Grant Hutchison's Contributions for Celestia v1.3.0

0: Introduction.
1: Saturn's moons.

See also:

• Grant Hutchison's Contributions for Celestia
  • Nearby Stars closer than 25LY for Celestia v1.3.1
  • Celestia's Invisible Object (new for v1.3)
  • Placing objects at defined locations on planetary surfaces
    (Modified for use with Celestia v1.3)
  • Zubrin Statites to Terraform Mars
  • Corrections for Celestia v1.2.5

0: Introduction.

Celestia 1.3.0 corrects a number of problems that existed in 1.2.5 and earlier versions:
1. Textures no longer need to be reversed north-to-south before being applied to 3ds mesh objects.
2. Orientation of all texture maps has been corrected.
3. RotationOffset has been corrected for all major bodies.
4. Gaspra, Ida and Eros have been provided with appropriate texture maps, and correct orbital elements for their encounters with spacecraft (the first NEAR-Shoemaker encounter only, in the case of Eros).
5. Venus now has separate surface and cloud maps.
6. Saturn's rings have been corrected.

Most of the corrections detailed for version 1.2.5 are therefore not required and potentially in error when applied to 1.3.0. Below are some additions specific to 1.3.0 - do not use them with earlier versions.

• saturnmoons-130.zip (252KB, 17Apr03)

  Archive:  saturnmoons-130.zip
  
    Length     Date   Time    Name
   --------    ----   ----    ----
     125599  02-04-03 02:42   models/epimetheus.3ds
     125599  02-04-03 02:34   models/janus.3ds
     125599  02-03-03 19:53   models/prometheus.3ds
          0  04-15-03 19:12   models/
          0  04-15-03 19:22   textures/lores/
       3216  04-15-03 19:22   textures/lores/epimetheus.jpg
       3985  04-15-03 19:22   textures/lores/janus.jpg
       3271  04-15-03 19:22   textures/lores/prometheus.jpg
          0  04-15-03 19:20   textures/medres/
      13676  04-15-03 19:20   textures/medres/epimetheus.jpg
      16569  04-15-03 19:18   textures/medres/janus.jpg
      12876  04-15-03 19:19   textures/medres/prometheus.jpg
          0  04-15-03 19:20   textures/
       2630  04-15-03 20:11   SaturnMoons-readme.txt
   --------                   -------
     433020                   14 files
  

  This file should be unzipped in your Celestia \extras directory. It provides shape models and textures for three inner moons of Saturn, adapted from public domain data and images provided by Phil Stooke at his Cartography of Non-spherical Worlds website http://publish.uwo.ca/~pjstooke/plancart.htm and his Small World Atlas website http://www.ssc.uwo.ca/geography/spacemap/contents.htm

  I generated the 3ds mesh objects and modified and applied the texture maps. Smoothing of the resulting objects was done by "Praesepe". All of these satellites depart markedly from simple elliptical orbits - Janus and Epimetheus interact strongly with each other during close approaches, as do Prometheus and the satellite Pandora. The orbits provided in Celestia's minormoons.ssc are correct for January 2000, but will be significantly in error at other dates. However, all these moons are in synchronous rotation with their orbital periods, so it adds realism if the shape models are rotated to align their prime meridians with Saturn.

  To display them optimally in Celestia you should edit the texture and mesh definitions, and also add the necessary RotationOffsets to minormoons.ssc, as noted in CAPITAL LETTERS in the text that follows:

  However, if you have not previously edited minormoons.ssc, and therefore have no changes you wish to preserve, you may prefer to simply copy the following version on top of the original file in the \extras folder - this will automatically make all necessary changes.

• minormoons.ssc (17KB, 17Apr03)

  ---

  
  "Prometheus" "Sol/Saturn"
  {
          Texture         "prometheus.jpg"        # CHANGE THIS LINE
          Mesh            "prometheus.3ds"        # CHANGE THIS LINE
          Radius          50.1
  
          EllipticalOrbit
          {
          Period          0.612986
          SemiMajorAxis   139350
          Eccentricity    0.0023
          Inclination     0.000
          LongOfPericenter 32.879 # J2000.0 
          MeanAnomaly     22.695  #
          }
  
          RotationOffset  55.6                    # ADD THIS LINE
  
          Albedo 0.6
  }
  
  # ...Pandora is here in original file
  
  "Epimetheus" "Sol/Saturn"
  {
          Texture         "epimetheus.jpg"        # CHANGE THIS LINE
          Mesh            "epimetheus.3ds"        # CHANGE THIS LINE
          Radius          59.5
  
          EllipticalOrbit
          {
          Period          0.694590
          SemiMajorAxis   151422
          Eccentricity    0.0205
          Inclination     0.337   #
          AscendingNode   149.880 #
          ArgOfPericenter 86.905  # J2000.0
          MeanAnomaly     192.354 #
          }
  
          RotationOffset  69.1                    # ADD THIS LINE
  
          Albedo 0.5
  }
  
  "Janus" "Sol/Saturn"
  {
          Texture         "janus.jpg"             # CHANGE THIS LINE
          Mesh            "janus.3ds"             # CHANGE THIS LINE
          Radius          88.8
  
          EllipticalOrbit
          {
          Period          0.694590
          SemiMajorAxis   151472
          Eccentricity    0.0073
          Inclination     0.168   #
          AscendingNode   120.557 #
          ArgOfPericenter 43.066  # J2000.0
          MeanAnomaly     79.973  #
          }
  
          RotationOffset  243.6                   # ADD THIS LINE
  
          Albedo 0.6
  }
  

  ---

  Grant Hutchison April 2003

Contents

0: Introduction.
1: Saturn's moons.

• Grant Hutchison's Contributions for Celestia
  • Nearby Stars closer than 25LY for Celestia v1.3.1
  • Celestia's Invisible Object (new for v1.3)
  • Placing objects at defined locations on planetary surfaces
    (Modified for use with Celestia v1.3)
  • Zubrin Statites to Terraform Mars
  • Corrections for Celestia v1.2.5

• Selden's List of Celestia Resources

---

The content of this Web page was provided by Grant Hutchison.

This Web page is maintained by Selden Ball at Wilson Lab.
Please send any comments or corrections to seb@lepp.cornell.edu