Is it aliens? Sure sounds like aliens—but these strange, glowing patches over Pluto are actually something else (almost) as mysterious.

NASA’s New Horizons snapped this photo of sunlight streaming through Pluto’s haze haze during the spacecraft’s close approach on July 14, 2015. But, as researchers looked closer at the photo, a question emerged: Uh, what’s with that weird glowing patch in the upper right hand corner?