Mars had an oxygen-rich atmosphere around 4 billion years ago
13
Your thumb is about the same size as your nose.
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The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
The oldest glowing lightbulb was first switched on in 1901 and lives in fire stations in Livermore, CA. It is known as the Centennial Light.
118
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
A cow produces around 200,000 glasses of milk in her lifetime.
373