Orion Arm
We live in a big part of space. It is like a long arm. Our home is in this arm. It has many bright stars. It is named after a group of stars. Can you find the stars in the sky?
Early Reader · Change the reading level on the articleSpace articles — Page 18
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 18 of 24
Orion's Belt
Look at the night sky. You can see three bright stars. They sit in a straight line. They look like a belt. These stars help us find our way. Do you see them too?
Early Reader · Change the reading level on the articlePair-instability supernova
Some stars are very big. They can blow up in a huge flash. This happens when the star gets too heavy. It falls in on itself. Then it pops! The star is gone. Have you seen a bright star?
Early Reader · Change the reading level on the articlePale Blue Dot
A space probe took a photo. It is far away in space. Our home looks like a tiny dot. It is a pale blue color. This helps us see our world. It is a very special view. Can you see the tiny dot?
Early Reader · Change the reading level on the articleParticle horizon
Light travels from far away. It takes a long time. We can only see so far. This is like a line in space. The line grows every day. The world is very big. Can you see the stars?
Early Reader · Change the reading level on the articlePatrick Moore
Patrick Moore loved the stars. He looked at the Moon. He wrote many books about space. He was on TV for a long time. He helped us see the sky. Do you like to look at stars?
Early Reader · Change the reading level on the articlePavo (constellation)
Pavo is a group of stars. It looks like a bird. The bird is a peacock. It is in the southern sky. You can see its bright stars. Do you like birds?
Early Reader · Change the reading level on the articlePeculiar galaxy
Some star groups look strange. They have odd shapes. This happens when they bump into each other. They can even make many new stars. These groups look blue in the dark sky. They help us learn about space. Do you like…
Early Reader · Change the reading level on the articlePeggy Whitson
Peggy Whitson is an astronaut. She flies high in space. She spent many days up there. She even led the space station. She is a real hero to us. Do you want to fly to space too?
Early Reader · Change the reading level on the articlePerseus Arm
Our home is in a big group of stars. It has long arms that curve. One arm is named after a star group. It is very far away from us. We can look up to see it. Do you like to look at the stars?
Early Reader · Change the reading level on the articlePerseus Cluster
A big group of stars lives far away. It is a huge home for many galaxies. This group is very heavy. It has hot gas inside it. It even makes a sound. You cannot hear it, though. Can you imagine a sound in space?
Early Reader · Change the reading level on the articlePerseus (constellation)
Perseus is a group of stars. It is high in the sky. You can see it in the spring. It looks like a hero from a story. It is very bright. Can you find it in the night sky?
Early Reader · Change the reading level on the articlePerseverance (rover)
A robot lives on Mars. It drives on red rocks. It looks for tiny life from long ago. It even makes the air we breathe! This helps us learn about space. Do you want to visit Mars?
Early Reader · Change the reading level on the articlePerturbation theory
Math can help us solve hard problems. We start with a simple problem. Then we add a tiny change. This helps us find a close answer. It helps us know where things go. Can you find a small change?
Early Reader · Change the reading level on the articlePete Conrad
Pete Conrad was a brave pilot. He flew high in space. He was one of the first to walk on the Moon. This was a big job! He helped fix a space home too. Do you like space?
Early Reader · Change the reading level on the articlePhạm Tuân
Pham Tuan was a pilot. He flew planes in the sky. He even went to space! He went far up in a rocket. He looked at the Earth from above. He is a hero. Would you like to fly to space?
Early Reader · Change the reading level on the articlePhobos (moon)
Phobos is a moon of Mars. It is a small rock. It moves very fast in the sky. It looks like it rises in the west. This moon is very special. Do you want to see it?
Early Reader · Change the reading level on the articlePhoenix (constellation)
Phoenix is a group of stars. It looks like a bird. You can find it in the south sky. It is part of the Southern Birds. It is a beautiful sight. Can you see it?
Early Reader · Change the reading level on the articlePhotometric system
Stars have many colors. Scientists use tools to see them. These tools help us see light. They show us how stars look. It helps us learn about space. Do you like looking at stars?
Early Reader · Change the reading level on the articlePhoton epoch
Long ago, the world was very hot. It was full of bright light. This light helped make the first bits of matter. It helped make the things we see today. The world was not clear yet. Can you imagine a world of light?
Early Reader · Change the reading level on the articlePhotosphere
The sun has a bright skin. This skin sends out light. It looks like it is boiling. Hot parts rise up and cool parts fall down. This light helps us see. It is very bright! Can you feel the sun's heat?
Early Reader · Change the reading level on the articlePictor
Pictor is a group of stars. It looks like a painter's tool. It is far away in the sky. We can see it from the south. It is a pretty sight. Do you like to look at stars?
Early Reader · Change the reading level on the articlePillars of Creation
Big clouds of gas sit in space. These clouds make new stars. They look like tall towers. The stars grow inside the clouds. This is how stars are born. It is a beautiful sight. Can you see the stars?
Early Reader · Change the reading level on the articlePioneer 10
A space probe went to Jupiter. It was the first to go there. It took many pictures. It helped us learn about space. It was a big trip! Do you like stars?
Early Reader · Change the reading level on the articlePioneer 11
A space probe went far away. It flew past big planets. It saw the rings of Saturn. This helps us learn about space. It was a brave little tool. Do you like stars?
Early Reader · Change the reading level on the articlePioneer program
People sent machines into space. These machines were called Pioneer. They flew to the Moon. They also flew to far planets. Some even left our home area. They carry a gold sign for others to find. Do you like looking…
Early Reader · Change the reading level on the articlePi Puppis
A star shines bright in the night sky. It looks orange to our eyes. This star is very big. It is much bigger than our Sun. You can see it at night. It is a pretty sight. Do you like to look at stars?
Early Reader · Change the reading level on the articlePisces–Cetus Supercluster Complex
The sky has many star groups. These groups are very big. They are part of a huge chain. We live in one small part. It is a very long path. Can you look up at the stars?
Early Reader · Change the reading level on the articlePisces (constellation)
Pisces is a group of stars. It looks like two fish. They are tied with a cord. It is high in the sky. We can look for it at night. Can you find the fish?
Early Reader · Change the reading level on the articlePiscis Austrinus
Look at the stars. They make a big fish. It is a fish in the sky. One star is very bright. It is the 18th brightest star. Can you find it?
Early Reader · Change the reading level on the articlePlanetarium
A planetarium is a special room. It has a big round roof. It shows you the stars and planets. It makes the night sky look real. You can see space from your seat. Do you want to see the stars?
Early Reader · Change the reading level on the articlePlanetary core
A core is the center of a planet. It can be hard or liquid. It is very deep inside. It helps make the planet warm. We cannot reach it. Can you imagine a giant ball of metal inside our home?
Early Reader · Change the reading level on the articlePlanetary differentiation
The Earth has many layers. Heavy parts sink down deep. Light parts float up high. This makes the ground we walk on. It helps us know our world. Do you like to explore?
Early Reader · Change the reading level on the articlePlanetary habitability
Some places in space could have life. They might have water. They might have heat too. This helps things grow. We look for these places. Do you want to find them?
Early Reader · Change the reading level on the articlePlanetary mass
Space has many big things. Planets are very heavy. We cannot weigh them on a scale. We look at how they move. This tells us how big they are. Do you like looking at the stars?
Early Reader · Change the reading level on the articlePlanetary nebula luminosity function
Stars can leave glowing clouds behind. We look at these clouds in space. They help us see how far away galaxies are. This helps us learn about our big world. It is like a map for space. Can you look at the stars?
Early Reader · Change the reading level on the articlePlanetary science
People study the stars and space. They look at moons and planets. They learn how they were made. This helps us know our home. It is very fun to learn. Do you like the stars?
Early Reader · Change the reading level on the articlePlanetesimal
Space has many small rocks. They are like tiny bits of planets. These rocks stick together to grow big. They help us learn about space. They are like little time capsules. Can you imagine a rock from long ago?
Early Reader · Change the reading level on the articlePlanet Nine
Some people think a big world is out there. It stays far away in the dark. We cannot see it yet. It might help us learn more. It is a big mystery. Do you think it is there?
Early Reader · Change the reading level on the articlePlanets beyond Neptune
People look for far planets. They look way past Neptune. They found Pluto long ago. Now they look for more. It is a big hunt! Do you like the stars?
Early Reader · Change the reading level on the articlePolarization in astronomy
Light can move in special ways. It can travel in lines. Dust in space can change light. This helps us see far away. It helps us learn about stars. We can see things far in space. Can you look at the stars?
Early Reader · Change the reading level on the articlePolar orbit
Some things fly high in space. They go over the top of the Earth. They go over the bottom too. This helps us see the whole world. It helps us watch the weather. Can you look up at the sky?
Early Reader · Change the reading level on the articlePollux (star)
Pollux is a bright star. It looks orange in the sky. This star is very big. It is much larger than our Sun. It is a giant star. Can you find it at night?
Early Reader · Change the reading level on the articlePosition angle
Stars can look like pairs. We use a special way to find them. It tells us where one star is. It shows how far it is from North. This helps us see the sky. Do you like to look at stars?
Early Reader · Change the reading level on the articlePre-main-sequence star
A star starts small. It grows from gas and dust. The star gets hot and tight. It makes its own light. This helps make new worlds. It is a big wonder. Do you like the stars?
Early Reader · Change the reading level on the articlePre-stellar core
New stars start in dark clouds. These clouds are made of dust and gas. The dust pulls together in a tight group. This group will soon become a star. It is like a tiny star nursery. Can you see the stars in the sky?
Early Reader · Change the reading level on the articlePrimordial fluctuations
A long time ago, space was not smooth. It had tiny bumps. These bumps grew into stars and worlds. They are like seeds for everything. We see them in the sky. Do you see the stars?
Early Reader · Change the reading level on the articleProject Gemini
People flew a ship to space. It was called Gemini. Two people sat inside the ship. They practiced how to fly to the Moon. This helped us learn more about space. Can you imagine flying in a ship?
Early Reader · Change the reading level on the article