Earth
Earth is our home in space. It is a big, round world. Much of it is blue water. We live on the dry land. It is a very special place. Do you like our world?
Early Reader · Change the reading level on the articleSpace articles
Read about planets, stars, galaxies and the people and tools used to explore space. Choose an article below; its reading controls let you move between the available levels.
1,134 public articles · Page 1 of 24
Astronomy
We look at the stars. We look at the moon. We look at the sun. It is all far away. It is so big! Do you like the night sky?
Early Reader · Change the reading level on the articleMoon
The Moon is in the sky. It goes around the Earth. It is very bright at night. We can see it from our homes. It helps us know the time. Do you like to look at the Moon?
Early Reader · Change the reading level on the articleSolar System
The Sun is a big star. It is in the middle. Eight planets go around it. We live on Earth. It is a very big family in space. Can you name a planet?
Early Reader · Change the reading level on the articleSun
The Sun is a big, hot star. It sits in the middle of space. It gives us light and heat. This helps us live on Earth. The Sun is very, very big. Can you feel the warm sun?
Early Reader · Change the reading level on the articleUniverse
The universe is everything. It has stars and planets. It is very, very big. It is also growing. It is a big, cool place. Can you look at the stars?
Early Reader · Change the reading level on the articleGalaxy
A galaxy is a huge group of stars. It also has dust and gas. These groups stay together in space. Our home is in one called the Milky Way. Space is very big! Can you look at the stars tonight?
Early Reader · Change the reading level on the articleMercury (planet)
Mercury is a small planet. It is near the Sun. It is made of rock. It has many holes from space rocks. This planet is very special. Do you want to see it?
Early Reader · Change the reading level on the articleMilky Way
We live in a big home. It is made of many stars. It looks like a white band in the sky. This band is our home. It is very big and pretty. Can you see it at night?
Early Reader · Change the reading level on the articleNatural satellite
Some things in space orbit a planet. We call these things moons. They follow a planet as it moves. Our Moon is one of them. It looks very pretty at night. Can you see the Moon in the sky?
Early Reader · Change the reading level on the articleNicolaus Copernicus
{ "text": "A man named Copernicus lived long ago. [IMAGE:File:Nicolaus Copernicus 1598 (116109572) (
Early Reader · Change the reading level on the articleOuter space
Space is the big area far above us. It is mostly empty. It has stars and many planets. Space helps us see far away things. It is very big and cool. Do you want to see the stars?
Early Reader · Change the reading level on the articlePlanet
A planet is a big round thing. It moves around a star. We live on a planet called Earth. It is a very special place. Do you like looking at the stars?
Early Reader · Change the reading level on the articleSpace exploration
We go to space. Robots and people go there. They use big rockets. It helps us learn new things. Space is a big place. Do you want to go?
Early Reader · Change the reading level on the articleSpaceflight
Rockets fly into space. They go very high. They can carry people or tools. This helps us learn about stars. It is a big trip! Do you want to go to space?
Early Reader · Change the reading level on the articleStar
Stars are bright lights in the sky. The Sun is our closest star. Many stars shine at night. They help us find our way. They are very far away. Do you like to look at the stars?
Early Reader · Change the reading level on the articleSupernova
A star can go boom. It is a very big blast. This blast is very bright. It can look like a new star. It helps make new stars. Can you see the bright light?
Early Reader · Change the reading level on the articleTelescope
A telescope helps us see far away. It looks at stars and planets. It can use glass or mirrors. This helps us see the sky better. It is a fun tool for us. Do you like to look at stars?
Early Reader · Change the reading level on the article3C 273
A bright light shines in space. It is far away. It is very, very bright. It is even brighter than its home galaxy. You can see it with a small tool. Can you look for it in the sky?
Early Reader · Change the reading level on the articleActive galactic nucleus
Some parts of space are very bright. They shine more than many stars. This happens near a huge black hole. The black hole pulls in gas and dust. This makes a lot of light. It is very cool to see. Can you look for…
Early Reader · Change the reading level on the articleAlpha Centauri
There are three stars close to us. They live in a group. One star is very close to our Sun. It is the closest star of all. This star helps us learn about space. Can you find it in the sky?
Early Reader · Change the reading level on the articleAndromeda Galaxy
The Andromeda Galaxy is a big group of stars. It is very close to our home. It is very bright in the night sky. You can see it with your eyes. It is a beautiful sight. Can you look for it?
Early Reader · Change the reading level on the articleApollo 11
People went to the Moon. Three men flew in a big rocket. Two men walked on the Moon. They picked up Moon rocks. They came back home to Earth. It was a big day for us! Did you see them on TV?
Early Reader · Change the reading level on the articleApollo program
People went to the Moon. They flew in big rockets. This was a long time ago. It was a big goal for our world. It helps us learn about space. Do you like the Moon?
Early Reader · Change the reading level on the articleArcturus
Arcturus is a big, red star. It is very bright in the sky. You can see it at night. It is much bigger than our Sun. It looks like a red light. Can you find it in the sky?
Early Reader · Change the reading level on the articleAsteroid belt
There is a ring of rocks in space. It sits between two planets. These rocks are all different sizes. Some are very small. Some are big. They help us learn about space. Do you like looking at the stars?
Early Reader · Change the reading level on the articleAstrometry
People look at the stars. They find where stars are. They see how stars move. This helps us know our home. It is very cool! Do you like looking at the sky?
Early Reader · Change the reading level on the articleAstronaut
An astronaut flies in space. They go in a big ship. They learn a lot of things. This helps us learn about the stars. It is very cool! Would you like to fly to space?
Early Reader · Change the reading level on the articleAstronomical coordinate systems
People use maps to find stars. These maps help us find where things are. They show us where to look in the sky. This helps us see far away things. It is like a guide for the night. Can you look at the stars tonight?
Early Reader · Change the reading level on the articleAstronomical object
Many things live in space. Some are big like stars. Some are small like rocks. They move in the dark sky. We can look up to see them. Do you like to look at the stars?
Early Reader · Change the reading level on the articleAstronomical unit
Space is very big. We use a special way to measure it. It is the distance from Earth to the Sun. This helps us know where things are. It is like a giant ruler for space. Can you imagine how far that is?
Early Reader · Change the reading level on the articleAstrophysics
We study the stars and space. Scientists look at what stars are made of. They use light to see. This helps us learn about our world. It is very cool! Do you like the stars?
Early Reader · Change the reading level on the articleAurora
The sky can glow with light. These lights look like curtains. They can be green or red. The lights happen high up in the air. They are beautiful to see. Have you seen colorful lights in the sky?
Early Reader · Change the reading level on the articleBaikonur Cosmodrome
This is a place for rockets. It is in a big, flat land. Rockets fly from here into space. This helps people visit the stars. It is a very big place. Do you like looking at the stars?
Early Reader · Change the reading level on the articleBarred spiral galaxy
Some space groups look like a bar. They have a long line of stars. This line is in the middle. Our home is in one too! It is a very big place. Can you see the stars?
Early Reader · Change the reading level on the articleBarycenter (astronomy)
Big things in space move in a circle. They move around a special spot. This spot is not a real thing. It is just a center point. It helps us see how stars and planets move. Can you find the center?
Early Reader · Change the reading level on the articleBetelgeuse
There is a big red star. It is in the sky. It looks very bright. It is much bigger than our Sun. It can be seen at night. Can you find it?
Early Reader · Change the reading level on the articleBinary star
Some stars live in pairs. They pull on each other. They spin around in a circle. This is like a dance in space. It is very cool to see. Do you like looking at the stars?
Early Reader · Change the reading level on the articleBlazar
A blazar is a bright space light. It comes from a far galaxy. A fast beam of light points at us. This makes it look very bright. It can change its light quickly. It is amazing to see! Do you like looking at stars?
Early Reader · Change the reading level on the articleBrown dwarf
Some things in space are in the middle. They are bigger than planets. But they are not big stars. They are called brown dwarfs. They give off some heat. They grow cold as they get old. Do you like looking at the stars?
Early Reader · Change the reading level on the articleCallisto (moon)
Callisto is a moon. It orbits the big planet Jupiter. It has many round holes on it. These holes come from space rocks hitting it. It is made of rock and ice. It is very far away. Do you want to see it?
Early Reader · Change the reading level on the articleCanis Major
Look up at the night sky. You can see a big dog. It is made of bright stars. One star is very bright. It is called the dog star. Can you find it?
Early Reader · Change the reading level on the articleCanopus
Canopus is a very bright star. It looks white in the sky. It is a giant star. It is much bigger than our Sun. This star helps people find their way. Can you see it at night?
Early Reader · Change the reading level on the articleCapella
Capella is a very bright star. It is in the night sky. It looks like one star. But it is actually four stars! They stay close together. It is a beautiful sight. Can you find it?
Early Reader · Change the reading level on the articleCarina Nebula
The Carina Nebula is a big cloud in space. It has many bright stars. Some stars are very, very big. These stars make lots of light. It is a beautiful sight. Do you like looking at the stars?
Early Reader · Change the reading level on the articleCaroline Herschel
Caroline was a star finder. She looked at the night sky. She found many bright comets. This work was very special. She was the first woman to do this. Do you like to look at stars?
Early Reader · Change the reading level on the articleCassiopeia (constellation)
Look up at the night sky. You can find a shape like a big letter W. It is made of bright stars. This shape is called Cassiopeia. It is very easy to see. Can you find the W in the sky?
Early Reader · Change the reading level on the articleCelestial mechanics
Stars and planets move in space. They pull on each other. This pull makes them move. It helps us know where they go. We can see them in the sky. Do you like to look at the stars?
Early Reader · Change the reading level on the article