Unusual Mountain Ahuna Mons on Asteroid Ceres

What created this unusual mountain?

Double Cluster Ngc 869 & Ngc 884

Astronomy Picture of the Day: Comet, Heart and Soul

The greenish coma of comet 21P/Giacobini-Zinner stands out at the left of this telephoto skyscape spanning over 10 degrees toward the northern constellations Cassiopeia and Perseus.

Astronomy Picture of the Day: Mars Approach

Since the distance from Earth to Mars changes drastically as the planets orbit the Sun, Mars' appearance changes dramaticaly.

Astronomy Picture of the Day: Blue Moon Tree

Does an alignment like this occur only once in a blue moon?

Astronomy Picture of the Day: Catalog Entry Number 1

Every journey has first step and every catalog a first entry

Astronomy Picture of the Day: Dual Particle Beams in Herbig-Haro 24

This might look like a double-bladed lightsaber, but these two cosmic jets actually beam outward from a newborn star in a galaxy near you

How to take Flat Frames for Astrophotography

Photographing the Night Sky

NGC 869 & NGC 884 - The Double Cluster