From our perch here on Earth, it’s impossible for most of us to notice changes happening in our home galaxy, the Milky Way. Astronomers, on the other hand, have tools at their disposal that make observing trends in our galaxy a bit easier, and one development, in particular, is leaving scientists scratching their heads: The Milky Way is warping. Our entire galaxy isn’t twisting or deforming, of course, but the edge of the spiral is acting quite odd. The outer lip is wobbling and warping in a manner that defies most explanation, and researchers are doing their best to wrap their heads around it.
Using data from the European Space Agency’s Gaia survey mission, astronomers got a detailed look at the warping edge and began to test theories as to why it exists. Some of the theories that seemed plausible at first but didn’t hold up under further examination.
As Futurism notes, one such theory suggested that the inner galaxy was spinning at an angle to the outer edge, causing the lip of the galaxy to wobble and wave. However, comparing the speeds of rotation between the various regions of our galaxy and the warping motion seemed to squash that theory.
Now, the best current guess is that our galaxy is about to swallow up something quite large. A much smaller galaxy orbiting the Milky Way may ultimately be responsible for the warp observed by scientists. The pull of the smaller galaxy on our own may be causing the edge of our galaxy to warp and twist.
But if that’s the case, which smaller galaxy is behind all of this weirdness? The scientists suggest that the tiny dwarf galaxy Sagittarius could be to blame. It’s already believed that the Milky Way is gradually swallowing Sagittarius, and if that’s the case, that incredible event may be enough to cause the mighty Milky Way to warp, but they can’t say for certain.