Aaron J. Romanowsky

A runaway supermassive black hole leaves a superheated gas tail visible from Earth. The James Webb Space Telescope clocked its escape velocity at 954 km/s, revealing that such giants can be flung from their galaxies.

Stretching around NGC 1052 is a chain of ultra-diffuse dwarfs — galaxies almost devoid of dark matter. According to the 'bullet dwarf' hypothesis, they were born from a head-on collision of gas clouds: dark matter slipped through, while the stars lined up in a row. Skeptics saw a projection illusion