How life survived a cool early Sun

How did Earth’s surface stay warm enough for liquid water to exist and life to emerge?

Web Extra: Brewing up a solar storm

Earth and the life on it managed to survive a faint Sun during the solar system’s early years. We face a far more luminous star in the 21st century, and one that is nearing maximum activity during 2013.

Why the universe has no center

Confused by the universe’s size, shape, and limits? Let our experts clarify these complex concepts.

Web Extra: Why cosmic expansion is speeding up

What’s the mysterious “stuff” that causes this acceleration?

The science behind UFOs

Even the strangest sightings have logical explanations.

Web Extra: More UFOs identified

Although some UFOs are truly bizarre, they still can have explanations that do not involve aliens.

Target Hubble’s galaxy classes

How do astronomers classify galaxies? Find out by observing the various types.

Dennis Mammana’s cosmic portraits

This night sky photographer blends the terrestrial with the celestial.

Web Extra: More celestial images from a night sky photographer

Dennis Mammana captures the color, motion, and majesty of the heavens in ways one rarely sees.

How to choose the right binoculars

When the time comes to observe with both eyes open, follow these tips and you won’t go wrong.

Explore 11 spring binocular gems

Grab your binoculars and peruse a globular cluster, double stars, and lots of galaxies.

Web Extra: 10 more great spring binocular sights

When the weather begins to warm, get your sky-fix by grabbing your binoculars.

“Astronomy” tests the Telescope Drive Master

This easy-to-use device will smooth out your mount’s tracking to make your images crystal clear.

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