Mongo and Mongonians
Mongo is a dark planet roughly the size of Mercury, whose atmosphere is cloaked in a sun obscuring layer of thick dust or smog of some sort. Being less bright than a small asteroid, even at closest approaches, seen only occasionally, it was often mistaken for a comet or asteroid. As such the sky is very diffuse light in perpetual twilight conditions, the sun an indistinct body, even the twilight and evening sky unaccountably bright with refracted sunlight. Mongo, like the planet Mercury, is a dense metallic ball with a much thinner rock crust, with a surface gravity of about 65% of Telestia. While its exact orbit is unknown, the most common estimate is 16 months, making its orbit about 1.2 Astronomical Units. Mongo’s angle to the ecliptic is extreme, so it only passes the plane of the ecliptic for only a few days every 8 months. Between its lack of luminosity (albedo) and that it only very occasionally crossed into the view where astronomers searched, Mongo’s existence went undetec...