The active galactic nucleus is powered by a supermassive black hole and was spotted just 670 million years after the Big Bang, making it the most distant quasar ever discovered.
Molecular oxygen is a key component of the air humans breathe, and now astronomers have spotted it a half-billion light years away. But don't hold your breath for quasar whippets.
Thanks to gravitational lensing, astronomers can observe normal stars across colossal stretches of space and time.
Dark energy is driving the accelerating expansion of the universe. No one knows what it is.