Welcome to Planet Earth: Our Amazing Home

Have you ever stopped to think about where you live? Not your house or your apartment or even your city—I'm talking about your REAL home. The one that holds everything: your house, your school, every park you've ever played in, every swimming pool you've ever splashed in, and every single tree you've ever climbed. Your real home is so big that if you rode in an airplane for days and days, you still wouldn't reach the edge of it! Your real home is our amazing planet Earth, and guess what? It's also home to billions of other people, millions of animals, and trillions of plants that all share this incredible place with you. Earth is the only planet we know of in the entire universe that has life—and you're one of the lucky ones who gets to call it home!

Now, you might be thinking, "But wait, what exactly IS a planet?" That's a fantastic question, and understanding the answer will help you see just how special Earth really is. A planet is like a giant ball of rock, gas, or ice that travels around a star—in Earth's case, that star is our Sun. Our Sun is so enormous that you could fit about 1.3 million Earths inside it! Think about that for a second: 1.3 million Earths could fit inside the Sun. That's like comparing a tiny marble to a giant beach ball. But here's the truly amazing part—while the Sun is incredibly important to us because it gives us light and warmth, we're actually quite far away from it, and that distance is absolutely perfect.

Scientists call the area around a star where conditions are "just right" for life the Goldilocks Zone. Remember the story of Goldilocks and the Three Bears? She tried Papa Bear's porridge and it was too hot, Mama Bear's porridge was too cold, but Baby Bear's porridge was just right. Well, Earth is in the "just right" spot around our Sun! If we were closer to the Sun, it would be too hot and all our water would boil away. If we were farther away, it would be too cold and everything would freeze. But right here, in this perfect spot, we have the exact right temperature for liquid water—and liquid water is absolutely essential for life as we know it. No other planet in our solar system has the perfect conditions that Earth has. Mars is too cold, Venus is hotter than any oven you've ever seen, and Mercury swings between freezing and burning. Earth? Earth is absolutely, perfectly, wonderfully just right!

Let's take a virtual trip around our planet and discover all the incredible places that make Earth so special. First, let's dive into the oceans. Did you know that more than 70 percent of Earth's surface is covered by water? That's like if you had a basketball, and you covered most of it with a wet towel—the water part would be much bigger than the dry part. These oceans are so huge that we've actually explored less than 20 percent of them! That means there might be creatures and places in our oceans that humans have never even seen before. How cool is that? The oceans are home to the largest animal that has ever lived on Earth—the blue whale. These magnificent creatures can grow up to 100 feet long and weigh as much as 200 tons. That's about the same weight as 25 elephants stacked together! But the ocean isn't just about big animals. It's also where some of the tiniest creatures on Earth live. Tiny plants called phytoplankton float near the ocean surface, and even though they're smaller than the period at the end of this sentence, they produce about half of the oxygen you breathe. Every time you take a breath, you can thank the ocean!

Now let's leave the water and climb up high—way, way up into the mountains. Earth has some of the tallest mountains in our entire solar system. Mount Everest, which sits in the Himalayan Mountains in Asia, is so tall that its peak reaches 29,032 feet into the sky. That's so high that the air there has less than one-third of the oxygen that you breathe at sea level. Climbers who attempt to reach the top have to carry tanks of oxygen just to breathe! The mountain is so tall that if you could drive a car straight up at highway speeds, it would take you about six hours to reach the summit. But here's a mind-blowing fact: if you measure mountains from their base on the ocean floor instead of from sea level, Hawaii's Mauna Kea is actually taller than Mount Everest! It starts from deep underwater and rises over 33,000 feet total. Now that's what I call a tall mountain!

From the mountains, let's drift down into the forests. Forests cover about 31 percent of all land on Earth, and they're absolutely packed with life. The Amazon Rainforest in South America is so enormous that it's bigger than the entire countries of France, Germany, Spain, and Portugal combined! This massive forest is home to one out of every ten animal species on Earth. Scientists discover new species there every single year—sometimes hundreds of new species in just one year! Forests are like the lungs of our planet because the trees take in carbon dioxide (which comes from things like car exhaust and factory smoke) and breathe out oxygen. So every tree you see is like a tiny air-cleaning machine, working 24 hours a day to make the air cleaner for all of us. In fact, a single large tree can provide a day's worth of oxygen for four people. So if you have trees in your neighborhood or near your school, you can thank them for the air you breathe!

But Earth isn't just about geography and landscapes—it's about the incredible creatures that call it home too. And that includes you! Every single living thing on Earth plays an important role, kind of like how every player on a sports team has a special job. The bees help flowers make seeds by carrying pollen from flower to flower. Worms help make soil healthy by eating dead leaves and turning them into nutrients that plants can use. Even tiny bacteria in the ocean help regulate our climate by absorbing carbon dioxide. Every creature, no matter how big or small, has a purpose and belongs here. You belong here too, and just like every other creature on Earth, you have an important role to play. That's one of the most wonderful things about our planet—everyone and everything has a place, and we're all connected.

Here's another amazing thing about Earth: it's been around for a very, very long time. Scientists estimate that our planet formed about 4.5 billion years ago. That's so long ago that if you tried to write out all the zeros, it would look like this: 4,500,000,000 years! If all of Earth's history were compressed into a single year, humans would appear on December 31st at about 11:36 PM. That means that for most of Earth's history, dinosaurs roamed the planet—and they were around for about 165 million years! Humans, by comparison, have only been around for a tiny fraction of that time. But in our short time on Earth, humans have done some pretty remarkable things. We've built cities, created art, discovered scientific principles, and even traveled to the Moon. We've also, unfortunately, done some things that have hurt our planet. But that's exactly why this book exists—to help you learn how to be a Planet Protector!

Meet Your Friendly Guides

Before we go any further on our Earth adventure, let me introduce you to some very special friends who will be joining us throughout this book. They're called the Planet Protectors, and they're here to teach you everything you need to know about taking care of our amazing planet!

First, there's Terra the Turtle. Terra is a wise old sea turtle who has been swimming through Earth's oceans for over 100 years. She has seen coral reefs full of colorful fish that are now bleached white. She has swum through waters that were once crystal clear but are now filled with floating plastic. But she hasn't given up hope—not even close! Terra believes that young people like you have the power to change the future. She's patient, kind, and knows more about the ocean than almost anyone. Her shell has beautiful patterns that represent different e