The Earth from space.
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Image courtesy of NASA/JPL
Surface and Interior of Earth
Earth, the largest and densest rocky planet, was formed about 4.5 billion years ago. The Earth's interior is divided into four layers which is typical of rocky planets. Each layer has different characteristics and is made of different elements and minerals. There is a gradient in temperature between the cool surface and the hot interior with the center, or core, as hot as 9000 degrees F.
There are many different types of features on Earth’s surface due to the complexity of our planet. The surface is unique from the other planets because it is the only one which has liquid water in such large quantities. Water forms some features of Earth's surface such as rivers, oceans, beaches and lakes. Other surface features, such as mountains, earthquakes and volcanoes, are formed when large pieces of the Earth’s outer layer move slowly by plate tectonics.
Last modified June 3, 2008 by Lisa Gardiner.
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