Here in our Universe, stars shine brightly, providing light and heat to planets, moons, and more. But some objects get even hotter, by far.

Our Universe isn’t just expanding, the expansion is accelerating. Instead of dark energy, could a “lumpy” Universe be at fault?

A recent measurement has simultaneously settled an ongoing scientific debate while puzzling scientists.

On larger and larger scales, many of the same structures we see at small ones repeat themselves. Do we live in a fractal Universe?

Forget billions and billions. When it comes to the number of galaxies in the Universe, both theorists’ and observers’ estimates are too low.