The Solar System

Can the curvature of the Earth only be seen from outer space? If you didn't know that the Earth is a sphere, there are three common observations you could use to convince yourself that it is.

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?

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.

The occasional sunspot can interrupt communications here on Earth. But major solar flares have the potential to cause more havoc. Could a flare-up wipe out all our electronics?

By Jonathan Strickland

Scientists have discovered the existence of water on both our moon and on Mars. Both findings are significant, but what do they mean? Can we use this information to our advantage for space exploration?

By Josh Briggs

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

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

The changing phases of the moon have given us an enduring curiosity about the dark side of the moon. But is there really a dark side of the moon? What would we see there?

By Jonathan Strickland

The moon is often the largest object in the sky outside of the sun. What is the moon made of, how did it form -- and why do people blame it for their strange behavior?

By Craig Freudenrich, Ph.D.

Asteroid belts aren't quite the dense fields of gigantic spinning rocks that you may have seen in a "Star Wars" film, but they're still fascinating. In fact, the main asteroid belt may tell us how our entire solar system came into existence.

By John Fuller

You've probably heard that staring at the sun is bad - even a few seconds can damage your eyes. But what if you looked at a solar eclipse?

By Katherine Neer & Yves Jeffcoat

Since the 1960s, we've been captivated by the planet Mars. How different is our neighbor, and what have we learned about the most explored planet?

By Craig Freudenrich, Ph.D., Nicholas Gerbis & Mark Mancini

A total solar eclipse is a rare event that can be an amazing thing to witness. Learn about solar eclipses and how to observe one safely.

By Craig Freudenrich, Ph.D.

Pluto is relatively round and orbits the Sun. So, why doesn't it qualify as a planet?

By Patrick J. Kiger & Kathryn Whitbourne

After Viking 1 captured images of what looked like a face on Mars, the public began to speculate. Had Martians carved a colossus, or was there another answer?

By Stephanie Watson

The only thing that's lurking in the shadows during a lunar eclipse is the moon. When Earth's shadow blocks sunlight from directly illuminating a full moon, you're witnessing a lunar eclipse.

By Jessika Toothman

Although other planets have rings, none are as spectacular as Saturn's. What makes the planet's stratified rings, and how did they get there in the first place?

By Stephanie Watson

Until recently, most people assumed that if Mars had liquid water, it no longer did and hadn't for quite some time. But scientists have recently noticed some anomalies in photos of Mars that may suggest there is water. Could there be life, too?

By Sarah Dowdey & Robert Lamb