Archive · 22 May 2025
Polaris Isn't Always North Star: Earth's Wobble Explained
Imagine Earth is a spinning top, and it wobbles a little as it spins.
This wobble, called precession, takes about 26,000 years to complete.
Because of this wobble, the star that points north in the sky changes over time.
Right now, Polaris is our North Star, but it wasn't always and won't be forever.
Thousands of years ago, Thuban was the North Star.
In the future, stars like Errai and Vega will take their turn.
This is because the Earth's wobble causes the direction to the north to change very slowly.
Earth's axial wobble, called precession, causes a shift in the North Star over time.
The cycle of precession lasts approximately 26,000 years, influencing which star is closest to the celestial pole.
Polaris has been the North Star for thousands of years.
Stars like Thuban, Kochab, and Vega have served as the North Star at different points in history.
The position of the North Star will continue to change, with Errai being next.
- Who
- Earth and various stars (Polaris, Thuban, Errai, etc.)
- What
- The shift in the North Star due to Earth's wobble.
- When
- Over a 26,000-year cycle
- Where
- The Northern Hemisphere
- Why
- Due to Earth's axial precession caused by gravitational forces from the sun and moon
- Precession Cycle
- Approximately 26,000 years
- Current North Star
- Polaris
- Thuban as North Star
- 4,700 years ago
- Errai to become North Star
- In about 2,200 years
- Vega returning
- In roughly 12,000 years