The Milky Way galaxy, on Sept. 7, 2013.
Astronomers in the U.K. have counted not two but four arms swirling out from the center of the Milky Way.
According to NPR, the updated arm-count comes from a 12-year galactic survey of massive young stars. The short-lived stars have no time to drift outside of the arms and therefore make convenient markers for the galaxy’s appendages.
Taken together, they paint a very different picture of the Milky Way, which up until now had been inadvertently amputated in its two-armed renderings, and can now be restored to its true, four-armed splendor.
[NPR]