A backbone holding up the Milky Way is bending — and astronomers don't know why

The dusty backbone of our spiral arm of the Milky Way is waving.

We live near the end of a long, thin stream of gas, dust, and stars, which spirals outward from the center of the Milky Way. Our cosmic neighborhood is called the Orion Spur, and it’s sort of like a stellar side street between the main pair of spiraling “arms” that give the Milky Way its trademark pinwheel shape. The backbone of the Orion Spur is a chain of dense gas clouds called nebulae, and all along that chain of nebulae, clumps of gas are collapsing into clusters of bright new stars. READ MORE FROM INVERSE