Mars had an oxygen-rich atmosphere around 4 billion years ago
13
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
A lump of pure gold the size of a matchbox can be flattened into a sheet the size of a tennis court.
140
No one knows Albert Einstein's last words. Just before he passed, he spoke several words in German, but his nurse only knew English.
154
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
Your body is creating and killing about 2.4 million red blood cells per second.
17