Rotation and Revolution

ROTATION AND REVOLUTION OF THE EARTH

Rotation

     The earth spins on its own axis from West to East in twenty four hours is called a Rotation. The earth's axis is an imaginary line drawn between North and South Poles. The tilted position of the earth is called Inclination. The inclination angle is 23.5 degree perpendicular to the ecliptic plane and 66.5 degree with the orbital plane to the sun. It takes 23 hours 56 minutes 4 seconds to complete one rotation. The equatorial surface of the earth is rotating with the speed of 1656 km per hour. The equatorial circumference of the earth is 40,075 km is rotated once in a day.

Effects of Rotation

• Rotation causes day and night on the earth.
• Causes different sunrise and sunset timings on different longitudes.
• Causes the centrifugal force of the earth.
• Causes atmospheric pressure and deflection of winds.
• Causes ocean currents. 
• Causes tides twice a day.

Revolution

     The earth moves around the sun on its orbit once in every 365.25 days. This is known as Revolution. It revolves East to West around the sun. Earth is inclined at the angle of 23.5 degree with the perpendicular to the plane of its orbit and 66.5 degree with orbital plane. its revolving speed is 108,000 km per hour. Aphelion is the position of longest distance between sun  and earth during revolution. July 4 is the Aphelion, on the day the distance between the sun and earth is 152 million km. Perihelion is the position of shortest distance between the sun and earth during revolution. January 3 is the Perihelion, on the day the distant between the sun and earth is 147 million km.

Effects of Revolution

• Revolution causes changing of seasons in every year.
• Causes Equinoxes twice in a year.
• Causes summer and winter solstices
• Causes Twilight and Dawn.