis of the explosion’s aftermath could provide information about mass extinctions in Earth’s history, the European Space Agency said.