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
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
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
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82