11 Amazing Space Facts for Kids [UPDATED Facts]

Zooming a toy rocket ship across the living room usually leads to some very big questions about how far up the sky really goes. Once your child starts pointing at the bright Moon right before bedtime, their curiosity about stars and planets never seems to stop.

Pairing their favorite astronaut toys with a few true stories about our solar system turns those bedtime mysteries into a fun space adventure you can share together.

11 Interesting & Fun Space Facts for Kids They Will Love to Know about

When you were a kid, you probably looked up at the night sky and wondered how those tiny bright dots stayed up there without falling down. Even grown-ups get surprised when they hear how strange the Sun, the Moon, and the eight planets really are.

Now let us take a look at those fun space facts!

1. The Sun Is a Colossal Star That Could Hold Over One Million Earths

When you look up in the daytime, the Sun looks about the size of a dinner plate in the sky. That is only because it sits about 93 million miles away from Earth.

Compared to all the stars across the universe, astronomers classify our Sun as a medium-sized yellow dwarf star. But compared to our planets, our Sun is colossal! It is 109 times wider than Earth. If the Sun were a hollow ball, over one million Earths could fit inside it.

On a giant scale, the Sun weighs 330,000 times as much as Earth and holds 99.8% of all the material in our solar system. Picture a big beach ball next to a tiny pea to see how big our star really is.

2. Mercury Is Closest to the Sun, Yet Venus Is Actually Hotter

You might think Mercury is the hottest planet because it sits closest to the Sun. Daytime on Mercury reaches 800 degrees Fahrenheit, yet it has almost no air to trap that warmth, so nighttime drops to minus 300 degrees Fahrenheit.

Venus is actually the hottest planet in our solar system, even though it is the second planet from the Sun. Venus is wrapped in a thick blanket of carbon dioxide gas and clouds that traps heat inside.

Just like pulling a thick winter blanket over your head keeps your warmth inside, Venus’s thick air traps the Sun’s heat all day and night. That trapped heat makes Venus hot enough to melt metal like lead into puddles of liquid.

3. One Full Spin on Venus Takes Longer Than Its Trip Around the Sun

Here on Earth, our planet spins around once every 24 hours to give us one day and one night. Venus turns so slowly that its clock feels completely backward!

One full 360-degree spin on Venus takes 243 Earth days, while its whole trip around the Sun (its year) takes only 225 Earth days. That means Venus takes longer to complete one spin on its axis than it does to travel all the way around the Sun!

Here is the coolest twist: Venus also spins backward compared to Earth. Because it spins backward while moving forward around the Sun, the Sun rises in the west and sets in the east every 117 Earth days. So while its spin is super slow, a sunrise-to-sunset day on Venus actually lasts about half of its year!

4. Space Is Completely Silent Because There Is No Air to Carry Sound

When you watch space movies with your kid, rockets and lasers make loud booms as they zoom past each other. In real life, outer space is completely silent.

Sound waves need air, water, or solid ground to travel through. Sound waves cannot travel through the empty vacuum of space because there is no air between the stars and planets.

Sound moves like a row of dominoes knocking into each other to carry noise to your ears. Since empty space has no air dominoes to pass the sound along, astronauts use radios inside their helmets to talk to each other.

5. Jupiter Is the Biggest Planet and Has a Storm Bigger Than Earth

While our Sun is the largest overall object in the solar system, Jupiter is the undisputed king of all the planets! This huge gas giant is about 11 times wider than Earth and weighs more than twice as much as all the other planets combined.

Jupiter is so big that even its famous storm, called the Great Red Spot, is bigger than our entire planet Earth. That one giant storm has been spinning in Jupiter’s clouds for more than 300 years.

If Jupiter were the size of a basketball, Earth would look like a little grape sitting right inside that red storm.

6. Mars Has a Giant Volcano That Is Nearly Three Times as Tall as Mount Everest

Mars is a cold, rocky desert planet that is only about half the width of Earth. Even though Mars is smaller than Earth, its dead volcanoes grew much taller than any mountain here at home.

Mars is home to Olympus Mons, the largest volcano in our solar system. Measured from bottom to top, this giant volcano stands 26 kilometers (about 16 miles) high.

That makes Olympus Mons nearly three times as tall as Mount Everest, which rises 29,032 feet above the ocean on Earth. Stacking two Mount Everests on top of each other still would not reach the top of Olympus Mons, you would need nearly three!

7. Saturn Is Made of Light Gas, So It Could Float in Water

Saturn is the second-largest planet in our solar system and is about nine times wider than Earth. When you see something that huge, you would expect it to sink like a heavy rock.

Instead of heavy rock, Saturn is made mostly of light gases like hydrogen and helium. That gives Saturn the lowest density of any planet in our solar system at about 70 percent that of water.

Just like a big beach ball floats in a pool while a small pebble sinks, Saturn is lighter for its size than water. If you had a bathtub or ocean big enough to hold it, Saturn would float right on top.

8. Astronaut Tracks on the Moon Stay Preserved for Millions of Years

When your kid presses footprints into wet sand at the beach, wind and waves wash those tracks away in a few minutes. Stepping onto the Moon works very differently.

The Moon has no air, wind, or rain to blow or wash its dusty gray soil away. Because nothing sweeps the ground clean, boot prints and rover tracks stay pressed into the Moon soil for millions of years.

Cameras on NASA’s Lunar Reconnaissance Orbiter spacecraft even took pictures of the exact tracks that Apollo 15 astronauts made 39 years earlier! Unless hit by tiny space dust over tens of millions of years, those first footprints will stay preserved for generations. You can share the story of those first Moon walks with your child through books about the Moon landing.

9. Uranus Is the Only Planet That Spins on Its Side Like a Rolling Ball

Almost every planet in our solar system spins upright like a toy top turning on a table. Uranus, an icy blue planet about four times wider than Earth, does something completely different.

Uranus is the only planet that spins on its side, turning in the opposite direction of Earth and most other planets. One full sideways spin on Uranus takes 17 hours and 14 minutes.

Instead of spinning like an upright top, Uranus looks like a playground ball rolling sideways across the floor as it travels around the Sun.

10. Saturn Travels With an Enormous Family of Over 274 Moons

When you look up at bedtime, you see just one Moon over Earth, and inner planets like Mercury and Venus have zero moons at all. Out where the giant gas planets orbit, moons gather in huge crowds.

Saturn has the biggest moon family in our solar system with over 274 confirmed moons (and recent discoveries have brought that total up to 293 moons!). Because Saturn is so big, its strong gravity can hold onto hundreds of icy and rocky moons at once.

If Earth is like a parent holding hands with one child at the park, Saturn is like a teacher watching hundreds of kids on a giant field trip all at the same time.

11. Sunlight Takes About 8 Minutes and 20 Seconds to Reach Your Backyard

When you flip a wall switch in your bedroom, the lamp lights up right away. Sunlight has to travel a much longer road before it warms your backyard.

Even though light is the fastest thing in the universe, the Sun sits about 93 million miles away from Earth, which is 400 times farther than the Moon. Because of that huge distance, sunlight takes about 8 minutes and 20 seconds to reach us.

That sunshine warming your kid’s face at the park left the Sun more than 8 minutes ago, about the time it takes to eat a bowl of cereal! For more bedtime curiosity, check out these science and nature facts together.

Frequently Asked Questions (FAQs)

How many planets are in our solar system?
Our solar system has eight official planets, which are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, along with five officially recognized dwarf planets.

Which is the biggest and smallest planet in our solar system?
While the Sun is the largest overall object at the center of our solar system, Jupiter is the biggest planet at about 11 times wider than Earth, and Mercury is the smallest planet at a little more than one-third the width of Earth.

Why is Venus hotter than Mercury?
Venus is hotter than Mercury because Venus has a thick blanket of carbon dioxide gas and clouds that traps heat inside, while Mercury has almost no air to hold onto the Sun’s heat at night.

How old is our Sun?
Our Sun is a yellow dwarf star that is about 4.5 billion years old and sits right in the middle of its lifecycle.

Which planet has the shortest day in the solar system?
Jupiter has the shortest day of any planet, spinning all the way around once in just 10 hours.

Can people breathe the air on Mars?
People cannot breathe on Mars without a spacesuit because Mars has a very thin air layer made mostly of carbon dioxide, nitrogen, and argon instead of the oxygen we breathe on Earth.

For a long time, you might have thought Mercury was the hottest planet or that outer space was full of loud rocket booms. Learning how our solar system really works makes sharing bedtime stories with your kid a lot more fun.

That was it, folks! Hope you and your little one enjoyed these amazing facts about space.