Ultra-faint dwarf galaxies preserve clues to early-universe conditions, acting as cosmic fossils. Simulations show whether they formed stars or stayed dark.
When black holes tear apart stars, the wreckage heats up, creating brilliant flares. New simulations are showing these flares with more detail than ever before.
Members of the EarthSky community - including scientists, as well as science and nature writers from across the globe - weigh in on what's important to them.