Have you ever looked up at the night sky and wondered what is really out there? Learning about planets for kids has never been more exciting.
Our solar system is filled with giant storms, icy rings, scorching heat, and mysteries scientists are still trying to solve.
From the tiniest rocky planet to a gas giant hundreds of times bigger than Earth, each planet has its own incredible story waiting to be found.
How Many Planets Are in the Solar System?
There are 8 planets in our solar system. In 2006, Pluto was reclassified as a dwarf planet, leaving eight official planets.
They’re split into two groups. The two groups are
- The inner planets: Mercury, Venus, Earth, and Mars, are rocky and closer to the Sun.
- The outer planets: Jupiter, Saturn, Uranus, and Neptune, are much larger and made mostly of gas or ice.
Pro Tip: To remember the order, try: “My Very Educated Mother Just Served Us Nachos.”
All 8 Planets for Kids: Facts & Guide
Our solar system has eight amazing planets, each with its own unique features, size, and secrets waiting to be found.
1. Mercury
The smallest planet and closest to the Sun, Mercury completes a full orbit in just 88 Earth days with no atmosphere to regulate its extreme temperatures.
Fun Fact: You’d celebrate a birthday every 88 days on Mercury, that’s over 4 birthdays a year!
2. Venus
Venus is the hottest planet (~460°C) thanks to its thick atmosphere, which traps heat, and it spins in the opposite direction to most planets.
Fun Fact: A single day on Venus is actually longer than its entire year!
3. Earth
Earth is the third planet from the Sun, the only known planet with life, and sits perfectly in the “Goldilocks Zone” with 70% of its surface covered in water.
Fun Fact: Earth is the densest planet in the entire solar system!
4. Mars
Known as the Red Planet, Mars gets its reddish color from iron in its soil and is home to Olympus Mons, the solar system’s largest volcano at 27 km tall.
Fun Fact: Mars hosts Valles Marineris, the longest valley in the entire solar system!
5. Jupiter
Jupiter is the largest planet, so massive that over 300 Earths could fit inside it, and it has 80+ moons, including Ganymede, which is larger than Mercury.
Fun Fact: Jupiter’s Great Red Spot is a storm that has been raging for hundreds of years!
6. Saturn
Saturn is the second-largest planet, instantly recognized by its stunning rings made of ice and rock, and is light enough to float in water.
Fun Fact: Saturn’s rings are as wide as 22 Earths side by side but only about 30 feet thick!
7. Uranus
Uranus is the coldest planet, at around 225°C, and orbits the Sun on its side, with its axis tilted at an extreme 97 degrees.
Fun Fact: Uranus literally rolls around the Sun instead of spinning upright like the other planets!
8. Neptune
Neptune is the farthest planet from the Sun, glows bright blue due to methane in its atmosphere, and takes 165 Earth years to complete just one orbit.
Fun Fact: Neptune was discovered in 1846 and has only finished its very first orbit since discovery in 2011!
Fun Facts About the Solar System
The solar system is full of surprises that even adults find hard to believe. Here are some of the coolest fun facts about the solar system that will blow your mind!
- The Sun accounts for 99.9% of the mass of our entire solar system, making everything else tiny by comparison.
- Saturn is so light for its size that it would actually float if you dropped it into a giant bathtub full of water.
- Jupiter has over 80 moons, including Ganymede, which is larger than the planet Mercury.
- Halley’s Comet swings past Earth roughly every 76 years, last seen in 1986 and due back around 2061.
- Five planets, including Mercury, Venus, Mars, Jupiter, and Saturn, can be spotted with the naked eye on a clear night.
- Earth is the only planet in our solar system that is not named after a Roman or Greek god.
- Ice exists across multiple planets and moons in the solar system, not just in Earth’s cold places.
- Our solar system is approximately 4.6 billion years old and formed from a giant spinning cloud of gas and dust.
Inner Planets vs. Outer Planets: What’s the Difference?
Not all planets are the same. Our solar system is divided into two groups based on location, size, and what they are made of.
| Feature | Inner Planets | Outer Planets |
|---|---|---|
| Planets | Mercury, Venus, Earth, Mars | Jupiter, Saturn, Uranus, Neptune |
| Also called | Terrestrial / Rocky Planets | Gas Giants / Ice Giants |
| Size | Smaller | Much larger |
| Surface | Solid rocky surface | No solid surface (gas/ice) |
| Moons | 0–2 moons | Dozens of moons each |
| Location | Closer to the Sun | Beyond the asteroid belt |
What About Pluto: Is Pluto Still a Planet
Pluto was reclassified as a dwarf planet in 2006 by the International Astronomical Union because, to be a full planet, a body must clear its orbit, which Pluto does not meet.
It now belongs to a group that includes dwarf planets like Eris, Haumea, Makemake, and Ceres. Interestingly,
NASA’s New Horizons probe visited Pluto in 2015 and discovered a stunning heart-shaped region on its surface!
How to Remember All 8 Planets in Order
Learning the planet order is easy with the right trick. Use this simple mnemonic, and you will never forget the eight planets again!
- The mnemonic “My Very Educated Mother Just Served Us Nachos” stands for Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune in order.
- Each first letter matches a planet, making it one of the easiest memory tricks for kids to learn and remember.
- Try drawing each planet in order from the Sun, using different colors to make each one unique and recognizable.
- Color and label each planet as you draw it, adding fun details like Saturn’s rings or Jupiter’s Great Red Spot.
- Repeating the mnemonic while drawing helps lock the order into memory through both visual and verbal learning.
How to Remember All 8 Planets in Order
Learning the planet order is easy with the right trick. Use this simple mnemonic, and you will never forget the eight planets again!
- The mnemonic “My Very Educated Mother Just Served Us Nachos” stands for Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune in order.
- Each first letter matches a planet, making it one of the easiest memory tricks for kids to learn and remember.
- Try drawing each planet in order from the Sun, using different colors to make each one unique and recognizable.
- Color and label each planet as you draw it, adding fun details like Saturn’s rings or Jupiter’s Great Red Spot.
- Repeating the mnemonic while drawing helps lock the order into memory through both visual and verbal learning.
Wrapping It Up
The universe is far bigger than eight planets, but understanding planets for kids is the perfect first step into the world of space science.
Each planet offers clues about solar system formation and beyond. Keep asking questions, stargazing, and exploring.
Grab a notebook, sketch the planets in order, and who knows, the next big space discovery might just start with a curious mind like yours.
