Revolution vs Rotation

Rotation &

Rotation

• Rotation: the spinning of an object on its axis
• Axis: an imaginary pole that something, such

as the Earth spins on

• Earth’s axis runs through
its center at an angle and the
ends of the axis are the north
and south poles
• Earth rotates at a 23 ½⁰ angle

Period of Rotation

• One day is one period of rotation and is

defined as a planet making one rotation on its
axis

• One day on Earth=24 hours
• All planets rotate and every planet has a

different length of rotation

Day and Night

• At any given time, only one half of any planet

is experiencing daylight and one half is
experiencing darkness because only half of a
planet faces the sun at a time. The other half
is in shadow.

Day and Night

• Rotation causes day and night on all planets
• Earth rotates
counter clockwise
causing the sun
to rise in the east
and set in the
west

Revolution

What is the shape of Earth’s Orbital Path?

Ellipse

Period of Revolution

• One year is one period of revolution and is

defined as the time it takes a planet to revolve
around the sun once

• One year on earth=365 ¼ days
• Every four years we have a leap year
• The farther away the planet is from the sun,

the longer its year will be

Multiple Choice

One year on Earth is 364 1/4 days. This is one _______.

• Season

• Day

• Revolution

• Rotation

Rotation vs. Revolution

• “The world doesn’t revolve around you!”
• Remember that revolution is one celestial

body going around another celestial body

• Rotation is a planet spinning on its own axis

Rotation
Revolution

Natural Satellites

• Natural satellites also rotate and revolve

around their planets as their planets rotate
and revolve around the sun

Open Ended

Describe the difference in rotation and revolution: