The strangers in your dreams are actually people that you've seen in real life.
50
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
Mars had an oxygen-rich atmosphere around 4 billion years ago
13
There is a persistent storm in Venezuela that produces lightning 140 to 160 nights a year, 10 hours per day and up to 280 times per hour and has been going since at least the 16th century.
25
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
81