The Milky Way's Dark Halo is Flattened and Twisted express
The Milky Way's stellar disk is like a glowing pinwheel, and dark matter is an invisible cloud around it. For the first time, its shape has been precisely measured. Astronomers tracked the motions of millions of stars and built a 3D map of the тёмное гало out to 160,000 light-years. Back in the day, Fritz Zwicky and Vera Rubin proved the existence of hidden mass, but its distribution remained a mystery.
The picture was stunning. The гало is not spherical, but elongated and flattened, like a deflated rugby ball. And its long axis sticks out almost perpendicular to the stellar disk — as if an invisible frame had been tilted by 90 degrees. This orientation matches the plane in which the dwarf satellite galaxies orbit.
Such a tilt is simply explained: billions of years ago, the Milky Way's disk flipped under the gravitational pressure of small galaxies. Computer simulations confirm this. The discovery ties the Standard Model to the actual behavior of galaxies and finally explains the enigmatic plane of satellites.
There is five times more dark matter than ordinary matter. Without its invisible gravity, galaxies would fly apart from centrifugal force.