Earth

           Facts about Earth

Earth was formed somewhere around 4.54 billion years ago and is currently the only known planet to support lifes. ancient astronomers believed that the Earth was static and had other celestial bodies travelling in circular orbits around it.

They believed this because of the apparent movement on the Sun and planets in relation to their viewpoint. In 1543, Copernicus published his Sun-centered model of the Solar System which put the Sun at the centre of our solar system.

Earth is the only planet not named for a mythological god or goddess. The other seven planets in the solar system were named after Roman gods or goddesses.

For the five visible to the naked eye, Mercury , Venus , Mars , Jupiter and Saturn they all were named during ancient times. This Roman method was also used after the discovery of Uranus and Neptune. The word Earth comes from the Old English word Ertha meaning ground or land.

The gravity between the Earth and the Moon causes the tides on Earth. This effect on the Moon means it is tidally locked to Earth its rotation period is the same as its orbit time so it always presents the same face to Earth.