Tartarus is the first rogue planet to have been discovered via the gate network, accessed through discord gate on Eris. The planet's nearest stellar neighbor is a binary system 5.3 light years away, and the only significant orbiting body is a large captured asteroid. Its gate lies in the middle of large plain of black ice, lit only by distant stars.
Scientists have determined that Tartarus is most likely similar to Europa, having an ocean of highly pressurized water under its thick surface of ice. The existence of liquid water raised the possibility of life in Tartarus' past, and an operation to bore through the ice was undertaken. Scientists were thrilled to discover that not only had Tartarus hosted life in the past, but there were complex microbial ecosystems living off of the energy of deposits of radioactive material on the ocean bottom. Stromatolites and diatomaceous earth indicate that life was once widespread, and the isolated clusters of radiotrophs are the last gasp of a family of life at least 2 billion years old.
Tartarus is livelier than one might expect from a frozen ball of rock and ice between stars. In addition to the biological research stations created to study the life of Tartarus, the planet contains several research and development workshops and laboratories designing technologies for extreme cold. The lack of nearby stars minimizes interfering stellar radiation and also makes the rogue planet an excellent location for astronomical observation; a large array of radio-telescopes is under construction.
Plot Hook: The deposits of radioactive material on which the life of Tartarus depends are anamolous. They cannot be accounted for by any models of planet formation, they are too numerous, and they are of the wrong isotopes. Some believe that this indicates intelligent activity, and that the deposits are the left over from ancient alien technologies. Firewall gives these theories some credence, and needs the PCs to investigate a possible find before word spreads to Tartarus' primary sponsor, the Go-Nin Group.