Winter constellations seen in a class 4 or 5 sky

Save Dark Skies

Gauging Light Pollution: The Bortle Dark-Sky Scale

Excellent? Typical? Urban? Use this nine-step scale to rate the sky conditions at any observing site.

Celestial Objects to Observe

How to Estimate a Comet's Brightness

Comets are notorious for not following predictions, but even judging the magnitude of a bright comet that's right in front of you is not straightforward.

Celestial News & Events

A Little Comet for Southern Hemisphere Observers

Early in 2002, observers living south of the equator will have their chance to see Comet LINEAR (C/2000 WM1).