Astronomy is a broad discipline covering all facets of astrophysics. In this section you can learn about the origins of the universe, black holes and other astronomical phenomena.
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?
As every fledgling and seasoned astronomer knows, groups of stars that form some sort of arrangement are known as constellations. Peer at some of the most famous constellations that humans use to navigate, divine the future and tell stories.
Radio telescopes can give us some impressive insights into the universe. This collection of pictures highlights some of the images these telescopes have captured.
Some of the most amazing star making regions in space are highlighted in this collection of nebula pictures. Check out some stunning pictures nebulae in this gallery.
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?
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?
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.
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?
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?
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?
Hundred of meteors fly across the sky every night, but only a few make it to Earth. Meteors are best known for the brilliant streaks of light they make as they burn up in the atmosphere. Learn about 10 memorable meteor crashes that left an impression.
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.
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.
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.
Jupiter is the largest planet and is fifth from the sun. It is the third-brightest spot in our skies--after the sun and Venus. Jupiter is made up almost entirely of gas, which means it doesn't have a solid surface like Earth does.
The smallest and most-distant planet in our solar system is tiny, icy Pluto. It is even smaller than our moon, and wasn't discovered until 1930 — the only planet discovered in the twentieth century.
Mercury is the closest planet to the sun, and it is the second smallest. It is the fastest-moving planet, so it was named after the Roman god of speed. Like Earth, it is a terrestrial planet, meaning it has a solid surface that you could land on.
Our planet Earth is part of a solar system that consists of nine (and possibly ten) planets orbiting a giant, fiery star we call the sun. For thousands of years, astronomers studying the solar system have noticed that these planets march across the sky in a predictable way.
Neptune is the eighth planet from the sun, the fourth largest, and a gas planet. It is named after the Roman god of the sea. Neptune is four times the size of Earth, and its day lasts a little more than16 hours. Its year is about 165 Earth years. Neptune's orbit is a perfect circle. The last stop on spacecraft Voyager's epic trip through the solar system was the gas giant Neptune.
Uranus is the seventh planet from the sun, and is named for the ancient Greek deity of the Heavens, the earliest supreme god. It is the third largest planet in the solar system, and is three times as large as Earth.
Venus is the second planet from the sun, and is about the same size as Earth. It is a terrestrial planet, meaning it has a solid surface. But the harsh conditions on Venus make it very inhospitable. Two spacecraft, Pioneer Venus 1 and Magellan, were able to penetrate the thick atmosphere of this planet.
Saturn is the sixth planet from the sun and the second largest planet in the solar system. It is named for the Roman god of agriculture, one of the most important gods in the Roman world. Saturn is made mostly of hydrogen and helium, and its poles appear to be flattened because of its speedy rotation on its axis...
Saturn is the sixth planet from the sun and the second largest planet in the solar system. It is named for the Roman god of agriculture, one of the most important gods in the Roman world.
Mars, which is the fourth planet from the sun and the third smallest in size, got its name because of its rusty red color. People associated the planet's blood-red color with war, so they named it Mars, after the Roman god of war.
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!