Motions of the Earth

There 2 major motions of the Earth Rotation and Revolution.

Rotation: The daily motion of the Earth is called Rotation. The Earth takes 24 hours to rotate once on it's axis. Rotation causes day and night.

Revolution: The yearly motion of the Earth is called Rotation. The Earth takes 365^1/4 day to revolve once around the sun on a fixed path called Orbit. Revolution causes change in seasons.

Axis: Axis is the imaginary pole on which the Earth rotates. It has a inclination of 66.5 / 23.5 degrees.

Orbit: A fixed path on which the Earth revolves is called "Orbit". The plane formed by the orbit is called "Orbital Plane".

The circle/line which is the boundary of day and night is called circle of illumination. It bisects the Earth in 2 equal parts. It measures 23.5 degrees.

#Solstice: The sun standing still.21^st June: Summer solstice

Ø Tilted towards the sun (northern hemisphere).

Ø The sun rays will fall tilted on tropic of Cancer.

Ø Days are long and Nights are short.

22^nd December: Winter solstice

Ø Tilted towards the sun (southern hemisphere).

Ø The sun rays will fall tilted on tropic of Capricorn.

Ø Days are short and Nights are long.

EQUINOXES:

When the whole Earth experience equal days and nights.

21^st March: Spring/vernal equinox

Ø Northern hemisphere has spring.

Ø Southern hemisphere has autumn.

Ø Sun shines vertically on the equator.

Ø The length of the days and nights all-over the Earth.

23^rd September: Autumnal equinox

Ø Sun shines vertically on the equator.

Ø The length of the days and nights all-over the Earth

Ø Northern hemisphere has autumn.

Ø Southern hemisphere has spring.