Magazine

Exoplanets

What is the largest star known, and how far out would its habitable zone be?

Observing

Stephen James O’Meara’s Secret Sky: Twilight musings

Robotic Spaceflight

Remembering the first solar system probes

Science

Cold weather gems photo gallery

Science

David H. Levy’s Evening Stars: Ad astra per aspera

Science

See more of Stephan’s Quintet

Observing

Bob Berman’s Strange Universe: Starry Night

Astrophotography

Tony Hallas’ Cosmic Imaging: Combining your data

Science

I read that ultraviolet light is the cause of HII regions, but this light is invisible. So why are these objects the color red?

Observing

Glenn Chaple’s Observing Basics: Feast on the winter crab

Human Spaceflight

How astronauts fixed Hubble

Solar System

At the end of the Sun’s life, when it expands into a red giant, what will become of the planets in the solar system?