Really dark

Black holes, that is. It's long been inferred that a monster black hole lurked at the center of our galaxy. The evidence is now better than ever. See "Confirmed: a monster black hole at the heart of the Milky Way." A key quote:

New observations by the European Space Observatory (ESO) show clumps of gas swirling around at about 30% of the speed of light on a circular orbit just outside what astronomers conclude is the black hole’s event horizon. 

It’s the first time material has been seen o...