Astroblog: Comet 67P/Churyumov–Gerasimenko in Celestia

Wednesday, November 12, 2014

Comet 67P/Churyumov–Gerasimenko in Celestia

Comet 67P//Churyumov–Gerasimenko and the Rosetta orbiter rendered in Celestia.

As usual, I have been trying to make a Celestia file for comet 67P.

And failing miserably. I tried to convert the ESA public shape model to celestia 3Ds format and failed miserably. So I ended up using Jack Selden's Rosetta files, with a surface map taken from this thread on the Celestia. The Celestia comet looks nothing like the rubber duck shape of 67P, but until some kind person points me to a pubic Celestia shape model that is what I am stuck with.

I utterly failed to make any of the XYZ orbital files work for me, so I just copied the orbit of Dactyl around Ida. Yes, that's cheating, but after days of frustration I wanted something that works. If you want a stunning Celestia simulation, go here.

As usual, copy the code below and save as it as a text file 67P.ssc in the Celestia extras folder.
==========================67P.ssc=======================================
# Taken from Jack Seldens 67P ssc file
# Created By Ian Shazell, Spacecraft Analyst for Rosetta
# On Behalf of the European space Agency, www.esa.int
# Comet 67P Churyumov-Gerasimenko, Celestia SSC file. www.shatters.net/celestia
#
#
"Churyumov-Gerasimenko" "Sol"
{
    Class "comet"
    Mesh "asteroid.cms"
        Texture "67p720x361.png" # texture from the Celestia forum from John Van Vliet
    Radius 1.98                             # http://forum.celestialmatters.org/viewtopic.php?f=4&t=690
    EllipticalOrbit
    {
        Period                   6.4451441700205338809034907597536
        PericenterDistance       1.2431213
        SemiMajorAxis         3.4632382
        Eccentricity            0.6410523343769
        Inclination            7.04073996
        AscendingNode          50.150595169
        ArgOfPericenter        12.77512076
                MeanAnomaly            -71.72623185
        Epoch                   2456778.5
    }
        Albedo            0.2
}

"Rosetta" "Sol/Churyumov-Gerasimenko"
{
        Class "spacecraft"
        Mesh "rosetta.3ds" # rosetta model http://homepage.eircom.net/~jackcelestia/files/rosetta.zip
        Radius 0.005

        EllipticalOrbit
        {
    Epoch         2449228.2028 # Using orbit of Dactyl around Ida
    Period             0.96534 #
    SemiMajorAxis     25.0     # Why? I can't make anything else work
    Eccentricity       0.13    #
    LongOfPericenter 310       #
    AscendingNode     90       #
                                   #
    Inclination        8       #
        }

        Albedo 0.5
}
======================end 67P.ssc==========================

Labels: 67P, celestia, comet