Ever wonder how Eta Carinae got its unusual shape? This animation shows how it may have started—as a triple-star system—before one of the stars bulks up by taking most of the material from one of its siblings. The stars start to trade places and when two merge an explosion of epic proportions produces bipolar ejections from the giant star. The surviving companion star settled into an elongated orbit around the merged pair, passing through the monster star's outer gaseous layers every 5.5 years.