Darian calendar Darian calendar The Darian calendar is a proposed system of time-keeping designed to serve the needs of any possible future human settlers on the planet Mars. It was created by aerospace engineer, political scientist, and space jurist Thomas Gangale in 1985 and named by him after his son Darius. It was first published in June 1986. The basic time periods from which the calendar is constructed are the Martian solar day (sometimes called a sol) and the Martian vernal equinox year, which is . The sol is 39 minutes 35.244 seconds longer than the Terrestrial solar day and the Martian
Fictional planets of the Solar System a "tenth planet". Since 1992, a very large number of objects have been found beyond Neptune; all the objects in the following list, however, are purely fictional. Common names for trans-Neptunian planets in fiction include Planet X, after a planet once believed to lie beyond Neptune, and Persephone (or Proserpina), after the wife of Pluto. Rogue planets in fiction usually originate outside the Solar System, but their erratic paths lead them to within detectable range of Earth. In reality, no rogue planet has ever been detected transiting the Solar System. Fictional planets of the Solar System The fictional portrayal of