BobHegwood wrote:I just know that I'm going to be sorry I asked this, but the add-on does not work on my system (see specs below) and I just thought I'd ask what we need in order to use spice kernels.
In fact, what ARE spice kernels? Can this be explained in terms that the Brain-Dead can understand? When I install your complete revision, I don't even see Dawn listed as being contained in the Solar System.
Thanks, Brain-Dead
Well spice kernels are basically big lookup tables for solar system bodies. They span a specific period and can contain several bodies.
Like xyz files positions are stored with respect to a specific body, like a planet or the sun.
These data files, can be downloaded from NASA, and are available and maintained on the NAIF FTP-site (ftp://naif.jpl.nasa.gov/pub/naif/). By using these kernels you achieve the biggest accuracy possible. In fact, NASA uses these files to plan their missions, so you're working with the same data the NASA scientists work with.
I configured my celestia to use spice kernels for all bodies, like planets and moons (and the sun, which is probably the cause that the addon won't work on your system).
You can use this code for the sun (sol.stc in Celestia\data):
Code: Select all
Barycenter "Solar System Barycenter:SSB" {
RA 0
Dec 0
Distance 0
}
0 "Sol:Sun"
{
OrbitBarycenter "Solar System Barycenter"
CustomOrbit "vsop87-sun"
SpectralType "G2V"
AbsMag 4.83
RotationPeriod 609.12 # 25.38 days
Obliquity 7.25 # correct orientation relative to ecliptic
EquatorAscendingNode 75.77
RotationOffset 23.00 # standard meridian
Texture "sun.*"
}
You don't need a special version of Celestia to use this.
