Two Supermassive Black Holes Orbiting Each Other. Stephen Hawking Was Right

The Moon orbits around the Earth. The Earth orbits around the Sun. And out in the distant Universe, astronomers have found a system that takes this logical progression to its most extreme. Theres a system where a supermassive black hole with millions of times the mass of the Sun orbits another black hole with billions of times the mass of the Sun. How astronomers discovered this incredible interaction took careful observations, imagination, and the hard work of the Spitzer Space Telescope, taken during its final years of operation. Our Book is out Audio Podcast version: ITunes: RSS: Weekly email newsletter: Weekly Space Hangout: Astronomy Cast: htt