Buga
The forth planet in the system is planet Buga. Almost similar in appearance to Mars, Buga gives the appearance of the Russian tundra (over the Martian look of the Australian outback). Any liquids would be frozen, the atmosphere is thin, and there is little to no magnetic field shielding the planet. Some subterranean life has been found on the planet, which would be comparable to worms on Earth.
Buga has one moon, Russalki. Similar to the Earth-Luna system, the Buga-Russalki system is very similar. Russalki is nearly half the size of Buga, and both bodies orbit a common barycenter. However, the barycenter is visible, it is roughly near the surface of Buga. Because of their extreme proximity and size, only one side of each body is facing the other (similar to Pluto and Charon).