Compared to all of the other places in space we know of: our planet is indeed an oasis on space. It is the only world we know where we can exist without elaborate life support. We evolved on this small blue world and it will remain our home until we are able to reach for other worlds.
Earth is not a particularly large planet, with a diameter of 12,756 km. It is also interesting that a typical view of the planet would be a water world. Indeed, 75 percent of the Earth is covered by water!
Orbiting 1.49 x 108km from the Sun, the Earth moves around the Sun at 29.8 km/sec. One trip around the Sun is one Earth year and it is our planet's 23.5 degree axial tilt which gives us our seasons.
Earth is the largest of the terrestrial planets, and its geologic history is fairly well understood. Because the planet is partially molten, the surface is active with plate tectonics. The surface of the Earth is ever changing, both by natural processes and processes by man.
Copyright © 1997 Kathy A. Miles and Charles F. Peters II