Nearby Galaxy Boasts Two Monster Black Holes, Both Active

Zoom into Markarian 739, a nearby galaxy hosting two monster black holes. Using NASA's Swift and Chandra, astronomers have shown that both black holes are producing energy as gas falls into them. The object is only the second-known binary active galactic nucleus within half-a-billion light-years. (No audio. Animation begins with visible light view of Markarian 739 and transitions into an artistic rendering of the two black holes. Credit: NASA's Goddard Space Flight Center)