Earth as a cosmic matter

The Solar System

Desk or round shape?Elliptical orbits?

The Sun-Centre of the Universe?

Heliocentric system Gravitation

Mikulas Kopernik Johannes Kepler

Issac Newton

Different Climatic Zones

About 4.75 billion years ago…

…out of solar nebula

Weight: 80 times smallerDistance:60 times Earth’s radius

Important sunlight

Ocean tides

Earth’s rotation around the Sun

The Sun

The orbital speed: 30km/sec

The length: 940mil.kmThe time: 365days 5hours 48min 45.7sec = 1sidereal year

Earth’s rotation around its axis

Time of rotation: 23 hours 56 minutes 4.091 seconds= 1 sidereal/astral day

The cause of the seasons is that the rotation axis is not perpendicularto its orbital plane, but makes anangle about 23.44 degrees.

Diagram of the Earth's seasons as seen from the north. Far right: December solstice

Diagram of the Earth's seasons as seen from the south. Far left: June solstice

Time zones