10 Need-to-Know Things About Earth

10 Need-to-Know Things About Earth:

1. If the sun were as tall as a typical front door, Earth would be the size of a nickel.
2. Earth is the third planet from the sun at a distance of about 150 million km (93 million miles) or one AU.

   Spacecraft study Earth from above.

3. One day on Earth takes 24 hours (this is the time it takes the Earth to rotate or spin once). Earth makes a complete orbit around the sun (a year in Earth time) in about 365 days.
4. Earth is a rocky planet, also known as a terrestrial planet, with a solid and dynamic surface of mountains, valleys, canyons, plains and so much more. What makes Earth different from the other terrestrial planets is that it is also an ocean planet: 70 percent of the Earth's surface is covered in oceans.
5. The Earth's atmosphere is made up of 78 percent nitrogen (N₂), 21 percent oxygen (O₂) and 1 percent other ingredients -- the perfect balance for us to breathe and live. Many planets have atmospheres, but only Earth's is breathable.
6. Earth has one moon. Another name for a moon is satellite.
7. Earth has no rings.
8. Many orbiting spacecraft study the Earth from above as a whole system and together aid in understanding our home planet.
9. Earth is the perfect place for life.
10. Earth's atmosphere protects us from incoming meteoroids, most of which break up in our atmosphere before they can strike the surface as meteorites