The force of gravity locks smaller things in place around big ones. This holds true for galaxies, including our own, which maintain systems of satellite galaxies (for example, our Large and Small Magellanic Clouds). While the current standard cosmological model used by astronomers to describe and understand the universe states that these satellites should be randomly distributed and orbit around their parent galaxy in a disorderly fashion, new observations have just shown, for the third time, that this is not the case.
The results, published today in
Science, show that the satellite galaxies surrounding Centaurus A, a well-known and relatively nearby galaxy 13 million light-years away, are orbiting not only in a single plane, but in a nice, orderly fashion as well. Such observations confirm what astronomers have already seen around our own Milky Way and the Andromeda Galaxy, but fly in the face of the standard cosmological model, which say that such systems should be rare — as in, 0.5 percent of galaxies. But at three for three, astronomers have seen it in 100 percent of systems, instead.