Mysterious microworlds

Everyone knows the Sun has nine planets. But it also has 141 moons varying from icy fragments to complex worlds with volcanoes, oceans, and atmospheres. Take a tour of the rest of the solar system.

Dark threat

Could an unseen stellar assassin cause mass extinctions on Earth?

Cosmic music man

As the universe sings, Alex Szalay listens for answers to fundamental cosmological questions.

An ice moon revealed

Cassini’s first close look at Enceladus shows Titan isn’t the only Saturn moon with an atmosphere.

Summer splendors

Set up your scope, pour a cool drink, and follow this step-by-step guide to explore the season’s best sights.

Corona light

On March 29, 2006, observers across eastern South America, northern Africa, and western Asia will be treated to a total solar eclipse.

Hale-Bopp +10

In 1995, Hale-Bopp became history’s most observed comet. Ten years later, codiscoverer Alan Hale tells its tale.


This month in Astronomy
Bob Berman’s strange universe
Glenn Chaple’s observing basics
Phil Harrington’s binocular universe

A tail’s tale

The sky this month
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