Lan Zhang

The Milky Way's stellar disk is like a glowing pinwheel, and тёмное вещество 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.

A galaxy is like a cosmic highway where stars, like cars, race along circular orbits. Their speed is set by the invisible "cargo" of mass enclosed within the orbit: the more massive the central region, the faster the stars at the periphery.

A regular radar works like an amateur photographer: it takes a series of blurry snapshots and tries to stitch them into a panorama. Details are smeared, and in a long corridor or crowd, the robot easily gets lost. The principle is simple: like a bat, the radar emits a wave and catches the echo.