Trans-uranium decay adds a small amount of minerals to the planet's core each turn. Meteorites that strike the planet also add some minerals. See TransuraniumDecayRate, MeteorShowerOdds.
Sometimes, a large meteor hits a planet. This will add large amounts of minerals, but also do damage to the planetary structures and make the population unhappy. The resulting explosion is so big that everyone in the universe will detect it. See LargeMeteorsImpacting, RandomMeteorRate.
On temperate planets, populations grow. High tax rates reduce the growth rate. See RaceGrowthRate, CrystalsPreferDeserts.
On planets with extreme climate, large populations will eat supplies to survive, or die. See ClimateDeathRate, AllowEatingSupplies, ClimateLimitsPopulation.
Sometimes, new natives are discovered on a planet. See NewNativesPerTurn.
When there are too few colonists on a planet to support all the planetary structures, the structures will decay. See StructureDecayPerTurn, StructureDecayOnUnowned.
