Bob Berman’s guide to cosmic rays

This energetic flow of particles surrounds us, but what effect does it really have?

The exoplanet next door

There’s no star closer to us than Proxima Centauri — and now we know it has an Earth-mass planet in its habitable zone.

Ask Astro

The Sky This Month

StarDome and Path of the Planets

Sizing up space rocks

From near-Earth objects to the distant Oort Cloud, the solar system’s bodies teach us about its origins.

What links galaxies and black holes?

Most large galaxies harbor a supermassive black hole in their core. Astronomers are studying how these monsters affect their host’s evolution.

Meet astronomy’s West Coast wizards

By specializing in lenses, mirrors, and drives, three California companies have risen to the top.

How astronomers measure brightness

Whose bright idea was this backward magnitude system anyway?