Earth, the largest 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. It is cool on the surface but very hot deep inside the planet. The center, or core, is as hot as 9000 degrees F.
The Earth's surface is unique from the other planets because it is the only one with liquid water. Water helps to make surface features such as rivers, lakes and oceans. The moving plates of the Earth’s surface form other surface features such as mountains, earthquakes and volcanoes.





We now offer the Cool It! card game in our Science Store. Cool It! is the new card game from UCS that teaches kids about the choices we have when it comes to climate change.
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