Teshuun

Teshuun, formally designated Craehlil VII, is the seventh and outermost major planet of the Craehlil System in the Orion Arm of the Milky Way Galaxy, orbiting Craehlil at a semi-major axis of 14.12 AU. Classified as a rogue ice world, Teshuun is infamous for its erratic, highly elliptical orbit and its passage through the system’s distant debris fields. The planet’s surface is dominated by thick layers of frozen nitrogen, methane, and ammonia, mantled over a silicate-ice mantle and a presumed rocky core. Glacial fractures, deep impact scars, and migrating cryovolcanic vents mark a world in constant flux, with tidal and radiogenic heating occasionally triggering geyser eruptions and atmospheric haze events. Teshuun’s orbit brings it periodically close to the system’s heliopause, where solar influence wanes and interstellar cold prevails, plunging the planet into extended periods of deep freeze and atmospheric collapse.
Though uninhabitable by any known biosphere, Teshuun serves as both a scientific curiosity and a marginal resource frontier for the system’s syndicates and exploration enclaves. Historical records suggest Teshuun was once a captured object, its present instability a legacy of ancient gravitational encounters—possibly with the gas giant Ravla or a now-absent system member.

Teshuun

Astrographical Information

Galaxy

Milkyway

Galactic Arm

Orion

System

Craehlil System

Orbiting

Craehlil

Orbital position

Seventh Planet

Orbital Distance

14.12 AU (2,115,464,400 km)

Orbital characteristics

Aphelion

16.43 AU (2,460,236,000 km)

Perihelion

10.97 AU (1,643,229,700 km)

Semi-major axis

14.12 AU (2,115,464,400 km)

Eccentricity

0.244

Orbital period (sidereal)

18,679.4 days

Average orbital speed

3.5 km/s

Mean anomaly

17.4°

Inclination

• • 2.9° – Craehlil's equator;

• • 2.5° – invariable plane;

• • 4.3° – J2000 ecliptic

Longitude of ascending node

218.1°

Time of perihelion

9,330.7 days

Argument of perihelion

129.4°

Moon(s)

4

Physical Information

Diameter

9,312 km (5,785.6 mi)

Mean radius

4,656 km (2,892.8 mi)

Equatorial radius

4,662 km (2,896.6 mi)

Polar radius

4,650 km (2,889.0 mi)

Flattening

0.0026

Circumference

• 29,273 km; equatorial

• 29,201 km; meridional

Surface area 272,550,000 km²

• Land: 272,550,000 km² (frozen ices & silicate crust)

• Water: 0 km² (trace clathrate deposits)

Volume

4.22 × 10¹¹ km³

Mass

1.1 × 10²⁴ kg

Mean density

1.43 g/cm³

Surface Gravity

4.2 m/s²

Moment of inertia factor

0.336

Escape velocity

4.8 km/s

Synodic rotation period

33.2 Hours

Sidereal rotation period

32.7 Hours

Equatorial rotation velocity

90.2 m/s

Axial tilt

27.2°

Axial Precession

41,300 years (influenced by orbital eccentricity and cryovolcanic mass shifts)

Albedo

• 0.67 geometric

• 0.52 Bond

Temperature 21–74 K

Surface Temperature

• -249°C (-416°F) Min

• -213°C (-351°F) Mean

• -133°C (-207°F) Max

Surface absorbed dose rate

0.3 μGy/h

Surface equivalent dose rate

0.5 μSv/h

Apparent magnitude

+5.7" to +9.2"

Absolute magnitude (H)

7.81

Atmosphere

Surface pressure

0.021 kPa; ~0.0002 atm (tenuous nitrogen-methane envelope)

Composition by volume

• 72.3% Nitrogen

• 19.4% Methane

• 4.2% Ammonia

• 2.6% Carbon monoxide

• 1.0% Argon

• 0.5% Trace volatiles (ethane, hydrogen cyanide, acetylene, seasonal haze)