Irradiated Marsh Asteroid guide: aluminium, gold and uranium

AsteroidsMedium2026-10-19

What the Quagmiris Cluster rocket target holds and what to mine first, with three in-game seeds.

The Irradiated Marsh Asteroid is the rocket target three hexes from Quagmiris in the Quagmiris Cluster. The game describes it as a marshy world with significant radiation and an abundance of metal.

Its landing site is a barren chasm. Below it lie marshes, four or more renewable metallic biomes, radioactive biomes, uranium fields and a frozen core. Every sample seed carried two Aluminum Volcano, two Gold Volcano and a Minor Volcano.

Fact	Value
Size	128 × 153 cells
Where you find it	Quagmiris Cluster, three hexes from the start asteroid; reached by rocket.
Biomes	Barren chasm landing site, forest surface, two or more marshes, four or more renewable metallic biomes, three or more radioactive biomes, uranium fields, frozen uranium fields and a frozen core.
Guaranteed vents	A Gold Volcano and an Aluminum Volcano, with a second try of each, Carbon Dioxide Geysers in the uranium fields, and three random geysers.
Peak light and radiation	30,000 lux of sunlight and 125 rads of cosmic radiation at the surface.
World traits	One or two random traits.

Strengths

Two Aluminum Volcanoes and two Gold Volcanoes on every sample seed.
About 400 to 450 tonnes of Aluminum Ore and 560 to 650 tonnes of Gold Amalgam in the rock.
Plenty of Dirt, 1,800 to 2,300 tonnes, for a farm outpost.
Uranium ore, 60 to 95 tonnes per sample seed.

Weaknesses

Radiation and extreme cold in the uranium fields.
Little liquid water: 120 to 165 tonnes of water and a similar amount of polluted water per seed.
A Chlorine Gas Vent rolled on all three sample seeds.

What to target first after landing

Land in the chasm and seal the radioactive biomes.
Start an Aluminum Volcano tap; aluminium conducts heat far better than copper or gold, which makes it the metal for coolers and radiant pipes.
Use the boon rooms (outhouse, wash basin, generator, batteries) the world may spawn for the first crew.
Mine uranium in short trips once lead suits are available.

Surviving the asteroid

Keep the outpost small and supplied from Quagmiris. The chlorine vent and the radioactive biomes are the two places to seal first.

Seed SWMP-C-1234567-0-0-0

Medium Boulders. A Natural Gas Geyser at (46, 30) powers an outpost next to the volcanoes.

Geyser	Cell (x, y)	Average output	Temperature
Minor Volcano	11, 42	509 g/s	1727 ºC
Gold Volcano	92, 33	342 g/s	2627 ºC
Aluminum Volcano	114, 62	318 g/s	1727 ºC
Gold Volcano	43, 45	259 g/s	2627 ºC
Aluminum Volcano	96, 56	227 g/s	1727 ºC
Carbon Dioxide Geyser	18, 14	147 g/s	-55 ºC
Carbon Dioxide Geyser	62, 15	140 g/s	-55 ºC
Chlorine Gas Vent	31, 25	114 g/s	60 ºC
Natural Gas Geyser	46, 30	98 g/s	150 ºC

Seed SWMP-C-2468024-0-0-0

Geodes. A Copper Volcano at (26, 57) joins the aluminium and gold volcanoes.

Geyser	Cell (x, y)	Average output	Temperature
Minor Volcano	90, 102	641 g/s	1727 ºC
Aluminum Volcano	100, 80	344 g/s	1727 ºC
Copper Volcano	26, 57	306 g/s	2227 ºC
Gold Volcano	112, 58	285 g/s	2627 ºC
Aluminum Volcano	95, 48	262 g/s	1727 ºC
Gold Volcano	87, 67	226 g/s	2627 ºC
Carbon Dioxide Geyser	106, 15	152 g/s	-55 ºC
Carbon Dioxide Geyser	51, 15	127 g/s	-55 ºC
Chlorine Gas Vent	39, 70	115 g/s	60 ºC

Seed SWMP-C-31415926-0-0-0

Slime Molds. A Hydrogen Vent at (18, 81) is the local power option.

Geyser	Cell (x, y)	Average output	Temperature
Minor Volcano	87, 86	666 g/s	1727 ºC
Gold Volcano	57, 30	359 g/s	2627 ºC
Gold Volcano	61, 41	321 g/s	2627 ºC
Aluminum Volcano	31, 57	277 g/s	1727 ºC
Aluminum Volcano	105, 59	263 g/s	1727 ºC
Carbon Dioxide Geyser	79, 31	154 g/s	-55 ºC
Carbon Dioxide Geyser	82, 13	117 g/s	-55 ºC
Chlorine Gas Vent	85, 64	107 g/s	60 ºC
Hydrogen Vent	18, 81	88 g/s	500 ºC

Role in the colony

The Irradiated Marsh Asteroid is Quagmiris's aluminium and gold mine and its first uranium source.