Our planet is unique within the solar system. Four-and-a-half billion years ago it had a twin named Theia which was absorbed into the Earth, increasing its gravity and allowing it to form an atmosphere. Iain travels to Meteor Crater in Arizona to explore the atmosphere's role in protecting us from bombardment by meteorites. Life on earth only prospers because it is provided with right amount of heat from the sun. |
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Title: | Rare Earth | |
Air Date: | December 18, 2007 | |
Runtime: | 60 min | |
Genres: | Nature | |
yellow_rose1 : Contains spoilers. Click to show. I had not heard of this case before now. It was refreshing to watch something different. T...