<\/p>\n Like ripples in a pond, the wave has a very large influence: It affects stars between 30,000 and 65,000 light-years away from the galaxy’s center, ESA officials said in a statement<\/a>. That’s a large percentage of the Milky Way<\/a>, which is roughly 100,000 light-years across.<\/p>\n You may like<\/p>\n Astronomers still don’t know what started the motion. It could have been a past collision<\/a> with a smaller, dwarf galaxy that caused the large shake, ESA officials said, but more investigation is required to answer that question.<\/p>\n The results were published July 14 in the journal Astronomy & Astrophysics<\/a>.<\/p>\n Mapping the wave<\/p>\n Gaia mapped the speeds and motions of stars for nearly a dozen years. In 2020, the telescope observed that the disk of the Milky Way wobbles like a spinning top<\/a>. The newfound wave was charted by following the movements and positions of young, giant stars as well as a set of Cepheids \u2014 stars that have predictable-but-variable brightness.<\/p>\n “Because young giant stars and Cepheids move with the wave, the scientists think that gas in the disc might also be taking part in this large-scale ripple,” ESA officials wrote in the statement. “It is possible that young stars retain the memory of the wave information from the gas itself, from which they were born.”<\/p>\n ESA officials likened the galactic wave to “the Wave” done by a crowd at a stadium: In a group movement starting from one side of the stadium and moving section by section to the other side, individuals rise from their seats, fully stand up with their arms extended, and then sit back down.<\/p>\n \n A clear wave pattern emerges when looking at the motions of stars at the edges of the Milky Way, as seen here in this map of Gaia data. (Image credit: ESA\/Gaia\/DPAC, S. Payne-Wardenaar, E. Poggio et al (2025))<\/p>\n A similar type of wave motion is visible when our galaxy is observed edge-on. Such vertical motions, represented by arrows, show ripples of movement far across the Milky Way’s disk.<\/p>\n “This observed behaviour is consistent with what we would expect from a wave,” lead author Eloisa Poggio<\/a>, an astronomer at the National Institute of Astrophysics in Italy, said in the statement.<\/p>\n![\"An](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2025\/10\/8Cn9sYcEWPf58wiTHDb2cg.jpg\")
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