Somewhere along the way to charting the most detailed 3D map of our galaxy ever, the Gaia project hit a snag. Literally.

Something had blown a massive hole in the Milky Way. Ana Bonaca of the Harvard-Smithsonian Center for Astrophysics discovered the rift, presenting her findings at a recent meeting of the American Physical Society — but we're literally in the dark on what caused it.

Read more at MNN.