Adam Moss

An old star like the Sun, at the end of its life, shrinks into a white dwarf — a dense sphere about the size of Earth. After that, it simply cools down, like embers in a campfire. But some white dwarfs somehow stay hot for billions of years. Astronomers studied such objects within a radius of one hundred parsecs from us and found an unexpected pattern.

Dark matter is the great invisible. It governs the motion of galaxies and bends light, creating gravitational lenses. Einstein predicted this effect, Zwicky was the first to suspect hidden mass in clusters, and Rubin proved its presence from the speeds of stars.

Almost a century after Фриц Цвикки suspected something was amiss in the motion of galaxies in the Coma cluster, and Вера Рубин measured stellar velocities in spiral arms, the nature of тёмной материи remains one of the most vexing mysteries.