Convert Earth polar radius to X-unit Online | Free Length Converter

Earth Polar Radius

The Earth's polar radius is the distance from the center of the Earth to the North or South Pole. It measures the Earth’s radius along its rotational axis.

• 
  

  Its value is approximately 6,356.8 kilometers (about 3,949.9 miles).

  
  
• 
  

  The Earth is an oblate spheroid, so the polar radius is slightly shorter than the equatorial radius due to the planet's flattening at the poles.

  
  
• 
  

  This measurement is crucial for geodesy, understanding Earth’s shape, and satellite navigation.

  
  

Key facts:

• 
  

  Polar radius ≈ 6,356.8 km

  
  
• 
  

  Smaller than equatorial radius by about 21.3 km

  
  
• 
  

  Important for precise Earth modeling and mapping

  
  

The difference between the polar and equatorial radius reflects the Earth’s rotation and its effect on the planet’s shape.

X-unit

The X-unit (symbol: xu) is a very small unit of length used primarily to measure wavelengths of X-rays and gamma rays. It was introduced in the early 20th century for precision measurements in X-ray crystallography.

• 
  

  1 X-unit ≈ 0.1 picometers (pm) or 10⁻¹³ meters

  
  
• 
  

  It allows scientists to express extremely small wavelengths typical of X-rays, which are on the order of atomic spacing

  
  
• 
  

  The exact definition has varied historically, but the unit remains useful for comparing wavelengths in X-ray spectroscopy and crystallography

  
  

Though largely replaced by the picometer or ångström in modern usage, the X-unit played a crucial role in early developments of atomic-scale measurement.