Your body is creating and killing about 2.4 million red blood cells per second.
17
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
Only about 2% of the world population has green eyes.
36
The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21
It's possible to die from a broken heart; it's called Stress Cardiomyopathy.
165
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