Overview
The Record
Tarn anchors a second guarded passage through the inner Shatter. Its beacons and patrols can open an alternative route when the principal crossing is unusable, but the passage remains useful only while few vessels know where to look for it.
Tarn’s inhabitants live in buried fortified holds with independent air, water, and power reserves. Isolation is expected rather than exceptional. Armor, pressure doors, beacon parts, and life-support stores are all treated as infrastructure because nearly every replacement arrives through the same debris field the garrison defends.
A local garrison council governs daily law. Caldrin controls beacon solutions, passage policy, and external defense, and its name gives a passage order legal force. Hold and formation signs remain local; Tarn has no sovereign crest.
An Occulter protects knowledge of the second route, while Dawn rites attend each corridor’s reopening and the return of patrols. Secrecy limits Tarn as much as it protects it: the settlement cannot advertise the passage, expand ordinary traffic, or turn its strategic position into an open port without destroying the reason Caldrin maintains it.
Political Relationships
Standing
Standing at a Glance
- Political Status
- Chartered Dependency
- Civilization Status
- Inhabited
- Heraldic Standing
- No Unified Mark
- Principal Power
- Caldrin
Tarn is a Caldrin-administered defensive settlement. Its garrison council manages daily law, holds, patrols, and local stores. Caldrin controls beacon solutions, passage policy, external defense, and the warrants under which vessels use the second route. Garrison and hold signs are local; Caldrin’s name is the recognized authority on passage orders.

Physical Characteristics
Ground and Sky
- Diameter420 km
- Mass0.0000098 Earth masses
- Gravity0.02 g
Tarn is airless. Its 290,000 inhabitants live in buried fortified holds with independent air, water, and power reserves designed for long isolation. Surface patrols and beacon crews require full pressure protection, and each hold is compartmented so one breach does not compromise the settlement.
Orbit and Time
Path Around Oranth
- Orbital Order670
- Orbital Radius10,100,000 km
- Orbital Period119.793 days
- Rotation15.8 hours
- Inclination5.1 degrees
- Eccentricity0.052
Tarn rotates every 15.8 standard hours. Moving debris produces irregular eclipses and sensor shadows whose timing matters more to defense than sunrise. Garrison clocks therefore track beacon windows, patrol sectors, and predicted debris movement rather than the exterior light cycle.
Culture
The Twofold
Tarn’s garrison retains an Occulter to protect knowledge of the second passage and the beacon pattern that opens it. Dawn rites mark reopened corridors and returned patrols. Practice serves the route’s operation: concealment must keep the passage restricted without preventing authorized crews from finding it.
Travel
Travel Notes
Approach only on a current Caldrin beacon solution and remain inside the assigned corridor. Unscheduled landings are treated as threats. Debris movement can cancel an authorized window without notice, and a prior solution is not evidence that the same route remains open.
