Magazine

Alien Life, Science

Bob Berman’s strange universe: Ask the aliens

Human Spaceflight

Does the debris left behind by comets pose a hazard to the International Space Station?

Observing

Glenn Chaple’s observing basics: See double tonight

Science

High on Mars and the Moon

Observing

Phil Harrington’s binocular universe: Take a small tour of the Big Dog

Solar System

Why is the Sun’s corona so hot?

Exoplanets

What is the difference between a planetesimal and a dwarf planet?

Observing

Stephen James O’Meara’s secret sky: Orion’s phantom loop, part 2

Cosmology

Does the Hubble constant change over time?

Science

The vintage observatory: thriving in the 21st century

Science

Ask Astro web extra: What is the difference between an asteroid and comet?

Cosmology

Can cosmic microwaves “see” extra dimensions?