Hi! I'm Cosmo the Astronaut! 🧑‍🚀

Are you ready for the most amazing trip ever? We're going to fly through outer space and visit every single planet in our Solar System!

We'll meet a giant ball of fire, a planet covered in storms, a beautiful blue planet (that's our home!), and so much more!

Put on your space helmet 🪖, buckle up your seatbelt, and get ready to blast off in 3... 2... 1...!

👉 Tap on things throughout the book to discover secrets!

Our Solar System is like a giant family! In the middle is our Sun — a huge, blazing star — and all the planets travel around it in big circles called orbits.

There are 8 planets in our Solar System. From closest to farthest from the Sun they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

The Sun's gravity (like an invisible pulling force) keeps everything in place — just like how a yo-yo swings around your finger!

Our Solar System is incredibly big. It would take 6 months to fly to Mars in a rocket!

The Sun is a giant ball of burning, glowing gas — it's actually a star, just like the tiny dots you see in the night sky!

The Sun gives us two super important things: light 💡 and warmth 🔥. Without the Sun, Earth would be freezing cold and dark — no plants, no animals, no us!

The Sun is so enormously huge that you could fit 1,000,000 Earths inside it. That's one MILLION!

The surface of the Sun is about 5,500°C — that's 90 times hotter than your oven at home! 🌡️

Mercury is the smallest planet in our Solar System and the closest one to the Sun!

Mercury is very speedy — it zooms around the Sun in just 88 Earth days. That means one year on Mercury is only 88 days long — less than 3 months!

Mercury has no air (no atmosphere), so it has no wind or weather. During the day it gets boiling hot (430°C!) and at night it becomes super cold (−180°C).

Mercury is covered in craters — big round dents from space rocks that crashed into it billions of years ago! 🪨

Venus is the hottest planet in the Solar System — even hotter than Mercury! Its temperature reaches a scorching 465°C. That's hot enough to melt lead!

Venus is wrapped in thick, yellow clouds made of acid. These clouds trap all the Sun's heat like a blanket — this is called the greenhouse effect.

Here's a weird thing: Venus spins backwards! So on Venus, the Sun rises in the West and sets in the East — opposite to our Earth!

Venus is the brightest object in our night sky after the Moon. People call it the "Evening Star"! ⭐

Welcome home! Earth is our amazing planet — the only place in the entire universe we know for sure has life on it!

Earth is just the right distance from the Sun — not too hot, not too cold. Scientists call this the "Goldilocks Zone" 🐻!

About 71% of Earth is covered in water — that's why it looks blue from space! We have oceans, rivers, lakes, rain and snow.

Earth has one Moon 🌕 that orbits around us. The Moon's gravity causes our ocean tides!

Earth takes 365 days to go around the Sun — that's one year! 🎂

Mars is called the Red Planet because its soil is full of rusty iron — just like old nails that turn red! 🔴

Mars has the biggest volcano in the entire Solar System — Olympus Mons! It's 3 times taller than Mount Everest, the tallest mountain on Earth!

Mars has 2 tiny moons named Phobos and Deimos — those mean "Fear" and "Dread" in Greek!

Scientists have sent robots called rovers 🤖 to drive around Mars and take photos. Someday, humans might visit Mars!

A day on Mars is almost the same as Earth — just 24 hours 37 minutes!

Between Mars and Jupiter lies the Asteroid Belt — a giant ring of millions of rocky chunks floating in space!

Asteroids are like leftover building blocks from when the Solar System was formed. Jupiter's strong gravity stopped them from joining together to make a planet.

Most asteroids are quite small — like rocks and pebbles. But some are enormous! The biggest one is called Ceres and it's so big it's classified as a dwarf planet!

Don't worry — our spaceship has a force field! 🛡️ Let's zoom through carefully...

Fun fact: Space movies always show asteroids very close together, but in real life there's lots of space between them!

Jupiter is the BIGGEST planet in our Solar System — so big that all the other planets could fit inside it with room to spare!

Jupiter is a gas giant — it doesn't have a solid surface to stand on. It's made entirely of swirling gases!

The most famous feature of Jupiter is the Great Red Spot — a massive storm that has been raging for over 350 years! That storm is bigger than the entire Earth!

Jupiter has at least 95 moons 🌕 — that's the most moons of any planet! Its biggest moon, Ganymede, is bigger than the planet Mercury!

Saturn is famous for its stunning rings — the most beautiful sight in the Solar System! These rings are made of billions of pieces of ice and rock, ranging from tiny pebbles to huge boulders.

Saturn is also a gas giant like Jupiter, made mostly of hydrogen gas. It's so light that if you had a bathtub big enough, Saturn would float on water!

Saturn has 146 moons — the most of any planet! Its biggest moon, Titan, even has its own thick atmosphere and lakes — but the lakes are made of liquid gas, not water!

Saturn is so far away that it takes 29 Earth years to go around the Sun once!

Uranus is an ice giant — it's not made of regular gas like Jupiter or Saturn, but of a slushy mix of ice and water!

Uranus is beautiful blue-green colour because of a gas called methane in its atmosphere. Methane absorbs red light and reflects blue-green light!

The most amazing thing about Uranus is that it rolls on its side! It's tilted at 98 degrees — almost completely sideways! Scientists think a huge space rock crashed into it long ago and knocked it over! 😲

Uranus has 27 moons, and they're all named after characters from Shakespeare's plays and Alexander Pope's poems! 📚

Neptune is the farthest planet from the Sun — so far that sunlight takes 4 hours to reach it! On Earth, sunlight takes just 8 minutes.

Neptune has the strongest winds in the Solar System — up to 2,100 km/h! That's 6 times faster than the strongest hurricanes on Earth! 🌪️

Neptune is a deep, beautiful dark blue colour. Like Uranus, methane gas gives it that colour.

One year on Neptune lasts 165 Earth years! When Neptune was discovered in 1846, it hasn't even completed one full orbit around the Sun until 2011!

You may have heard of Pluto! It used to be the 9th planet, but in 2006, scientists decided it was too small to be a proper planet.

Now Pluto is called a dwarf planet — like a mini-planet! It's smaller than our Moon!

Pluto is very, very far away — so far that when NASA sent a spacecraft (New Horizons) to visit it, the trip took 9.5 years!

When New Horizons reached Pluto in 2015, it took amazing photos — and we saw that Pluto has a huge heart-shaped ❤️ region on its surface! How cute!

Even though it's not a full planet, we still love Pluto! 💜