Planetary Data Hub
Welcome to the Sol planetary data hub.
The goal of this hub is to provide users with physical and orbital data about every celestial object in Sol.
Sol is split up into 11 different 'sectors' with each sector hosting their own hub.
[SystemMapImage]
Sectors:
- [Sol]
- [Mercury]
- [Venus]
- [Earth System]
- [Mars System]
- [Jupiter System]
- [Saturn System]
- [Uranus System]
- [Neptune System]
- [Asteroid Belt]
- [Kuiper Belt]
The epoch of the solar system in Sol is 1951-Jan-01 00:00:00.000 UTC. This means the pacific starts facing towards the sun at the beginning of the game and Greenwich England is facing roughly toward the anti-solar point.
Note
Unlike RealSolarSystem which specifies time at the beginning of the BK4 reference epoch and runs time forward, Sol doesn't do this and elects to provide orbital parameters for the instant the system starts.
Sol is intended to be as accurate as possible to our real system. For specific interest on why specific celestials have been added to Sol and why some haven't you can read the blog [Choosing What to Add to Sol]. Generally though celestials were selected off of the following critera:
- Is a major planet: Immediate add.
- Is a major moon: Immediate add.
- Visited by a spacecraft: Highly likely.
- Interesting orbit: Increased likelihood.
- Interesting geographical features: Somewhat increased likelihood.
- Low amounts of imagery data: Highly unlikely.
- Complex shape model: Highly unlikely.
- Mean radius smaller than 450m~: Impossible.
Orbits are defined by 7 different parameters in KSP, these are: semiMajorAxis, eccentricity, inclination, meanAnomalyAtEpochD. longitudeOfAscendingNode, argumentOfPeriapsis and epoch.
You can roughly think of these as doing the following:
- semiMajorAxis (meters): mean distance of the center from the center of the object.
- eccentricity (unitless): the asymmetry Ap and Pe.
- inclination (degrees): the tilt of the orbital plane.
- meanAnomalyAtEpochD (degrees): how far along the orbit the satellite in degrees.
- longitudeOfAscendingNode (degrees): where the orbital plane crosses the ecliptic.
- argumentOfPeriapsis (degrees): where the periapsis is placed in the orbit.
- epoch (seconds): when this state occurs
In reality all of these values shift around due to gravitational influences of their neighbors, but due to limitations in the patched conics system they remain static in KSP. For this reason we split these parameters into mean and instantaneous values.
- semiMajorAxis, eccentricity and inclination are both averaged over a century of data points with a two day time interval between each point.
- meanAnomalyAtEpochD, longitudeOfAscendingNode, argumentOfPeriapsis are instantaneous at the epoch.
- epoch is always 0 unless the data points for the celestial don't exist at 1951-Jan-01.
In KSP celestial objects are defined by the following properties: radius, gravParameter, rotationPeriod, initialRotation.
- Radius (m): is typically the minimum radius of the object, this is to avoid terrain being under 0m sea level as it can cause bugs with terrain rendering.
- gravParameter (m^3/s^2): is the mass of the object multiplied by the gravitational parameter.
- rotationPeriod (rev/s): number of seconds per revolution
- initialRotation (deg): The location of the prime meridian relative to the "0-axis", which is defined by setting all orbital parameters to 0 and drawing a line as SMA approaches infinity.
- isTidallyLocked (boolean): whether the object is tidally locked to its parent. The same hemisphere always faces the parent object.