|Year length (PST)||3/4 year|
|Day length (PST)||18 hours|
Source: The Thirteenth Gate, pg(s). 52
Silselrik lies in an elliptical orbit around a binary star system. Its core is made of extremely heavy liquid metals which bear pockets of light gases. Biannually, as Silselrik approaches the periastron, parts of the mantle become heated by the stars and mix with the denser metals at the core, only to cool off again as the planet moves towards the apastron. This results in an unstable core beneath an outer crust, which combines with the varying gravity of the twin suns to create unpredictable gravity patterns on the planet. When areas of differing gravity come into contact, they form wild gravity storms, where the gravity could be anything from crushingly severe to non-existent.
Due to the gravitic fluctuations, Silselrik's atmosphere is denser than on most worlds, and the planet is geologically unusually active: mountain ranges rise and are subsumed within mere years. Bodies of water are nearly constantly in flux, functioning more like rivers than seas and oceans. Piloting a starship to land on Silselrik is difficult for non-native pilots, who are instead supposed to dock at the space station known as the Orbital Dock, where a team of specifically trained pilots could be hired for reasonable prices to land the ship on the largest city Midios.
Silselrik's anomalous gravity provides an abundance of high-quality diamonds, pushed to the surface beneath the largest gravity storms in the most tumultous regions of the planet.
Silselrik is home to various species of sentient oozes. The most notable are the half-mile-long megalodorids, which feed upon the kinetic energy generated by gravity storms. They live in symbiosis with the intelligent selamids, who build cities called megadoplexes on the backs of megalodorids; in turn, the megalodorids feed upon the kinetic energy of the selamids and avoid the severe gravity storms that could harm them.