149 Years Ago Today, a Foggy Washington Sky Nearly Cost Us a Discovery

On the night of August 17, 1877, at the U.S. Naval Observatory in Washington, D.C., an astronomer named Asaph Hall was ready to give...

What Is a Constellation? A Beginner’s Guide to the Sky’s 88 Star Patterns

A constellation is a group of stars that forms a recognizable pattern in the night sky, one we've given a name, usually after a mythological figure, animal, or object. There are 88 of them officially recognized, and together they map out the entire sky....

How Many Planets Are There? The Real Answer Is Bigger Than Eight

There are eight planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn,...

What Is a Galaxy? A Simple Guide to the Great Islands of Stars

A galaxy is an enormous collection of stars, gas, dust, and dark matter, all...

The Leo Constellation: How to Spot the Lion of the Spring Sky and Its Bright Star Regulus

Most constellations take a generous imagination to see. Someone tells you a random scattering...

The Big Dipper: How to Find the Sky’s Most Famous Star Pattern and Use It to Find North

Almost everyone has spotted the Big Dipper at some point, even people who swear...

How Far Is the Sun From Earth? The 93-Million-Mile Answer and Why It Keeps Changing

The Sun sits an average of about 93 million miles (150 million kilometers) from...

How Old Is the Universe? The 13.8-Billion-Year Answer and How We Measured It

The universe is about 13.8 billion years old. More precisely, 13.787 billion years, give...

What Is the Milky Way Galaxy? Everything You Need to Know

Have you ever looked up at a clear night sky and wondered about our place in the vast cosmic ocean? Our home, a massive...

What Is Dark Matter? The Invisible Stuff Holding the Universe Together

Theres something genuinely strange sitting at the heart of modern astronomy, scientists are confident...

When Will the Earth End: The Science Behind Our Planet’s Distant Future

The Short Answer The Earth isn't ending any time soon. There's no scientifically predicted doomsday...

How Many Planets Are There? The Real Answer Is Bigger Than Eight

There are eight planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn,...

Galaxies & Deep Space

Supermoon: What It Really Is, Why It Happens, and When to Catch the Next One

A supermoon is a full moon that lines up with the Moon's closest approach...

What Is a Constellation? A Beginner’s Guide to the Sky’s 88 Star Patterns

A constellation is a group of stars that forms a recognizable pattern in the...

How Many Planets Are There? The Real Answer Is Bigger Than Eight

There are eight planets in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn,...

What Is a Galaxy? A Simple Guide to the Great Islands of Stars

A galaxy is an enormous collection of stars, gas, dust, and dark matter, all...

How Far Is the Sun From Earth? The 93-Million-Mile Answer and Why It Keeps Changing

The Sun sits an average of about 93 million miles (150 million kilometers) from...

A Half-Built Telescope Was Just Being Tested. It Found Something Nobody Had Ever Seen.

In November 2025, a team in Chile pointed a telescope that wasn't even finished...

What Is Uranus’s Distance from the Sun? The Complete Guide to the Ice Giant’s Orbit

When you look up at the night sky Uranus is totally invisible to the...

What Sort of Star Is the Sun? Facts, Size, and Fate of Our Blazing Star

Weve all grown up staring at it, feeling its heat, and building our entire...

How Do Black Holes Form: The Violent Death That Gives Birth to the Universe’s Darkest Objects

There's a star in the Andromeda galaxy that simply vanished. Astronomers had been watching...

Astronomers Discover the Nearest Black Hole to Earth

Black holes have a reputation for being distant, exotic objects, the kind of thing...

Cassini Has Been Gone for Eight Years. It’s Still Making Discoveries.

Cassini deliberately burned up in Saturn's atmosphere back in September 2017, ending its mission...

How Long Does It Take to Get to the Moon: From a Few Hours to Over a Year

The Short Answer For the crewed Apollo missions, the trip to the Moon took about...

What Is the Mid-Atlantic Ridge?

There is a massive mountain range running through the Atlantic Ocean that most people...

How Long Is a Light-Year? The Cosmic Yardstick That Measures Distance, Not Time

Say the phrase "a light-year away" out loud and it sounds like a stretch...

Planets

What Is the Fermi Paradox? Where Is Everybody?

In 1950, physicist Enrico Fermi was having lunch with colleagues at Los Alamos, chatting about recent UFO reports, when he reportedly blurted out a question that's haunted scientists ever since: "But where is everybody?" With billions of stars and likely billions of habitable planets...

What Is a Nebula? The Cosmic Clouds That Build and Bury Stars

Some of the most breathtaking photos in all of astronomy, the ones that end...

How Far Is the Moon From Earth: The Real Distance and Why It Keeps Changing

The Short Answer On average, the Moon sits about 384,400 kilometres from Earth, which is...

How Many Moons Does Jupiter Have Latest Count 2024

I remember looking through a telescope in my backyard as a kid. I felt...

Where Did the Term “Right Ascension” Originate, and Why Not Just Call It “Ascension”?

If you've ever tried picking up a telescope, downloading a stargazing app, or looking...

Space Missions

How Are Stars Born The Life Cycle of a Star Explained

Did you know nearly every atom in your body came from massive, burning furnaces in space? It's a humbling fact that links us to...

Something in Cygnus Is Flinging Particles to Energies We Can Barely Comprehend, and Nobody’s Sure What

Stretched across roughly six degrees of sky, about the width of twelve full Moons...

How Far Is the Sun From Earth? The 93-Million-Mile Answer and Why It Keeps Changing

The Sun sits an average of about 93 million miles (150 million kilometers) from...

The Big Dipper: How to Find the Sky’s Most Famous Star Pattern and Everything It Points To

Ask almost anyone to name a shape in the night sky and there's a good chance they'll say the Big Dipper. It's the one pattern nearly everybody knows, the seven bright stars shaped like a saucepan or a ladle that hang over the northern...

What Is a Galaxy? A Simple Guide to the Great Islands of Stars

A galaxy is an enormous collection of stars, gas, dust, and dark matter, all bound together by gravity into a single system. Our own...

Planet Earth

What Is Dark Matter? A Friendly Guide to the Mystery

Ever thought about the space between stars? Is it really empty, or is something...

How Many Moons Does Uranus Have: The Ice Giant’s Cast of Literary Worlds

The Short Answer Uranus has 29 known moons. That count only recently ticked up, when...

Why Do Stars Twinkle: The Simple Reason Behind the Night Sky’s Shimmer

The Short Answer Stars twinkle because of the Earth's atmosphere, not because of anything the...

Sirius, the Dog Star: The Brightest Light in Our Night Sky and the Tiny Ghost Beside It

On a clear winter night, step outside and look toward the south. There is...

Why Does Saturn Have Rings? The Science Behind Its Stunning Appearance

"Somewhere, something incredible is waiting to be known," Carl Sagan once said. Looking at our solar system, Saturn's rings capture our imagination like nothing else. They have puzzled us for centuries, making us wonder about our cosmic home. People often wonder: why does saturn have...

All Articles

NASA’s Artemis Program What’s Happening in 2026 Explained

"Exploration is in our nature. We began as wanderers, and we are wanderers still."...

How Do Astronauts Sleep in Space Explained Simply

Did you know astronauts see 16 sunrises and sunsets every day? This fast pace...

What Is a Nebula? The Birthplace of Stars Explained

Have you ever looked up at the night sky and wondered where our sun...

Why Does Uranus Rotate on Its Side Learn the Science Behind It

Ever thought a planet could just tip over? Our solar system looks like a...

What Can You See in the Night Sky Without a Telescope Tonight

Many people think you need expensive gear to explore space. Friends often say they...

How to Start Stargazing: A Complete Beginner’s Guide

Looking up at the night sky brings a peace that's hard to find. The...