Third planet of eight recognized planets and hundreds of moons and dwarf planetoids in the human home-system known as Sol System. Also notable because of its relatively large moon.
For centuries, due to the perfection of organ transplant technology, all state executions are done in hospitals to provide organ transplants, and to maximize their availability, nearly all crimes carried the death penalty. This period ended when Jack Brennan, who had consumed the Tree-of-Life root and become a human version of the Protector, used his superior intelligence to engineer social change in medical technology and social attitudes that eventually reduced the use of organ banks to reasonable levels. Part of Brennan's manipulation was the development of a science known as 'psychistry' used to 'correct' all forms of 'mental aberration'—the populace is incredibly docile. To combat overpopulation (one estimate is 18 billion people), a license is required to procreate, only available after exhaustive testing has determined that a prospect is free of 'abnormalities'; failure to acquire one before procreating is a capital crime.
This policy, in addition to the existence of the transfer booth and a one-world language and economy, has led to the populace eventually becoming fairly genetically homogeneous. To prevent the development of new Weapons of mass destruction, all scientific research is regulated by the ARM and all potentially dangerous technology is suppressed; there have been very few real breakthroughs in science since the twentieth century.
A common title for people born on Earth is 'Flatlander'; they are considered naïve and a bit helpless by the rest of the galaxy, having been born and raised in the only environment in Known Space without inherent dangers.