In a looming collision of giants, two supermassive black holes are drifting toward a violent merger and an eruption of energy that will warp the fabric of space. It is all happening in a bright galaxy 400-million light-years away.
Images from the Chandra X-ray Observatory have captured for the first time the circling dance of two black holes _ each millions of times the mass of the sun _ as they whirl around each other.
"This is the first time we have ever identified a binary black hole," said Stefanie Komossa, an astronomer at the Max Planck Institute for Extraterrestrial Physics and the co-author of a study of the double black hole. "This is the aftermath of two galaxies that collided sometime in the past."
Each of the galaxies was about the size of the Milky Way, Komossa said Tuesday at a news conference. When they blended, the galaxies formed a single, extraordinarily bright galaxy known as NGC6240. Because of its distance from the Earth, the image now seen is 400-million years old.
Astronomers said the merger is a glimpse of what may await the Earth's galaxy. Astronomers believe that in about 4-billion years, the Milky Way and the Andromeda galaxy will collide and merge.
When the black holes merge, gravitational waves will race across the universe, said Gunther Hasinger, a Max Planck astrophysicist and co-author of the study.
"A whole planet could be squeezed by an inch or so every few minutes," depending on how close it is to the merged black holes, said Steinn Sigurdsson, a Pennsylvania State University astronomer. Satellites would jiggle and navigation equipment could wobble momentarily, he said.