Astronomers have discovered a “Great Wave” spreading across the Milky Way in a new map of thousands of stars.

An edge-on image of the Milky Way, obtained using data from the European Space Agency's Gaia star-mapping mission. A clear “wave” of stellar motion is visible, indicated by vertical arrows. (Image credit: ESA/Gaia/DPAC, S. Payne-Wardenaar, E. Poggio et al (20





