News Space This just in: Milky Way as massive as 3 trillion suns Heftier size puts our galaxy on par with neighboring Andromeda, implying a closer collision date. Findings also suggest Milky Way has four spiral arms. By Ron Cowen January 5, 2009 at 7:44 pm - More than 2 years ago Share this:Share Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print LONG BEACH, Calif. — Hey Andromeda, you’d better watch out. Turns out your little brother, the Milky Way galaxy, isn’t so little after all.