Sprite Lightning in HD

This phenomenon occurs in the sky over our heads, not the sea.

The Horsehead Nebula

The Horsehead Nebula is one of the most famous nebulae on the sky.

Eye Sky a Dragon

What do you see when you look into this sky?

IC 1805: The Heart Nebula

What energizes the Heart Nebula?

The Moon and Jupiter over the Alps

What are those bright lights in the sky ahead?

Animation: Spiral Disk around a Black Hole

What would it look like to orbit a black hole?

Human as Spaceship

You are a spaceship soaring through the universe.

IC 1795: The Fishhead Nebula

To some, this nebula looks like the head of a fish.

Milky Way over Pyramid of the Feathered Serpent

To see the feathered serpent descend the Mayan pyramid requires exquisite timing

Astronomy Picture of the Day: Good Morning Leonid

On November 17, just an hour before sunrise, this bright and colorful meteor flashed through clear predawn skies.