March 2009

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The world's best-selling astronomy magazine offers you the most exciting, visually stunning, and timely coverage of the heavens above. Each monthly issue includes expert science reporting, vivid color photography, complete sky coverage, spot-on observing tips, informative telescope reviews, and much more! All this in an easy-to-understand, user-friendly style that's perfect for astronomers at any level.

Features

Is there something we don't know about gravity?

By John D. Anderson

Spacecraft flybys and the Moon's orbit aren't following predictions. Whatever is causing this could usher in a new theory of gravity.

pg. 22

Web extra: What can't be causing the gravity anomalies

By Liz Kruesi

Scientists rule out some explanations for these strange occurrences.

Surprises from MESSENGER's historic Mercury flyby

By Richard Talcott

The MESSENGER spacecraft flew past Mercury in October, revealing landscapes never seen up close before.

pg. 28

Web extra: Message from Mercury

By Richard Talcott

The MESSENGER spacecraft flew past the innermost planet October 6, giving scientists their second close look at Mercury in 2008.

Cassini flies through Enceladus' geysers

By Richard Talcott

The Cassini spacecraft flew past Saturn's moon Enceladus twice in October, diving into its water-rich plume and imaging its dynamic surface.

pg. 32

Web extra: Inside Saturn's erupting moon

By Richard Talcott

The Cassini spacecraft flew past Enceladus once in August and twice in October, returning some of the sharpest images of the active moon yet.

How the Spitzer Space Telescope unveils the unseen cosmos

By Michael Werner

NASA's flagship infrared eye in the sky has probed hidden corners of the universe for 5 years. Spitzer chief scientist Michael Werner shares some of the telescope's greatest discoveries.

pg. 44

Web extra: Explore the Spitzer Space Telescope's greatest scientific hits

By Daniel Pendick

The structure of star-forming regions, the recipe of a grand design spiral galaxy, and the look of the Milky Way's center all made the list.

Discover galaxy groups and clusters

By Steve Coe

With an 8-inch or larger scope and a dark sky, go after these distant citizens of the cosmos.

pg. 52

Web extra: More galaxy groups to observe

By Michael E. Bakich

Add another 10 to the list from "Discover galaxy groups and clusters."

How to build a backyard observatory