Astronomy
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.
Constellation Pictures
How to Find Orion's Belt in the Night Sky
Radio Telescope Image Gallery
How do I build a telescope at home?
Shooting the Stars as an Astrophotographer
What's the Brightest Star in the Sky? Depends on the Season
The Largest Star in the Universe Is 1,700x Bigger Than Our Sun
Twinkle, Twinkle: The Ultimate Stars Quiz
What Is a Harvest Moon?
The Mysteries of Mercury Retrograde Unveiled: A Cosmic Phenomenon
A Comprehensive Guide to the Layers of the Earth
Learn More / Page 3
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?
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?
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
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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?
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?
Precipitation does fall from the clouds of other planets, but it's a little more exotic than the rainwater we get here on Earth. Imagine sheets of methane, sulfuric acid and, yes, diamonds falling from the sky.
It's not uncommon for planets to wander alone through the universe like big, sullen teenagers. But how do they end up flying solo, and could they still harbor life?
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You might call it a Christmas miracle. Jupiter and Saturn will align so closely they may look like a double planet. The last time we saw this was in 1226.
The Quadrantids are a short but powerful meteor shower that shows up in early January. How can you glimpse it?
A magnetar is a neutron star with a super-strong magnetic field. Astronomers consider them among the scariest objects in the universe, but why?
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.
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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?
Everyone's heard of the blue moon and the harvest moon, but every other full moon of the year has a name, too. What are their names, and when do these moons occur?
Researchers at the Zwicky Transient Facility have found an asteroid in Earth's orbit. And this one has the shortest year yet.
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Did you know that a moon can leave its orbit around a large planet and go out on its own?
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.
Stars are enormous celestial bodies hot enough to register millions of degrees. They're fascinating scientific phenomena, but is it actually possible for scientists to create them?
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
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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
The European Space Agency's Gaia satellite observatory has created a 3-D model of the Milky Way - and beyond! - that charts more than a billion stars.
Say hello to the newly discovered TRAPPIST-1 system, which is just 39 light-years away and filled with seven Earth-like planets.
The rings of Saturn, Uranus and Neptune may be remnants of smaller planets destroyed long ago by the gas giants' powerful gravity.
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And solving that issue could go a long way toward making our planetary neighbor habitable.
The sun's atmosphere is actually hotter than its surface, even though you'd assume the surface is what generates all that heat. How does that work?