Building planets with Celestia

[Emaline Dayne]

I work on another proprietary project that deals with student creation of solar system models in Washington.

Is anyone building a component for Celestia that would allow users to build planets (i.e., create them, set their orbit, set their mass, density, etc.) and then view them?

Our goal is to have students build 3d models of the solar system and then test them. Your software is awesome, but will anyone be creating a component that will allow users to build a solar system from scratch?

Thanks...I would be interested to know.

[Guest]

Try Rassillons cluster generator...it also adds planets. You have to use the texture pack.

[selden]

Emaline Dayne,

What do you mean by "test them"?

Celestia doesn't implement gravity, so it can't show how orbits change with time due to different initial conditions. Objects follow the orbits specified, no matter how non-physical they are.

I presume you're aware of the various "accretion model" generators for hypotheticsl planetary systems. Several are available on the 'net. Jim Burrows was hoping to modify his to generate SSC files, but that hasn't happened yet.

http://www.eldacur.com/~brons/NerdCorner/StarGen/StarGen.html

[ElPelado]

there is a program called Orbiter Xplorer. there you can put imaginary planets or the solar system planets and make the orbit a star, to see how the gravity affects their orbits.
the program includes many examples, on of them is about the sun and earth, and what can happen if another star comes near our system, and you see that the earth orbit is modified.

look for it.

[Emaline Dayne]

by testing a model we mean that

1) a student creates a model of the solar system based on a hypothesis to answer a question (e.g., Can you model earth's seasons?).

2) the student provides the needed data (orbit, planetary mass, diameter, etc.)

3) the student can then "watch" the simulation to verify its correctness

-emaline

[selden]

Emaline,

Of course, you had to pick an example that Celestia can't show completely. It can easily show the how the seasonal illumination changes due to the tilt of the axis and that the overall temperature changes due to the eccentricity of the orbit. Getting it to show different groundcover at different times of the year is more of a challange, though.

What simulation software are you currently using?
Is it publicly available? Commercial/Share- or Freeware?

[marc]

Jim Burrows was hoping to modify his to generate SSC files, but that hasn't happened yet.

http://www.eldacur.com/~brons/NerdCorner/StarGen/StarGen.html

I modified this program (stargen) a while ago to create solar systems (as zipped ssc files) for all the stars in Celestia. see the link below. It also creates moons and there is a texture pack much like rassilons generator.
Im still working on stargen, (its being modified to output to an SQL database instead).

[marc]

I was looking at Jims site and decided to have a play with stargen agian. The source package now has code that outputs *.ssc files.

Here is a sample of the output.

Code: Select all

"p4" "ALF Cen B"
{
   Texture "mars.jpg"
   Radius 6375.7
   Mass 1.0

   Color   [ 1 0.75 0.7 ]
   HazeColor [ 1 1 1 ]
   HazeDensity 0.45

   Atmosphere {
      Height 30
      Lower [ 0.8 0.6 0.6 ]
      Upper [ 0.7 0.3 0.3 ]
      Sky [ 0.83 0.75 0.65 ]
   }

   EllipticalOrbit {
      Period            0.94  # years
      SemiMajorAxis     0.920  # AU
      Eccentricity      0.002
      Inclination       0.0
      AscendingNode     0
      LongOfPericenter  0
           MeanLongitude 0
   }

   RotationPeriod    15.78
   Obliquity         16
   Albedo            0.242
}


[Apollo7]

hey, just addint my two cents, I use Celestia to impliment the solar systems I create in Excel. It's pretty nifty for that, Rassilons cluster generator is cool for more Quick and Dirty systems, and it can generate alot of them. Even if you don't have a program to do it for you its easy enough to get the formulas and do it by hand. Cheers.