New data from ESA’s Gaia telescope reveal a massive wave rippling through the Milky Way’s disc, affecting stars tens of thousands of light-years from the center.

Unlike the previously known rotation, warp, and wobble of the galaxy, this newly observed wave shows stars oscillating vertically above and below the disc in a pattern resembling a stadium “wave.”

Astronomers tracked the motion using young giant stars and Cepheids, suggesting that the galactic gas may also participate in the ripple.

The wave’s origin is uncertain, but it could stem from a past collision with a dwarf galaxy and may be related to—but is much larger than—the local Radcliffe Wave, the European Space Agency has reported.

Upcoming Gaia data releases will provide even more precise maps to study this phenomenon.