HX-18 is one of the twenty systems charted by Taisa Hanako while she commanded the YSS Elfin Princess in YE 30.

This star system is colonized by an unknown military dictatorship. It is theorized that the inhabitants are descendants of the original human colonists who also colonized Nepleslia. All inhabitants wear masks to filter out the Carbon Dioxide from the air. Without the masks, their atmosphere would at be fatally high levels of CO².

Star Army ships are ordered not to travel through this system until further notice.

• Type M8 V Red Dwarf
• Radius 2.70 x 10⁵ km (0.39 x sol)
• Mass 5.47 x 10²⁹ kg (0.28 x sol)
• Temperature 2200 K
• Luminosity 2.11 x 10²⁵ W (0.06 x sol)

• Type Rock Planet
• Orbital Radius 1.91 x 10⁷ km (0.13 AU)
• Period 7.60 x 10^² hours (0.09 earth years)
• Gravity 16.01 m/s² (1.64 x earth)

• Type Terrestrial World
• Orbital Radius 3.76 x 10⁷ km (0.25 AU)
• Period 2.10 x 10³ hours (0.24 earth years)
• Physics Small iron/silicate
• Hydrosphere 16 % water, 21 % ice
• Atmosphere Thin toxic
• Biosphere Microbes, fungi, animals
• Civilization Colony
• Special Wreckage of a crashed starship

• Type Small iron/silicate
• Radius 3015.99 km (0.47 x earth)
• Surface Area 1.14 x 10⁸ km²
• Land Area 9.72 x 10⁷ km² (0.65 x earth)
• Mass 6.43 x 10²³ kg (0.11 x earth)
• Density 5.60 g/cm³ (1.01 x earth)
• Composition 30.3% oxygen, 30.1% iron, 14.0% aluminum, 12.0% silicon, 10.0% other metals, 3.6% other elements

• Gravity 4.70 m/s² (0.48 x earth)
• Escape Velocity 5.32 km/s
• Rotation
• Period 27.54 hours
• Axis Tilt 20.91 °

• Water 16 %
• Ice 21 %

• Type Thin toxic
• Pressure 57.54 kPa (0.57 x earth)
• Composition 44.3% argon, 31.7% carbon dioxide, 24.1% oxygen, trace other gases

• Type Cool
• Min Temp 186 K (-86 °C)
• Avg Temp 289 K (15 °C)
• Max Temp 360 K (87 °C)

• Chemistry Carbon
• Lifeforms Microbes, fungi, animals

• Type: Colony
• Population: 378,000
• Society: Military Dictatorship
• Tech Level: Spacefaring (orbital spacecraft, cybernetics, laser weapons)

• Wreckage of a crashed FTL starship