Kerbol System

Orbits of planets and dwarf planets

All celestial bodies orbiting Kerbol with the sizes to scale

Comparison of the radii

The Kerbol System is the planetary system in which Kerbal Space Program takes place. It has Kerbol as the central body which is orbited by 5 planets and 2 dwarf planets. Only Kerbin and Laythe have an oxygen atmosphere and only Kerbin hosts life.

With the outermost dwarf planet Eeloo it reaches up to 113 549 713 200 m (about 113.5 Gm or 0.76 AU) out into space. Compared to our Solar System it is a very small system, as Earth's periapsis (or more specific perihelion) is about 147 Gm (or 0.98 AU) and thus outside of Eeloo's orbit.

It is difficult to determine if or where the Kerbol System has an edge. Kerbol itself has a non relativistic escape velocity, so it is possible to escape Kerbol. But it is not actually possible to escape Kerbol's gravitational pull since the sphere of influence is infinite. Although real-world gravity for any body technically expands into infinity, it does so only for Kerbol in KSP, so it's unclear if this property can be used to determine where the edge is.

Graphical comparison of the main celestial bodies in the Kerbol System (sizes to scale)

Old System in KSP1

Kerbol
Moho
Eve	Gilly
Kerbin	Mun	Minmus
Duna	Ike
Dres
Jool	Laythe	Vall	Tylo	Bop	Pol
Eeloo
(Sizes and distances not to scale)

Main celestial bodies in the Kerbol System in KSP2 (sizes not to scale)

Relation to the Solar System

Kerbol system	Solar system
Kerbol	Sun
Moho	Mercury
Eve	Venus
Kerbin	Earth
Duna	Mars
Dres	Ceres
Jool	Jupiter
Eeloo	Pluto

Planet from the Kerbol System are defined from a few characteristics:

Characteristic	How the value was chosen
gravity at sea level	hand-picked, followed by a conversion from single to double precision (e.g. gravity on Eve is 1.70000004768372g instead of 1.7g)
radius	hand-picked, loosely a tenth the radius of its solar counterpart for Moho, Eve, Kerbin, Duna and Jool
rotational period	hand-picked or tidally locked, except Kerbin (21599.91201454015) and Duna (65517.859375)
orbit semi-major axis	an eleventh the one from its solar counterpart, except for Eeloo, computed in single precision floating point arithmetic
eccentricity	hand-picked, close to solar one for Moho, Jool and Eeloo
mean anomaly at epoch	hand-picked (radians), often 3.14
inclination	hand-picked (degrees), close to solar one for Moho and Eve
longitude of ascending node	hand-picked (degrees)
argument of periapsis	hand-picked (degrees)

See also

• Kerbol System/Table for a table of all objects