• The one place where a flag flies all day, never goes up or comes down, and does not get saluted, is the moon.

• All the planets in the solar system rotate anticlockwise, except Venus. It is the only planet that rotates clockwise.

• Earth is the densest planet in the solar system and the only one not named after a god.

• Earth orbits the sun at an average speed of 29.79 km/s (18.51 miles/sec), or about 107 000 km/h (about 67,000 miles/hour).

• The sun is 330,330 times larger than the earth.

• Earth is slowing down — in a few million years there won’t be a leap year.

• The tail of the Great Comet of 1843 was 330 million km long. (It will return in 2356.)

• 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.

• Organist William Herschel discovered the planet Uranus in 1781 with the first reflecting telescope that he built. He named it Georgium Sidium in honour of King George III of England but in 1850 it was renamed Uranus in accordance with the tradition of naming planets for Roman gods.

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

• About 500 small meteorites fall to earth every year but most fall in the sea and in unpopulated areas.

• There is no record of a person being killed by a meteorite but animals are occasionally hit.

• During a total solar eclipse the temperature can drop by six degrees Celsius (about 20 degrees Fahrenheit).

— Compiled by Yasha