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One interesting fact about Earth is its status as the fifth planet in terms of size but the densest of all. It also ranks as the largest of the terrestrial planets in the solar system and the only one on which water exis... More »

www.reference.com Science Earth Science

The one and only known home for life, Earth is one of the most interesting planets of the solar system. Life on Earth is extremely diverse; however, relative to Earth's size, all of life is contained within a very thin l... More »

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The inner core is the Earth’s deepest layer, and it is a solid iron ball that is approximately 1,500 miles in diameter. Although it is extremely hot, the iron cannot melt due to the high pressure. The inner core also con... More »

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One interesting Earth fact that kids should know is that Earth is the only planet with an atmosphere that contains 21 percent oxygen. It is also the only planet known to contain life. The Earth is the third planet from t... More »

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While no one knows for certain how the Earth formed, scientists theorize that it formed over 4 million years ago after the sun went through its initial formation, gravity began to draw heavy particles together into a pla... More »

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Astronomers theorize that over 4.5 billion years ago, Theia, an object about the size of Mars, collided with Earth to create a tilted axis. This is called "the giant impact theory." Prior to this event, the axis was stra... More »

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Earth is the only planet that has liquid water on its surface, it is 93 million miles from the sun, and the Atlantic Ocean is the saltiest of the oceans. Earth is a unique planet in the solar system. More »

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