Infernas as seen from orbit.
Moon of Cyran
Orbital Characteristics
Semi-major axis 15 434 225 m [Note 1]
Apoapsis 15 434 225 m [Note 1]
Periapsis 15 434 225 m [Note 1]
Orbital eccentricity 0
Orbital inclination 0 °
Argument of periapsis 0 °
Longitude of the ascending node 0 °
Mean anomaly 0 rad (at 0s UT)
Sidereal orbital period 11 664 s
3 h 14 m 23.6 s
Synodic orbital period 11666.8 s
Orbital Velocity 8314.4 m/s
Longest Time Eclipsed 2023 s
Physical Characteristics
Equatorial radius 150 000 m
Equatorial Circumference 942 478 m
Surface area 2.8274334×1011 m2
Mass 5.6203156×1020 kg
Standard gravitational parameter 3.7510436×1010 m3/s2
Density 39 755.601 kg/m3
Surface gravity 1.67 m/s2 (0.17 g)
Escape velocity 707.21 m/s
Sidereal rotation period 11 663.592 s
3 h 14 m 23.6 s
Sidereal rotational velocity 80.805 m/s
Synchronous orbit 355.61 km
Sphere of influence 255 203.03 m [Note 1]
Atmospheric Characteristics
Atmosphere present ✓ Yes
Atmospheric Pressure 6.75534 kPa
0.06667 atm
Scale height  m
Atmospheric height 50 000 m
6.7×10-8 atm
Temperaturemin 59.03 °C 332.18 K
Temperaturemax 146.85 °C 420 K
Oxygen present × No
Scientific multiplier
Surface 9.5
Splashed 10
Lower atmosphere 9
Upper atmosphere 8.5
Near space 8
Outer space 7.5
Recovery 7

  1. 1.0 1.1 1.2 1.3 The distances are given from the bodies center not surface (unlike ingame)

Infernas is a hot, rocky moon added in the 'Planet Cyran' planet pack, and the innermost moon orbiting Cyran. It's a hot inferno, hence it's name. Infernas is unique for being a moon that is breaking apart and even using a particle system to show this.

In-Game Description

A moon orbiting way too close to Cyran for comfort. This moon is literally being broken apart by Cyran's gravitational pull. The debris has formed a ring around the large gas giant, and in a few hundreds of thousands of years, that ring will be all that's left of this moon. Visit while you can!

Kerbal Astronomical Society


Physical Properties

Infernas' surface is covered in basalt and sulphur-rich compounds, and its Cyran-facing face has been melted and stripped away to reveal an ocean of lava which will destroy any craft that get too close. The rest of the moon is comprised of rough, basaltic hills while the lava ocean is ringed by high cliffs and contains several islands at its edges that can be safely landed on.


Infernas has a thin atmosphere identical to that of Duna - it was denser in the past but Cyran has pulled most of it away. The remaining atmosphere consists of Carbon Dioxide, Sulfur Dioxide, Argon and Hydrogen, with a surface pressure of 6.755kPa.

Altitude (m) Pressure (Pa) Pressure (atm)
0 6 755 0.067
2 500 5 136 0.051
5 000 3 774 0.037
7 500 2 663 0.026
10 000 1 797 0.018
15 000 716.9 0.007
20 000 241.0 0.002
25 000 91.73 0.001
30 000 32.90 0.000
40 000 4.918 0.000
50 000 0 0.000


Infernas has five biomes, based on distance from the Cyran-facing side:

Infernas Biome Map

Infernas biome map

  • Broken Poles
  • Intact Area
  • Burning Badlands
  • Searing Coast
  • Molten Wasteland


Quote from the author of the Planet Cyran mod:

Ah, Infernas. I actually came up with the idea when reading an article about Triton, a moon of Neptune. Triton's orbit is decaying, and thus it'll eventually drop below the Roche limit and will be pulled apart by tidal forces. That gave me an idea: a moon that is molten on the side facing it's parent planet. I knew that with Kopernicus' particle system I could actually make the moon look like it's breaking apart. Fun fact: Infernas' heightmap is actually made from a highly edited colormap exported from Space Engine, but the rest is built from code only

The White Guardian

Reference Frames

Warp Minimum Altitude
5× 50 000 m (above the atmosphere)
10× 50 000 m (above the atmosphere)
50× 50 000 m (above the atmosphere)
100× 50 000 m (above the atmosphere)
1 000× 60 000 m
10 000× 70 000 m
100 000× 80 000 m


  • According to calculation, for Infernas the Roche limit equals 5769359.55 m. Currently Infernas orbits at roughly twice that distance, but it was placed this far out on purpose: if Infernas would actually orbit at the roche limit, Cyran's pull would be overwhelming that of Infernas, making it impossible to land.
  • According to the author (as stated above) Infernas has been inspired by real-life Triton, which is estimated to suffer the same fate as Infernas, although Tritan has a retrograde orbit and is therefore theorized to be a captured moon, unlike Infernas which has likely formed around Cyran but was pushed inwards by the gravity of the other moons.
  • Infernas is unique for being the only Kopernicus planet or moon to add story to the origin of a nearby ring system and actually using the ring system of it's parent planet, in Infernas' case the particles it emits are dragged into the rings.
  • The 'Planet Cyran' planet pack comes with a flag showing Infernas based off the 'Minimalistic' flag texture by SQUAD.