14 DAY TRIAL // Astronomers with the Harvard-Smithsonian Center for Astrophysics claim to have identified as many as 11 so-called runaway galaxies that were somehow cast out of their home cluster and that are now exiles racing through space.
The galaxies, described in a paper in the journal Science, are all compact ellipticals. This means that they are considerably smaller than the Milky Way and its siblings, and pack a fairly small number of stars.
Scientists suspect that each of the newly discovered runaway galaxies was once part of a binary system. As illustrated in the image accompanying this article, they became exiles when a third galaxy came into the picture and chased them away from home.
These days, the runaways are a long distance from other galaxies or galaxy clusters. Basically, they are isolated in space. “These galaxies are facing a lonely future,” says astronomer Igor Chilingarian.
Then again, it looks like the exiles did their best to get as far away from their brethren as possible. According to Igor Chilingarian, they are traveling at about 6 million miles per hour (9.6 million kilometers per hour).
By comparison, individual stars that get thrown out of their cosmic home are usually seen moving through space at about 1 million miles per hour (1.6 million kilometers per hour).