Harold Navarro/Flickr (CC BY-ND 2.0)

Light from other galaxies is contributing to your suntan

The glow—or burn, perhaps—you get after spending a day outside isn’t just from the sun, Popular Science reports. A new study says that at least 10-trillionths of your sun tan is caused by light that has traveled billions of years from outside the Milky Way. As noted in the study published online today in The Astrophysical Journal, this intergalactic light comes from the cores of stars or matter as it spirals into a supermassive black hole all the way to Earth.