Unknown

Summary
The land-based cousin to Strange Sea worlds, these planets are completely random in terms of biomes and ores. They generate in layers, each layer being from a different planet type and having different ores. Even their cores are random!

Codex Description
Unknown interference prevents scanning of the planet surface. Proceed carefully. Potentially Lethal!

Something here is blocking our scanners, leaving this planet's composition essentially unknown. Potentially Lethal!

Unknown readings are confusing our scanners. I can glean nothing useful from them. Potentially Lethal!

Appearance
Unknown planets can have nearly any color in the preview window, and generate like most non-ocean planets on the surface. The surface will generally be one main biome with a sub biome or two. As you dig farther down into other layers, the background and ambience will abruptly change along with the blocks and ores present. The underground biomes are typically from other planet types. The planet's core is also often a different liquid other than Lava, and this liquid also replaces the lava pools at the core level.

Notable Features
Just like these planets can feature any biome, surface or underground, they can also have any ore. They can become valuable sources of Densinium and other biome-exclusive ores, especially if the planet is less dangerous than the biome where one would normally find the ore.

Valuable biomes can also be the main biome. Huge Eden worlds full of labs to loot with Densinium waiting below the surface are entirely possible.

Dangers
These planets can be anywhere from tier 4 to 10, and can have nearly any planetary effect. Be ready to quickly beam back up to get the right protective gear. The tier can also be a threat in itself.

Digging from layer to layer can also present hazards. One of these is falling, as sometimes a large gap generates at the top of a layer, with some lower layers being an entirely different surface biome. This can create a sky-spanned space in-between. Be careful when digging. Some can even generate ocean-like biomes beneath their surface, such as a Magma biome, so be very careful if you're using a mining laser, as they remove the background as they dig, and can release lava into your tunnel.

Rarely, on very large planets, you may beam down underground in a huge cavern. It will take a very long time to dig back up if this happens, and unless the planet has good ores down there, it might be best to use /admin to be able to beam up regardless of height.

There may be others as well. Please add them as you find them.