Martok is a gas giant located in the habitable zone of the Bacto sun. Its atmosphere consists of hydrogen and methane, with a few water vapor clouds, mostly around the poles. This gives the giant's equatorial area a flat, plain blue appearance, with storms of thick white clouds around the poles of the planet.
Because Bactara is tidally locked to Martok, the giant appears to hang in the same place in the sky; its apparent diameter from Bactara is 13 degrees, or about 25 times the angular size of the moon seen from Earth. Depending on its phase, it may provide nighttime illumination that is a significant fraction of the daytime illumination on Bactara—over 600 times as bright as a full moon on Earth, or just under 1/10 of the illumination from Bacto.
Martok is worshipped by many Bactarans, with the most famously devout of them belonging to the House of Martoki, whose main territory lies directly on the closest point on the Bactaran surface to Martok. Martoki temples are designed and constructed with a skylight, aimed towards Martok, in such a way that Martok's reflected light illuminates the temple's pulpit; Martok's light is considered holy. A frequent holy incidence is the "full Martok", when the giant is brightest in the sky; this happens at midnight on each of Bactara's 300-hour "days".