Thermal Sludge is a resource that is available on Orb Vallis on Venus. Thermal Sludge is needed to build MOA parts, K-Drives, Kitguns, different decorations, and some weapons and Warframe parts.
Thermal Sludge is easy to spot out on Orb Vallis because it spawns in unique containers. These while canisters have a see-through portion in the center, and in the neck, where you can see the sludge, making them stand out against the snow.
They can be found all over the map, but players should start their search at The Pearl on the west side of Orb Vallis. It is worth checking all the named locations, however, such as Temple of Profit, the Grow Site, Temple Fabrication, Enrichment Labs, Spaceport, and Central Maintenance.
All these locations can spawn a lot of Thermal Sludge. Players can also use boosters that can be purchased for Platinum to increase how much Thermal Sludge they pick up each time they find it. The boosters are available from the Market and are worth purchasing if players plan on doing a lot of resource farming.
You can also earn Thermal Sludge from Bounties on Orb Vallis, but this takes so long that it is not worth it. You are better off dash from place to place on your Archwing, farming any containers you see, then resetting by going back to Fortuna before returning to Orb Vallis.