Mars had an oxygen-rich atmosphere around 4 billion years ago
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Lightning strikes about 6,000 times per minute on this planet!
158
Pluto is smaller than Russia.
9
The temperature of the earth's interior increases by 1 degree every 60 feet down.
115
The earth rotates more slowly on its axis in March than in September.
145
Earth is the only planet in our solar system that's not named after a god or goddess.
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