Xiang-Xiang Xue

Using the motions of millions of stars, astronomers have built a 3D map of the dark halo. Its shape is not a sphere, but an elongated, flattened cloud. Surprisingly, the halo's long axis is almost perpendicular to the stellar disk. This orientation hints at a possible 'flip' of the disk in the past

Data from the Gaia satellite allowed a double check of gravity: how stars rotate and how they oscillate up and down. No modified gravity variant could explain both motions at once. But the invisible dark matter cloud handled it effortlessly. This is a strong argument that dark matter is real, and Ei