What if string theory is wrong?

If it is, then dark matter, dark energy, and cosmic inflation are in big trouble.

Mars like you’ve never seen it

The first color images from the Mars Reconnaissance Orbiter’s high-resolution camera show details not much bigger than a bread box.

What makes Mira tick?

Changes in this star”s complex atmosphere power its pulsations.

How astronomers glimpse the naked galaxy

By observing in infrared wavelengths, astronomers peer through obscuring dust and reveal the Milky Way”s spiral structure.

Online extra: Infrared scavenger hunt

Enjoy a dozen more great images from Spitzer.

When planets stray

Wayward worlds unleash a rain of ruin in their neighborhoods.

Online extra: A solar-system fairy tale

Once upon a time, two giants roughed up the neighborhood.

Explore winter’s 12 best star clusters

These must-see stellar treats look their best in winter’s crisp, clear air.

Online extra: Enjoy more star clusters

Here”s a mini photo album of winter”s best.

Big bang for your astronomy bucks

A few dollars can add value to your observing kit.

Simple steps to save the night sky

Light pollution is a growing problem, but you can help curtail it.

Online extra: Meet the Night Sky Team

Rangers work to preserve the dark night skies above our national parks.

Get the most from CCD images

CCD cameras are revolutionizing astroimaging, enabling amateurs to capture more detail than ever.

Celestron’s SkyScout

No telescope? No problem. Just pull out this handheld device, and you’ll be identifying stars in no time.


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

The hunter becomes the hunted

The sky this month
New products
Book reviews
Coming events
Advertiser index
Reader gallery