The Planet Earth

The Earth emerged from a swirling nebulae of interstellar gas and dust along with the Sun and other bodies in our Solar system .Countless tiny minerals grains collided with each other under the force of inherent gravity and condensed into larger planets like the Earth .

The Earth is the third planet from the sun with only one Moon and to support life form .The Earth looks like a spheroid but is flatter at its poles,making it an oblate spheroid, with an equatorial diameter of 12,756 km and a polar diameter of 12,714 km .It rotate once on its own axis, tilted at an angle of 23.5 degrees every 23hour,56minutes,and orbit around the Sun in an ellipse in 365days,6hours and 8minutes

Seasons and Earth-Sun Relations

The axial tilt of the Earth of 23.5 degrees as it moves around the Sun causes seasonal changes .When in June the northern hemisphere tilts towards the Sun,it gets maximum heat while the southern hemisphere gets little heat .In is thus summer is on the northern hemisphere and winter is in the southern hemisphere .Six months later,in December, the situation is reversed as the Earth travels halfway around the Sun and its northern hemisphere is tilted away from the sun .

On 21June,the Sun is directly overhead the head the tropic of cancer(23.5degrees north) and it it is in mid summer in the northern hemisphere .Mid summer in the southern hemisphere occurs on 22 December when the sun is directly overhead the tropic of Capricorn (23.5 degrees South) .