Bubble-blowing galaxies could help solve a cosmic mystery
A trio of galaxies has been caught ionizing hydrogen 680 million years after the Big Bang
![ionized hydrogen bubbles](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2020/01/010720_cc_ionizing-galaxies_feat.jpg?fit=1028%2C579&ssl=1)
Bubbles of ionized hydrogen surround three galaxies (illustrated) in the very early universe, perhaps providing a peek into how most of the hydrogen in the cosmos became ionized.
V. Tilvi et al/arXiv.org 2020, NSF’s Optical-Infrared Astronomy Research Lab, KPNO, AURA