The Milky Way Once <br />Had a Sister Galaxy, but Andromeda Ate It University of Michigan scientists <br />have discovered that we once had a sister <br />galaxy that was consumed by the Andromeda <br />galaxy about two billion years ago. Scientists have long thought that <br />the halo of stars surrounding Andromeda <br />indicated that the large galaxy most likely <br />ate smaller surrounding galaxies. However, there was never <br />really a way to figure out <br />just how many galaxies <br />it had consumed. Through the use of computer modeling, researchers are finding that most of Andromeda's <br />outer halo of stars was most <br />likely made from one larger galaxy. Enter our sister galaxy, M32p. This galaxy was third in size to Andromeda <br />and the Milky Way. Eric Bell, co-author of paper in 'Nature Astronomy' This discovery also helps to shed light <br />on Andromeda's small satellite galaxy, M32. <br />Scientists have never been able <br />to figure out where it came from. Under the theory of Andromeda eating a sister galaxy, they can extrapolate that it originated <br />as a remnant of M32p. Side note: Our galaxy will collide with Andromeda as well. But don't stress too much. <br />It's destined to arrive in four billion years.
