Definition: Earth: Our home planet, third from the sun. Earth is the only planet in our solar system not named for an ancient god. In the image on the right, this is the view Apollo 8 astronauts had of Earth while orbiting the moon.
"Earth"
By Nick Greene, About.com
Free Email Courses
Explore Space / Astronomy
Must Reads
More from About.com
Work Hard, Travel Easy
The best tips for business travelers.Dog Care
Get tips on training and caring for dogs of all ages.48 Hours in Vegas
Plan a hot weekend in Sin City.Hotel Advice
The must-stay hotels worldwide.
©2008 About.com, a part of The New York Times Company.
All rights reserved.