What triggered the Big Bang

Astronomers have a good idea of how the universe has evolved since cosmic genesis. But what, if anything, came before?

Web Extra: Inside the cyclic model of the universe

Some cosmologists think the Big Bang was a single event in an infinite cycle.

Comets: Keys to the solar system’s past

After four successful missions to study comets up close, astronomers find answers to the biggest questions about the solar system’s origins.

Web Extra: Watch comets in action

Astronomers continue learning about these ancient icy wonders and have gotten near enough to capture video of these objects up close.

How Antarctica unlocks cosmic secrets

The quest to understand our universe’s earliest moments drives astronomers to Earth’s coldest continent.

Web Extra: What’s winter like in Antarctica?

A scientist who has spent six winters at the coldest continent tells us what it’s like.

All about the Helix Nebula

This planetary nebula offers more than a great view through the eyepiece. It shows astronomers how our Sun’s life will end.

Web Extra: More images of the Helix Nebula

This planetary nebula offers a great show through the eyepiece.

My time on the Hubble Space Telescope

Finding a rare type of supernova was just the beginning of this amateur astronomer’s adventure.

10 great features for Moon watchers

Our natural satellite offers plenty of targets you can spot through any size telescope.

Web Extra: There’s a lot of Moon to observe

Download PDF files, then set up your scope to view our only natural satellite.

Astronomy tests the Officina Stellare Hiper APO 130

This high-quality scope looks great, but does it produce equally terrific images?