NEW! Follow our sweeping history of the telescope from Galileo's first look at the stars to the work of modern observatories.

Discover the fierce force of gravity and pelt poor Jupiter with a comet!

NASA needs your help in planning a Hubble Servicing Mission. Join the team! (Replaces "Astronaut Challenge.")

Statistically speaking, this cosmic photo shoot is out of this world!

Whip up a batch of comets — without trashing the kitchen!

Great balls of fire … er, ice! Explore comet facts and fantasies through the ages.

Galaxy construction timeline: billions of years. For you: ten minutes.

Take the plunge! Fall into one of our universe’s eeriest phenomena.

UPDATED to reflect current science!
Keep the planets in your pocket. A fun card game tours our cosmic neighborhood.

Catch the (light) wave! Find out how color can be more than meets the eye.

Galactic census takers needed — no experience or door-knocking required.