The Earth (the part that isn't water) is made up of three parts:
The Crust - a thin outer layer of rocks that is less than 100 km deep,
The Mantle - made up of rocks that are more dense (more stuff in them) than the crust,
The Core - a dense ball of metal (nickel and iron).
The outer part of the core is liquid metal. It's the motion of this metal spinning around that gives the Earth is magnetic field (makes the Earth a big magnet). The inner part of the core is solid metal - like a big ball bearing!

Uh... Let's see... Take a deep breath... Still alive? Yep, I guess you can live on the Earth! In fact, it's the ONLY place in our solar system where you can live. Without having to wear a big space suit, anyway. What makes the Earth so great? Well, it's got lots of water and oxygen... and it's a lot of places that aren't too hot or too cold for people and animals.

Just jump on a scale and find out!

To escape the earth's gravity and get out into space, a rocket has to travel at a speed of 25,100 mph or 11.18 km/sec. That's about 386 times faster than your parents are allowed to drive on a U.S. highway!  Just think of that the next time you see a Space Shuttle launching!

Just one and you can read about it here.

Sometimes Earth's magnetic field reverses itself and sometimes it shuts down completely! This means that sometimes Earth is usually a big magnet... But sometimes it isn't.

Even though the Earth is a pretty nice place to live, there's still a lot of really wild stuff that happens here! Earthquakes, volcanoes, hurricanes, tidal waves and more! You can read books about Geology (rocks, volcanoes, earthquakes and more), Oceanography (all about the oceans) and Meteorology (all about weather) to learn more about these things. We have learned a ton of stuff about our Earth... But there's still stuff we don't know! Did you know that we aren't really sure what lives in the deepest parts of our oceans?

This is why learning about science is so much fun! Maybe you'll be the one to find the answers to some of these things!

Sun | Mercury | Venus | Earth | Our Moon | Mars | Jupiter | Saturn | Uranus | Neptune | Pluto

Sources:
In Quest of the Universe, 2nd ed. by Karl F. Kuhn
Voyages Through the Universe, 2nd ed. by Fraknoi, Morrison and Wolff
Universe by Kaufmann
The Complete Idiot's Guide to Astronomy by Christopher De Pree and Alan Axelrod
The Astronomy Cafe by Sten Odenwald