Jasoom (known to us as Earth) is the third planet, located between Barsoom (Mars) and Cosoom (Venus). It is home of John Carter and Ulysses Paxton, who were relative unknowns on Earth but became distinguished heroes on Mars. The distance between Jasoom and Barsoom is 48 million miles, and thus only two Earthmen are known to have travelled to Barsoom, and no Martians have ever made it out to Jasoom, though Martian science had, by 1917, developed the means to view and hear things on Earth, and the study of Chinese, English, French, Spanish, Russian, and various other languages became a hobby of wealthy intellectuals in kingdoms like Toonol, particularly when news began to spread of the exploits of Carter and Paxton. The Earth has one natural satellite, typically it is referred to as "the moon" but its actual name is Luna. The planet is excessively complex, with many secrets, races, and nations. Africa in particular has many secrets unknown to the great world.