Astronomy

A ball of fire blazed through southern Peru and left a huge crater -- and then villagers started getting sick. Early reports said the groundwater boiled and the air filled with sulfur. What happened?

By Jacob Silverman

A look at the night sky at any time of year will reveal a faint band of light stretching across the sky -- our solar system's home, the Milky Way. How much do we really know about it?

By Craig Freudenrich, Ph.D. & Desiree Bowie

Jupiter is the largest planet in the solar system. Big as this gas giant is though, next to the sun, it's still small.

By Mark Mancini

Mercury is the closest planet to the sun, and it's the smallest in the solar system. So why does it have longer days than we have on Earth?

By Mark Mancini

While we generally picture the sun and planets when thinking about our solar system, it also consists of comets, asteroids and hundreds of moons.

By Nicole Antonio

Neptune is the eighth planet from the sun and one of the coldest. It also has supersonic winds that are the fastest in the solar system.

By Mark Mancini

Uranus is the seventh planet from the sun and sits on an axial plane tilted at a jaw-dropping 97.7-degree angle. And yes, Uranus does actually stink.

By Mark Mancini

The atmospheric pressure is crushingly extreme on Venus, and lead would melt into a puddle on its surface. But as hellish as this place sounds, it actually has a lot in common with Earth.

By Mark Mancini

Saturn is the sixth planet from the sun and the second-largest planet in the solar system. This gas giant has more rings and moons than any other planet.

By Mark Mancini

Some of the most interesting objects in our solar system are also the smallest or largest. In addition to the sun, planets, and moons, our solar system has a variety of small objects such as asteroids, comets, stars, meteors, and moons. These have affected what has happened on Earth in many ways.

If I was on the moon and the earth was black (no lights were on) and a flashlight was turned on facing the moon, would I see the light? If I couldn't, would there be any way to detect any residual matter that came from the light on Earth or does light die after a certain distance?

Even though it's tiny compared to the rest of the universe, Earth is a complex planet that, so far, is the only one we know of that sustains life.

By Kathryn Whitbourne & Mark Mancini

There are all kinds of telescopes, but you can make a simple one on your own. You'll need a few basic supplies and this step-by-step article. Get ready to star-gaze!

Exoplanets, planets beyond our solar system, have been found in their thousands in the last two decades. Before that, we barely knew about the variety in outer space.

By Kathryn Whitbourne

A dying star can explode with the force of a few octillion nuclear bombs and create any element in the universe. But why do stars go supernova?

By Laurie L. Dove

It's tough to wrap your mind around a time when the Earth wasn't here. So how do Earth and the rest of the planets out there get their start in the universe?

By Robert Lamb

We can't defy the odds of an asteroid taking a turn for Earth forever, so the world's astronomers watch the sky. What happens once they spot something?

By Robert Lamb

You know Saturn and Venus and Mars. Can you put the eight planets of the solar system in the correct order? There are several ways to do this.

By Valerie Stimac

In recent years, Saturn has overtaken Jupiter as the planet with the most moons in our solar system. How many does it have and could it have even more?

By Valerie Stimac & Desiree Bowie

Arcturus is 113 times brighter than our sun, even though it's only a little bigger. What else should we know about this red giant?

By Valerie Stimac

Surely you've watched tons of sunsets in your lifetime. But have you ever seen the sunset and the moonrise simultaneously? Is that even possible?

By Sharise Cunningham

Scientists have observed flashes of X-rays coming from behind a supermassive black hole, consistent with Albert Einstein's prediction that extremely large objects can bend light.

By Patrick J. Kiger

The Mars solar conjunction occurs every two years and forces NASA to stop communicating with assets on the Red Planet. So what's the deal?

By Sharise Cunningham

Early dark energy, a form of dark energy that may have existed a few hundred thousand years after the big bang, could help clarify the universe's rate of expansion. But its existence hasn't been proven.

By Patrick J. Kiger

Check out this video of what astronauts in space see as the shadow of the moon crosses our planet.

By Christopher Hassiotis