Earth Rotation and Revolution: Definition, Differences and Facts

Earth Rotation refers to when Earth spins on its axis, completing one rotation every 24 hours, causing day and night. Earth Revolution occurs when Earth orbits around the Sun, taking about 365 days, resulting in the changing seasons.

In this article, we have discussed the Rotation and Revolution of the Earth, Differences, Facts, and many more about the Revolution and Rotations of Earth.

Earth Rotation and Revolution

Let’s dive right in.

What is Rotation?

• Definition: The spinning of the Earth on its axis.
• Axis: Imaginary line passing through the North and South Poles.
• Direction: From west to east.
• Duration: Takes approximately 24 hours for one complete rotation.
• Effect: Causes day and night.

Rotation can be defined as a circular movement of any object around an axis or center of rotation. An axis is an imaginary line around which three-dimensional objects like Earth, sun, or moon rotate. When an axis goes through a body’s center of mass, the body is said to be rotating or spinning on its own.

What is Revolution?

• Definition: The Earth’s orbit around the Sun.
• Orbit: Elliptical path around the Sun.
• Duration: Takes approximately 365.25 days for one complete revolution.
• Effect: Causes changes in seasons.
• Axis Tilt: Earth’s axis is tilted at about 23.5 degrees.
• Ecliptic Plane: Plane of Earth’s orbit around the Sun.

Revolution is often associated with rotation. However, in the field of astronomy and related subjects, revolution signifies an orbital revolution. The term is used to describe the movement of one body around another, while rotation indicates moving around its own axis. For example, the Earth revolves around the Sun and rotates on itself.

Rotation of the Earth

Earth rotates in the direction of west to east, and as a result, the Sun and the Moon appear to move from east to west across the sky. The angle at which the earth rotates on its axis is 23 1/2º and it lies perpendicular to the plane of Earth’s orbit. This indicates that the Earth is tilted on its axis due to which the northern and the southern hemispheres lean in a direction away from the Sun. The Earth’s rotation divides it into two halves of light and darkness which leads to day and night.

• Speed: Rotates at a speed of about 1670 kilometers per hour at the equator.
• Coriolis Effect: Causes the deflection of moving objects due to Earth’s rotation.
• Day and Night: The rotation cycle results in alternating periods of daylight and darkness.
• Equator vs. Poles: Different rotational speeds at the equator and poles.

The direction of the Earth’s rotation is determined by the direction of viewing. The earth spins counterclockwise when it is viewed from the North Pole while it spins clockwise when viewed from the South Pole.

Revolution of the Earth

When one body moves around another body in a fixed trajectory, it is called revolution. For example, the earth revolves around the sun in the anticlockwise direction (west to east). One revolution of earth around the sun takes 365.24 days to complete which is referred to as one year. The revolution speed is around 30 km/s.

• Speed: Revolves at an average speed of about 107,226 kilometers per hour.
• Orbital Shape: Earth’s orbit is elliptical, but nearly circular.
• Perihelion: Closest point to the Sun (around January 3).
• Aphelion: Farthest point from the Sun (around July 4).
• Impact on Seasons: Varies distance from the Sun, influencing the intensity of seasons.

Difference between Rotation and Revolution

The following are the difference between Roatation and Revolution:

Rotation	Revolution
Rotation can be defined as a circular movement of any object around an axis or centre of rotation.	When one body moves around another body in a fixed trajectory, it is called revolution.
Earth takes 24 hours to complete one rotation.	Earth takes 365 days to complete one revolution around the sun.

Revolution of the Earth Depends on

The revolution of the earth depends on the following:

1. Orbit Shape- Shape of the earth orbitis ellipse, which means that at certain times of the year, earth is closer to the sun and at times, it is farther away as well.
2. Speed of Revolution- Earth travels at an average speed of 29.78 kilometers per second in its orbit around the sun.
3. Tilted Axis- The axis of the earth is tilted at an angle of 23.5 degrees relative to its orbit around the sun.
4. Seasons- As the earth orbits around the sun, the tilt in the axis causes different parts of the planet to either receive more less sunlight.
5. Equinoxes and Solstices- There are two equinoxes and two solstices during earth’s orbit.

Importance of Earth Rotation

The rotation of the earth is of paramount importance.

• The Earth’s rotation is responsible for creating the diurnal cycle of lightness and darkness, changes in humidity and temperature.

• The tides in the oceans and seas are also caused by the rotation of the Earth.

Importance of Revolution

• Revolution is responsible for causing seasons.

• Perihelion and aphelion is created by revolution. When the Earth is closest to the Sun, perihelion happens while the opposite aphelion occurs when the Earth is farthest from the Sun.

• Revolution is also responsible for the difference in length of day and night time. Near the equator, the duration of daytime and nighttime almost remains the same. This phenomenon is called the equinox. There is variance in the duration of day and night when one moves towards the Northern and Southern hemispheres. This is called solstices,

Rotation and Revolution of different planets

The following are the list of Revolution and Rotation and of different planets:

Planet Name	Mean distance of planet from Sun (million km)	Revolution period	Rotation period
Mercury	57.9	88 days	59 days
Venus	108.2	224.7 days	243 days
Earth	149.6	365.2 days	23 hours, 56 minutes, 4 seconds
Mars	227.9	687 days	24 hours, 37 minutes
Jupiter	778.3	11.86 years	9 hours, 55 minutes, 30 seconds
Saturn	1427	29.46 years	10 hours, 40 minutes, 24 seconds
Uranus	2870	84 years	16.8 hours
Neptune	4497	165 years	16 hour, 11 minutes

FAQs on Rotation and Revolution

What is meant by Rotation?

Rotation can be defined as a circular movement of any object around an axis or centre of rotation.

What is meant by Revolution?

When one body moves around another body in a fixed trajectory, it is called revolution.

Do earthquakes affect the Earth’s rotation?

NASA, with the help of data collected from Indonesian earthquake, discovered that the rotation of the earth was affected by the earthquake. The earthquake moved the North Pole by few centimetres which affected the duration of day and night. The earthquake caused an aftermath tsunami leading to change in the Earth’s rotation.

How many days does earth take to complete one rotation and one revolution?

The Earth takes 24 hours to complete one rotation and 365.24 days to complete one revolution around the sun

What is the angle made by the axis of the earth with its orbital plane?

The earth makes an angle of 66 degrees with its orbital plane.

What is an equinox?

An equinox is defined as the date or time at which the sun crosses the equator in such a way that the length of the day and night are equal. This phenomenon happens twice a year.