Cosmology | Page 2 of 23 | Astronomy.com

10 modern mysteries of the universe

The expanding universe

How can the visible universe be 46 billion light-years in radius when the universe is only 13.8 billion years old?

The mystery of dark energy: This Week in Astronomy with Dave Eicher

Cosmology, Science

How large is the universe? This Week in Astronomy with Dave Eicher

The Euclid image of the Horsehead Nebula, an iconic target for backyard astrophotographers and space telescopes alike. Credit: ESA.

Cosmology, Galaxies, Science, Stars

Euclid telescope releases first awe-inspiring images in dark universe hunt

An animation from the FLAMINGO simulation.

Watch the universe evolve in the most comprehensive simulation ever

A frame from the Illustris Simulation

What is the cosmic web made of?

Interested in space? Here are the degrees you can get in astronomy

How vast is the universe? Unimaginably enormous

Time is not an absolute.

Exclusive book excerpt: The Universal Timekeepers

Giant cosmic bubble of galaxies thought to be relic from early universe

The Big Freeze: How the universe will die