Composite image of galaxy NGC 6240 (photo)

This image of NGC 6240 contains X-ray data from NASA's Chandra X-ray Observatory (red, orange, and yellow) that has been combined with an optical image from the Hubble Space Telescope. Scientists think two giant black holes – seen as the bright point-like sources in the middle of the image -- are a mere 3,000 light years apart after spiraling toward each other beginning about 30 million years ago. It is estimated that the two black holes will eventually drift together and merge into a larger black hole some tens or hundreds of millions of years from now.