Tilt of the earth's axis. Why does it change?

In summary, the Earth's axial tilt fluctuates between 22 and 24 degrees due to the gravity gradient torque caused by the Earth's equatorial bulge. This allows other bodies such as the Moon and Sun to exert a gravitational force and change the tilt of the Earth. The Earth's shape, specifically its equatorial bulge, is the main factor in causing the tilt to change.
  • #1
McLaren Rulez
292
3
I recently read that the Earth's axial tilt fluctuates between 22 degrees and 24 degrees. Can someone explain what causes the tilt to change? If I assume the Earth is perfectly spherical, gravitational forces cannot change the tilt.

So, is that the reason i.e. that the Earth is not perfectly round?

Or is there a different explanation for the tilt angle change?

Thank you
 
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  • #4
The idea of ice build up near the poles seems plausible. But I have found several sources that claim that other planets have an effect: For instance, the moon is said to stabilize the tilt change. Can someone explain how another body can exert a gravitational force that changes the tilt of the earth?

Thank you.
 
  • #5
The Earth is not a perfect sphere. The largest deviation from spherical is the equatorial bulge caused by the Earth's daily rotation. Because gravity is a 1/r2 force, this equatorial bulge gives the Moon and Sun a handle that their gravitational fields can grab on to. Technically it's called gravity gradient torque. It is this gravity gradient torque that causes the Earth's rotation axis to precess and nutate.
 
  • #6
Thank you!
 

1. What is the tilt of the earth's axis?

The tilt of the earth's axis refers to the angle at which the earth's axis is tilted in relation to its orbit around the sun. This tilt is approximately 23.5 degrees.

2. Why does the earth's axis tilt?

The exact reason for the earth's axis tilt is still a topic of scientific research and debate. However, it is believed that the tilt is a result of the way the solar system was formed and the distribution of mass within the system.

3. What causes the tilt of the earth's axis to change?

The tilt of the earth's axis changes due to a phenomenon known as precession. This is when the earth's axis wobbles slightly, causing the tilt to vary by a few degrees over a period of approximately 26,000 years.

4. How does the tilt of the earth's axis affect the seasons?

The tilt of the earth's axis is one of the main factors that determines the changing of seasons. As the earth orbits around the sun, the tilt causes different parts of the earth to receive varying amounts of sunlight, resulting in the different seasons we experience.

5. Is the tilt of the earth's axis constant?

No, the tilt of the earth's axis is not constant. As mentioned before, it undergoes a slight wobble called precession, causing the tilt to change over a long period of time. Additionally, there are also other factors that can cause small variations in the tilt, such as gravitational pull from other planets in the solar system.

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