Distance from sun (million km): 150
Revolution: 365 days, 5 h, 48 min, 47 sec
Diameter (equator): 12.756 km
Period of rotation: 23 h, 56 min
Tilt: 23.5 degree

Earth is the only inner planet in our solar system that has liquid water on its surface. Seventy percent of the surface is covered by oceans.

The tilt determines the change in seasons (without the tilt, we would have the same season all year long). Our planet has a core of liquid iron-nickel. Earth's surface has been affected by volcanism, tectonic activity, and meteorite impacts.

The atmosphere contains 21% oxygen (necessary to breathe), 78% nitrogen, and 0.9% argon. The other 0.1% consists of water vapor, carbon dioxide, neon, methane, krypton, helium, xenon, hydrogen, nitrous oxide, carbon monoxide, nitrogen dioxide, sulfur dioxide, and ozone (if present in larger amounts, most of these latter elements would be poisonous to humans).