Astronomy

We know it's not made of green cheese, but what are the origins of the moon? Learn astronomers' theories about where the moon came from.

By Tracy V. Wilson

Why does the moon look so much bigger when it is near the horizon than when it is high up in the sky? This question has been pondered for hundreds if not thousands of years, and is commonly referred to as the moon illusion.

Where I live it is pretty common to see "shooting stars" -- streaks of light in the sky at night. How big is a shooting star? Do they land on earth or do they burn up? Do they land on the ground as meteorites?

The sun warms our planet every day, provides the light by which we see and is necessary for life on Earth. But what is it exactly, and what will happen when it burns itself out?

By Julia Layton & Craig Freudenrich, Ph.D.

When you look up at night and see thousands of stars, have you ever wondered what you are looking at? Learn what stars are and how they live and die!

By Craig Freudenrich, Ph.D.

The Chandler wobble is the change in the spin of Earth on its axis. Think of the wobble you see in a toy top when it first starts spinning or slows down. Its 'poles' do not spin in a perfectly straight line.

If "nature abhors a vacuum," then why doesn't the vacuum of space suck away all of the Earth's atmosphere?

It turns out that measuring the distance to a star is an interesting problem! Astronomers have come up with two different techniques to estimate how far away any given star is.

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.

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!

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

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

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