This article is about Planet 4546B in Below Zero. To see this subject's article on the Subnautica Wiki, click here.

Planet 4546B is the planet on which the Aurora and the Degasi crash-landed, and is where the story of Subnautica takes place.

The Planet was set up as a research outpost by The Almanac meant to study a bacterium called the Kharaa Bacterium. The Kharaa Bacterium is a highly infectious alien bacterium discovered by the Precursors during the exploration of another world, and set up research outposts on planets to find a cure. 4546B is one of these outposts.


Planet 4546B is located in the outer reaches of the Ariadne Arm, orbiting around the star 4546. The “B” means that 4546B was the first planet discovered around the star 4546.

There are three known major ecosystems on the planet; the the crater, Sector Zero and the Crater Edge.

The known planet is almost completely covered in water, except for a few islands, and features a variety of submerged biomes. The Aurora is located a few meters above the surface, in relatively shallow water.

The planet features a full ecosystem of flora and fauna, as well as having two moons, one being very close to the planet, causing frequent solar eclipses. However, this is only a very small area of the planet, located in a dormant volcanic crater, approximately 2km in diameter. The rest of the known ocean is referred to as the Crater Edge, it is extremely deep and nearly devoid of life, supporting only microscopic life forms, and Ghost Leviathans. It is unknown whether any similar areas of life exist elsewhere on the planet.

Precursor and PDA data make note of high thermal activity from the planet's core. This is evidenced by the Inactive Lava Zone and Lava Lakes, respectively. The Precursors took advantage of this feature, installing the Alien Thermal Plant within the Lava Castle, which allowed the generator to harness the planet's natural thermal energy.


Around 1000 years ago, The Almanac arrived at Planet 4546B, setting the planet up as a research outpost in order to find a cure for the Kharaa.

Following Ryley's return to Alterra, the aforementioned company installs The Vesper to orbit 4546B to harness it's natural resources and conduct research on the secrets the planet holds.

Data Bank Entry

4546B Environment Scan
  • Category 3 Ocean planet
  • Oxygen/Nitrogen Atmosphere
  • Extensive biodiversity

Safety Warnings:

  • May support leviathan class predators
  • Water contaminated with high levels of foreign bacteria
  • Planet is beyond federation space, rescue unlikely

It is not recommended to explore this environment without hazardous material suits and extensive support apparatus.


  • Planet 4546B is most likely located in the Habitable Zone, a section in a planetary system where life can thrive.
    • However, given the size of the planet's parent star, 4546, seen during the loading screen, it is not possible for Planet 4546B to be within the Habitable Zone, but the ingame star appears to be closer than in the loading screen. This is most likely a developer oversight, or purely artistic representation.
    • Another likely explanation is that the star 4546 is actually behind the viewer's perspective, out of the image.
  • Planet 4546B may be based on the real-life planet Gliese 1214B, as both appear similar in appearance, and are both "water worlds". 
  • Planet 4546B may be rotating diagonally because the star 4546B appears to rise in the North-East and set in the South-West, somewhat like Uranus' 97 degree tilt (Assuming the magnetic field is the same as Earth's).