Thera

Thera
Type: Terrestrial (Poseidonal)
Primary Star: M6V (Red Dwarf)
Gravity: 1.3 g
Diameter: 17,477 km
Atmospheric Pressure: .9 atm
Atmospheric Composition: 79% carbon dioxide, 20% oxygen
Surface Temperature (Mean): 12 C
Day Length: 28 Hours
Orbital Period: 394
Satellites: None
Gate Access: Martian Gate
Notes: Planetary Rings, Impressive Natural Terrain, Alien Archaeological Traces, High Population of System Bodies
Thera should be an unremarkable planet. An oceanic terrestrial, it has a rocky core and had large volumes of ice in the crust, which are heated by a combination of proximity to the star, and complex tidal forces from the multitude of other planets in it's system. This makes it an unusual type of planet, with a deep global sea covering 85% of the surface, and a large number of icebergs and icemounts dotting this surface, the only "landmass" series of volcanic island chains which breach the shallowest portions. Simple chemosynthesis using microbes live in the depths, hugging geologic events caused by this tidal activity. Tidal forces also seem to have destroyed at least one moon of Thera, forming a distinct planetary ring around the planet. In terms of habitability, Thera is cool, and while the temperature is comfortable, the atmosphere cannot be breathed unaided, and the gravity level is outside normal transhuman comfort. There is little of value here for many colonists and corporate interests, and it should have been relegated to an obscure planetary science outpost.
That is until researchers found the "Labyrinth". Also known as "The Maze", this massive, vaguely circular structure dominates Thera's largest landmass, with an interior that covers hundreds of square kilometers. Up close, it is a maze-like structure which seems almost carved out of a plateau of black volcanic rock - with walls over a kilometer high. The width of the path is relatively narrow, about 6 meters across. The height and width are uniform throughout. Aerial surveillance has given a rough outline of the nature of the maze and can roughly theorize paths, but the structure seems deliberately shaped to play tricks on the eyes and minds of viewers from above, with even predictive AGI having trouble with some images. Close overflight is hampered by turbulent winds which form above the maze. What is verifiable that there is some kind of scanning resistant structure at the heart of the Labyrinth - but what lies under or inside it is unknown. It is considered a great mystery of Gatecrashing, as due to unpleasant conditions of Thera, no one has yet been able to navigate completely to the center. Pathfinder is eager to turn the Maze into a tourist attraction, and thus is is paying highly for explorers to attempt to map it an uncover its secrets, but other hypercorps seem strangely wary of the structure. The lack of completing the maze has caused a font of rumors to erupt on ExploreNet; that the featureless expanse of the maze drives men mad, that the aerial view is a fabled "Basilisk" - and that staring at it too long will give you an obsession to find the center, that despite appearing solid the maze actually shifts and changes over time which is why it cannot be mapped, that TITAN bots lurk in the maze - also trying to seek the center and will kill those who get in their way, or that the aliens who assembled this massive structure left some kind of construct as a guardian. The only other more frequent rumors are what exactly lies at the center of the maze. Is is an alien species last record - a will and testament? Did some species achieve a controlled singularity, leaving behind the maze as a path to ascension? Is is a pilgrimage for some lost, long-dead alien religion? Is it a secured site, storing something dangerous or unpleasant and thus difficult to arrive at? Only time will reveal the center of the Labyrinth. The Thera gate lies on the rim of a volcanic caldera which has since submerged and gone extinct, on an island chain several kilometers from the Maze.

[Sidebar] MINOTAURS
[The following is a short burst QE text from Thera]
From: NECRONOMICON Dead Drop - Thera Gate - Codename: ARIADNE
To: <encrypted>
Confirmed Minotaur eventuality. Non-TITAN Origin. Possible ETI. Non-ELDRITCH WARD. Tap CLOSE CONTACT and BERSERKER VOID. # unknown, more than one Minotaur probable. OZMA involvement/knowledge unknown, assumed. Pathfinder knowledge minimal. ExploreNet knowledge minimal. Prep Erasure Team for Operation THESEUS. Heavy loadout recommended, might need to bring Annie. 2 Sentinels KIA, 1 MIA. Exact operational capabilities: Unknown. DESTROY recommended.
I'm going to go back in and get a closer look.
ARIADNE Out.

(For those interested in Thera, I have written a short scenario about the planet and it's mysterious maze - Live Without Your Sunlight for anyone to try. Feel free to leave comments or observations here.)