An unusual pair of galaxies travel through the interstellar cosmos in this striking image obtained by NASA's Hubble Space Telescope. The unusual pair are jointly called Arp 116, but are composed of a large elliptical galaxy known as M60 and a smaller spiral galaxy called NGC 4647.
The pair lies in the Virgo cluster of galaxies, where M60 is the third brightest object. It has a diameter of 120,000 light-years and a mass about 1 trillion times that of the sun. A massive black hole with a mass of about 4.5 billion times that of the sun lies at its center. NGC 4647 is about two-thirds the size of M60 and has a mass about the same as our own Milky Way galaxy. The two galaxies lie about 54 million and 63 million light-years away from Earth, respectively, so their apparent size difference in the image is very close to the actual difference.