Since ancient times, astronomers have declared that our Sun must have ten planets, rather than the official nine. Providence designs with care and symmetry, after all, so nine planets simply won’t do. Clearly there must be a hidden planet.
The wise old astronomers were right. Kidlandia, the tenth planet, lay undiscovered because it is invisible to adults. Only when children were given telescopes was Kidlandia revealed to human eyes, but they of course are sworn to secrecy.
Kidlandia is a watery world, with 90% of its surface covered with seas and lakes. The planet has a diameter of 22,248 miles, or roughly three times that of Earth, and orbits in an elliptical pattern one third of the way from Earth to Mars. Most of the planet has yet to be explored.
Intelligent life arrived on Kidlandia four thousand years ago on the ship Adytum, a refugee vessel filled with Kreechurs from the planet Cynicide, following a takeover by an evil theocracy
From the safety of Kidlandia, the Kreechurs observed adult human behavior on Earth with concern, and decided that only children would be allowed to rule the lush lands of their planet. They also employed a spherical harmonic invisibility technology to protect the planet from the covetous eyes of adult humans, in the remote chance they might develop rocket ships (which they did).
One adult human landed on Kidlandia by accident. His name is Brian Backus, and after proving his innocent intent to the Kreechurs, he was appointed titular king. His primary purpose is to serve the happiness of Kidlandia's young rulers. King Brian was also appointed Kidlandia’s official cartographer to make sure he is too busy for mischief, because Kidlandian’s believe rulers are there to serve, not to take.
Kidlanida exists so that young ruler’s can become kinder, smarter, better people who live to give. If you know a worthy child, you may apply for a realm on his or her behalf.
Kidlandia has yet to experience war or extinction.