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
Solar System all have impact craters and tectonic surface features, such as rift valleys and volcanoes. The term "inner planet" should not be confused with "inferior planet", which designates those planets that are closer to the Sun than Earth is (i.e. Mercury and Venus). Asteroids except for the largest, Ceres, are classified as small Solar System bodies and are composed mainly of refractory rocky and metallic minerals, with some ice. They range from a few metres to hundreds of kilometres in size. Asteroids smaller than one meter are usually called meteoroids and micrometeoroids (grain-sized), depending on different, somewhat arbitrary definitions. The asteroid