About four and a half billion years ago, Earth was born. Gradually, after its surface became solid, the atmosphere appeared, then water, and life. Rocks and fossils together reveal how this fascinating evolution of Earth became the planet we know today.
The Origin of Earth Earth Science, General Science
The Formation of Earth Earth Science, General Science
The Structure of the Universe General Science
What Killed the Woolly Mammoth General Science
Venus General Science
© National Geographic Society 2009
• Terms of Service
• Privacy Policy
Site by Logicbox
& Idea Junction
