Summer on Uranus lasts for 21 years – but so does winter.

Planets, meaning wanderers, are named after Roman deities: Mercury, messenger of the gods; Venus, the god of love and beauty; Mars, the god of war; Jupiter, king of the gods; and Saturn, father of Jupiter and god of agriculture; Neptune, god of the sea.

One year on earth is 365.26 days long. One day is 23 hours, 56 minutes, and 4 seconds long. The extra day in a leap year was introduced to compensate for the discrepancy in the Georgian calendar.

There are more than 326 million trillion gallons of water on Earth.

More than 70% of earth’s dryland is affected by desertification.