Sunday, February 3, 2013

C/2012 DA14 in Celestia

Near Earth Asteroid 2012 DA14 simulated in Celestia at the time of closest approach. Disappointingly, the simulated distance is out 10 fold (click to embiggen).

While we are waiting for the Near Earth Asteroid 2012 DA14 to come, I thought I'd set up a little Celestia file so you could play with it.

Unfortunately, like many planetarium programs, Celestia doesn't handle extreme close approaches well. Using the latest Minor Planet Center data, it places the asteroid at around 300,000 Km away at closest approach, instead of around 30,000 Km.

I've tried creating XYZ files for it, which should more accurately represent the orbit, but I'm obviously doing something wrong as they make the situation worse.

Anyway, here's the current file, have a play with it anyway.

As usual, copy the code below and save as it as a text file 2012DA14.ssc in the Celestia extras folder.
======================2012DA14.ssc=============================
"2012 DA14" "Sol"

#Data from MPC http://cfa-www.harvard.edu/iau/MPEph/MPEph.html
#Epoch 2013 Apr. 18.0 TT = JDT 2456400.5                 MPC
#M 231.02518              (2000.0)            P               Q
#n   1.13512585     Peri.  195.60602     +0.95125404     +0.28828263             T = 2456514.12161 JDT
#a   0.9101369      Node   146.99587     -0.25703914     +0.93743151             q =     0.8285228
#e   0.0896723      Incl.   11.60623     -0.17043071     +0.19523136    Earth MOID = 0.00007 AU
#P   0.87           H   24.4           G   0.15           U   1
#From 196 observations at 2 oppositions, 2012-2013, mean residual 0".42.

{
    Class "asteroid"
    Mesh   "ky26.cmod"
    Texture "asteroid.jpg"
    Radius  0.02 # maximum semi-axis
    MeshCenter [ -0.000718 -0.000099 0.000556 ]

    InfoURL "http://en.wikipedia.org/wiki/2012_DA14"

    EllipticalOrbit
    {
    Epoch                  2456400.5      # Epoch 2013 Apr. 18.0 TT = JDT 2456400.5
    Period                 0.87           # P
    SemiMajorAxis          0.9101369      # a
    Eccentricity           0.0896723      # e
    Inclination           11.60623        # Incl.
    AscendingNode         146.99587       # Node
    ArgOfPericenter       195.60602       # Peri
        PericenterDistance      0.8285228     # q
        MeanAnomaly           231.02518       # M
    }

        #One or other of these lines, with XYZ data, should have given a more
        #accurate orbit, they didn't
        #SampledOrbit "2012_DA14.xyz"
        #SampledTrajectory { Source "2012_DA14.xyz" }

    RotationPeriod 0.9

    Albedo 0.15

}
=============================================================

0 comments:

Post a Comment

 
Copyright © . Reflection Images - Posts · Comments
Theme Template by Blogger · Powered by Blogger