EARTH

• Earth is the third planet from the sun and the fifth largest.
  
  
• Earth is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and Germanic.
  
  
• It was not until the time of Copernicus that it was understood that the Earth is just another planet.
  
  
• Earth, of course, can be studied without the aid of spacecraft.Nevertheless it was not until the twentieth century that we had maps of the entire planet.