Planets for kids starts with the 8 planets in order from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, which you can remember with “My Very Energetic Monkey Just Swung Under Noodles.”
This guide to planets for kids is for parents and children ages 5 to 12 to read together. Every number comes from NASA, rounded to kid-friendly sizes, with the NASA source named so curious kids can check it.
Inside: a fact table for all 8 planets, a tour of each one, why Pluto is a dwarf planet, how planets formed, which planets you can see with your own eyes, scale models with the math worked out, jokes and a quiz.
Key Takeaways
There are 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
The inner four are small and rocky; the outer four are gas giants and ice giants.
Pluto became a dwarf planet in 2006 because it has not cleared its path around the Sun.
NASA says five planets are visible without a telescope: Mercury, Venus, Mars, Jupiter and Saturn.
A hallway or toilet paper scale model shows kids how spread out the planets really are.
Table of Contents
The 8 Planets in Order (and a Mnemonic to Remember Them)
Quick Answer
There are 8 planets in our solar system. In order from the Sun they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. To remember the order, try: My Very Energetic Monkey Just Swung Under Noodles.
NASA splits the planets into two teams. The inner planets (Mercury, Venus, Earth and Mars) are rocky worlds with solid ground. The outer planets are giants: Jupiter and Saturn are gas giants, and Uranus and Neptune are ice giants, with swirling gases above a core instead of a hard surface to land on.
Each word in our mnemonic starts with the same letter as a planet. Even better, ask your child to invent their own silly sentence: kids remember the ones they make up.
Planets for Kids: Fact Table for All 8 Planets
Every number here comes from NASA’s Planetary Fact Sheet (last updated March 2025, checked November 2026), rounded for kids and converted to miles and Fahrenheit. “One day” means sunrise to sunrise.
Planet
Width (about)
Average distance from the Sun
One day
One year
Moons (NASA count)
Average temperature
Mercury
3,000 miles
36 million miles
About 176 Earth days
88 Earth days
0
333°F
Venus
7,500 miles
67 million miles
About 117 Earth days
225 Earth days
0
867°F
Earth
7,900 miles
93 million miles
24 hours
365 days
1
59°F
Mars
4,200 miles
142 million miles
About 24.7 hours
687 Earth days
2
-85°F
Jupiter
88,800 miles
484 million miles
About 10 hours
About 12 Earth years
95
-166°F
Saturn
74,900 miles
890 million miles
About 10.7 hours
About 29 Earth years
274
-220°F
Uranus
31,800 miles
1.8 billion miles
About 17 hours
About 84 Earth years
28
-319°F
Neptune
30,800 miles
2.8 billion miles
About 16 hours
About 164 Earth years
16
-328°F
The 8 planets compared, rounded from NASA’s Planetary Fact Sheet (checked November 2026).
About moon counts: astronomers keep finding small new moons, so these numbers change. NASA’s Saturn page says Saturn had 274 confirmed moons as of March 2025, with more waiting for official confirmation. Checking NASA’s pages together to see if the count has grown is a fun habit for number-loving kids.
The Inner Planets: Mercury, Venus, Earth and Mars
Mercury: The smallest planet and the closest to the Sun. Its year is only 88 Earth days, but it spins so slowly that one sunrise to the next takes about 176 Earth days: a single Mercury day lasts two Mercury years.
Venus: The hottest planet, averaging about 867°F even though Mercury is closer to the Sun. NASA’s fact sheet shows its air pressure is about 92 times Earth’s, a thick blanket of atmosphere. Venus spins backward compared with most planets, and one spin takes about 243 Earth days, longer than its 225-day year.
Earth: The third planet from the Sun, the fifth largest, and the only planet with exactly one moon.
Mars: The Red Planet. NASA says it looks reddish because iron in its rocks has rusted. If Earth were a nickel, Mars would be about the size of a raspberry. It has the largest volcano in the solar system, Olympus Mons, more than 25 miles tall, and two small moons, Phobos and Deimos, named after the horses that pulled the chariot of the Greek god of war.
Hungry for more? Our fun facts for kids collection has dozens of space, animal and body facts.
Big days go better with a good night of sleep.
Got a little one at home too? Our free two-minute quiz builds a gentle, personalized sleep plan for babies and toddlers.
The Outer Planets: Jupiter, Saturn, Uranus and Neptune
Past Mars and the asteroid belt are the four giants. All four have rings, many moons and freezing temperatures.
Jupiter: The biggest planet, about 11 times wider than Earth, and the fastest spinner, with a day of about 10 hours. It has about 318 times Earth’s mass, so you would weigh more than twice as much there.
Saturn: Famous for rings that NASA says are made of billions of chunks of ice and rock. They stretch up to 175,000 miles from the planet, yet the main rings are typically only about 30 feet thick. Saturn is the only planet less dense than water: NASA says it could float in a bathtub, if one that big existed.
Uranus: Tipped on its side. NASA’s fact sheet gives its tilt as about 98 degrees (Earth’s is about 23), so it rolls around the Sun like a ball instead of spinning like a top.
Neptune: The farthest and coldest planet on average, about 2.8 billion miles from the Sun and about -328°F. One trip around the Sun takes about 164 Earth years.
Why “ice giants”? NASA puts Uranus and Neptune in their own group, separate from the much bigger gas giants: each is only about 4 times wider than Earth. Sorting things into groups is a skill kids practice in our science experiments for kids too.
Why Is Pluto a Dwarf Planet?
From its discovery in 1930 until 2006, Pluto was called the ninth planet. In 2006 the International Astronomical Union (IAU), the group of astronomers that sorts and names space objects, agreed on a definition of a planet, which NASA says cut the count from nine to eight. A planet must:
Orbit the Sun.
Be big enough that its gravity pulls it into a round shape.
Clear its path around the Sun of other objects.
Pluto passes the first two tests but not the third: NASA explains that other objects cross its orbital path. That makes it a dwarf planet. NASA says Pluto is about 1/5 the width of Earth, takes 248 years to circle the Sun and has five known moons. In 2015 the New Horizons spacecraft flew past and photographed a giant heart-shaped patch on its surface. Should Pluto be a planet again? It makes a great family debate.
The Sun and the Other Dwarf Planets
The Sun is a star, not a planet. NASA says it gathered more than 99% of the material in the solar system when everything formed. NASA officially recognizes five dwarf planets:
Ceres: The largest object in the asteroid belt and the only dwarf planet in the inner solar system.
Pluto: In the Kuiper Belt, a ring of icy bodies beyond Neptune.
Haumea: Oval shaped and one of the fastest-spinning large objects in the solar system.
Makemake: Slightly smaller than Pluto.
Eris: Its discovery pushed astronomers to define what a planet is.
Many planets, moons and stars are named after old myths; our space names list explains where dozens of them come from.
How Did the Planets Form?
NASA says our solar system formed about 4.6 billion years ago from a huge cloud of gas and dust. In kid-sized steps:
The cloud collapsed, possibly nudged by the shock wave of a nearby exploding star.
It flattened into a spinning disk, like pizza dough twirled in the air.
Most of the material fell to the center and became the Sun.
Farther out, dust and gas stuck together into bigger and bigger clumps. Some grew into planets, dwarf planets and large moons.
Leftovers that never became a planet formed the asteroid belt.
How to See Planets in the Night Sky
NASA says five planets are visible without a telescope or binoculars: Mercury, Venus, Mars, Jupiter and Saturn. Uranus is very faint and NASA recommends a telescope; Neptune always needs one. NASA’s tips:
Look along a line: The planets orbit in a flat plane, so they always appear along the same line or arc across the sky. Find one, then look along that path for others.
Look up, not low: Planets are easiest to see about 10 degrees or more above the horizon, away from trees and buildings, and hard to find low in a still-glowing twilight sky.
Check tonight’s sky: Which planets are up changes month to month, so use a sky chart or stargazing app on the night you go out.
Bring a blanket, let your eyes adjust to the dark, and keep it short for little ones. Never look at the Sun, and never point binoculars or a telescope near it.
Hands-On Planet Activities for Kids
1. Hallway or toilet paper distance model. Earth’s average distance from the Sun is called one astronomical unit (AU). Put a ball for the Sun at one end of a long hallway and place a sticky note for each planet, or unroll toilet paper and count squares. Distances are worked out from NASA’s fact sheet, and the math is double-checked.
Planet
Distance in AU (about)
Hallway (1 AU = 1 foot)
Toilet paper (1 AU = 2 squares)
Mercury
0.4
About 5 inches
Just under 1 square
Venus
0.7
About 8 1/2 inches
About 1 1/2 squares
Earth
1
12 inches
2 squares
Mars
1.5
18 inches
3 squares
Jupiter
5.2
About 5 feet 2 inches
About 10 1/2 squares
Saturn
9.6
About 9 feet 7 inches
About 19 squares
Uranus
19.2
About 19 feet 2 inches
About 38 squares
Neptune
30.2
About 30 feet 2 inches
About 60 squares
Scale distance model, worked out from NASA Planetary Fact Sheet distances.
Kids are always surprised by how crowded the inner four are and how empty space gets past Jupiter.
2. Paper planets to scale (Earth = 1 inch wide). From NASA’s diameters, cut circles: Mercury about 3/8 inch, Venus just under 1 inch, Earth 1 inch, Mars about 1/2 inch, Jupiter about 11 1/4 inches, Saturn about 9 1/2 inches, Uranus about 4 inches and Neptune about 3 7/8 inches.
3. Your weight on other planets. Multiply your weight by a planet’s gravity from NASA’s fact sheet and divide by Earth’s 9.8. A 60-pound child would weigh about 23 pounds on Mercury or Mars, 54 on Venus, 55 on Saturn, 53 on Uranus, 67 on Neptune and 141 on Jupiter.
4. Planet crafts. Paint a paper plate Saturn with a cardboard ring, or hang painted paper balls from a hanger in planet order. Our easy crafts for kids guide has supply lists; skip small beads with kids who still mouth things.
Planet Jokes and a Quick Quiz
We wrote these jokes ourselves:
Why does Saturn never lose at hula hoop? It has rings to spare.
Why did Neptune pack a sweater? It lives 2.8 billion miles from the nearest heater.
Why does Uranus win every rolling race? It already spins on its side.
Why did Pluto start a club? To hang out with the other dwarf planets.
Quiz: 1. Which planet is closest to the Sun? 2. Which is hottest? 3. Which is biggest? 4. Which could float in a giant bathtub? 5. Which spins on its side? 6. How many planets can you see without a telescope? 7. Where is Olympus Mons? 8. When did Pluto become a dwarf planet?
Preschoolers (3 to 5): Stick to names, colors and sizes. Sort balls from big (Jupiter) to tiny (Mercury) and chant the planet names. One or two facts at a time is plenty.
Ages 6 to 8: Learn the order with a mnemonic, build the hallway model and try the paper planets. This age loves extremes: hottest, coldest, biggest, most moons.
Ages 9 to 12: Bring in numbers and debate. Let them check the fact table against NASA, calculate their weight on each planet and argue Pluto’s case.
At every age, “Let’s look it up” is a great answer: it shows that scientists learn by checking. For rainy-day space time, browse our indoor activities for kids.
Planets for kids can be simple: eight planets, four rocky and four giant, from Mercury out to Neptune. Start with the order and a silly mnemonic, add a few wow facts (Venus is hottest, Saturn could float, Uranus rolls on its side), then make it hands-on with a hallway model or a night under the stars. Since moon counts keep changing, teach kids to check NASA’s own pages.
Frequently Asked Questions
What are the 8 planets in order?
From closest to the Sun to farthest, the 8 planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A silly sentence such as My Very Energetic Monkey Just Swung Under Noodles helps kids remember the order. The first four are rocky inner planets; the other four are giants.
How do you explain planets for kids?
Explain that planets are big, round worlds that travel around the Sun, and Earth is one of eight. Start with names and order, compare sizes with balls or fruit, then add wow facts, like Saturn being light enough to float. Hands-on models and spotting planets at night make it stick.
Why is Pluto not a planet anymore?
In 2006 the International Astronomical Union agreed that a planet must orbit the Sun, be round, and clear its path of other objects. Pluto is round and orbits the Sun, but NASA explains that other objects cross its path. So Pluto is now a dwarf planet, along with Ceres, Haumea, Makemake and Eris.
Which planet has the most moons?
Saturn. NASA’s Saturn page says it had 274 confirmed moons as of March 2025, and NASA’s fact sheet lists 95 for Jupiter. Astronomers keep discovering small new moons, and some wait years for official confirmation, so these numbers can change.
What is the hottest planet?
Venus, with an average temperature of about 867 degrees Fahrenheit on NASA’s fact sheet, even though Mercury is closer to the Sun. Venus has a very thick atmosphere, with surface pressure about 92 times Earth’s, while Mercury has almost none. That surprises most kids.
Which planets can you see without a telescope?
NASA says five planets are visible without binoculars or a telescope: Mercury, Venus, Mars, Jupiter and Saturn. They appear along the same line across the sky and are easiest to spot well above the horizon. Uranus is very faint, and Neptune always needs a telescope.
Gentle changes, peaceful nights.
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