Metallic Biome

The Metallic Biome is a late-game asteroid biome associated with metal-rich space content and a mix of surface and subsurface resources. It appears alongside Swampy Biome, Marsh Biome, Space Biome, and Magma Biome on the same asteroid type, and it is notable for providing renewable sources of Refined Metal and Raw Mineral through space missions rather than through normal excavation alone.

A trip to the Metallic Asteroid can also return a small set of meteorite resources, including Algae, Slime, Gold Amalgam, and Regolith. In addition, the asteroid may contain guaranteed Natural Gas Geyser, Gold Volcano, and Cobalt Volcano features, with a larger pool of possible additional geysers such as Hydrogen Vent, Iron Volcano, Aluminum Volcano, Copper Volcano, Volcano, Minor Volcano, Chlorine Gas Vent, Infectious Polluted Oxygen Vent, Hot Polluted Oxygen Vent, Carbon Dioxide Geyser, and Carbon Dioxide Vent.

For space missions, the asteroid is listed at a distance of 20,000 kilometers. An efficient rocket setup for resource hauling uses either 4 cargo modules and 2 Liquid Fuel Tanks, or 6 cargo modules and 3 Liquid Fuel Tanks, both of which return 2.22 kilograms of cargo per 1 kilogram of Petroleum fuel when using Cargo Bays. If a Biological Cargo Bay is used instead, the mission can return Smooth Hatches rather than standard cargo resources.

The surface crust is covered in ice, polluted ice, and brine ice exposed to space. These materials begin very cold, around -40°C to -60°C, and are not insulated from the rest of the asteroid. Over many cycles they will eventually melt and much of the resulting liquid is lost to space, so the ice is best treated as a temporary resource rather than a permanent one. On a non-starting asteroid, this melt countdown does not begin until a rocket is first placed in orbit around the asteroid.

That makes the Metallic Biome useful for planned early expeditions. The surface ice can be worth preserving as an initial source of clean water, salt, and cooling. If that is the goal, it is best to delay discovery until several rovers are ready to recover the ice and move it into storage bins deeper inside the asteroid before it is lost.

• The biome is easy to traverse compared with many other space-region environments because it lacks gas, making oxygenation straightforward.
• Its temperature is generally Duplicant-friendly, which reduces the need for heavy thermal preparation.
• The presence of ice makes the biome useful even before mining deeper layers, since the surface materials can support early logistics and cooling.
• Refined Metal sources are especially valuable here, and the increased overheat temperature modifier on steel makes steel infrastructure particularly effective when it is available.