Where are all the comets ?

[Cham]

I want more comets ! By default, Celestia is showiing me very few comets (about half a dozen). Where can I find more comets ?

[selden]

Another half-dozen are available individually at http://www.lns.cornell.edu/~seb/celestia/comets.html

I'll investigate what would be needed to generate a more inclusive catalog.

[jestr]

You can find another 314 comets in 'Comets.ssc' of Thomas Guillpain here
http://members.fortunecity.com/guilpain/
or you can get the same 'ssc' from my web site here
http://jestrstuff.0catch.com/extras/extras.html
though you will have to also download the comet1 and comet2 models together with their respective textures from the same site to get them to work.This will mean you get 2 differnt comet models rather than the usual one,cheers Jestr

[Cham]

The first link give me files that doesn't work !

The second link crash my web browser (Safari) !!

No comets yet

[granthutchison]

The first link give me files that doesn't work !

Strange: works for me. I just clicked on the "Comets" link, opened the zip, and dropped comets.ssc into my extras folder - and there they all were next time I opened Celestia.

Grant

[Guest]

There's already a small comets.ssc file (Hale-Bopp comet) in the extra forlder. What have you done with it ?

[Cham]

I examined the file, and there is something strange in it. Hale-Bop is already in the file, but with somthing which look like an error :

"C/1995 O1 Hale-Bo2531.250796243903" "Sol"
{
Texture "asteroid.jpg"
Mesh "asteroid.cms"
Radius 5.00
etc...

Look at its name. There's a big number there. Also, what is this long space within the name ? All comets in this file have this long space in their name !

[granthutchison]

There's already a small comets.ssc file (Hale-Bopp comet) in the extra forlder. What have you done with it ?

Nothing. That file isn't distributed with the Windows version of Celestia. Is it incorporated in installations for other operating systems?

Grant

[selden]

There is a comets.ssc in the CVS archive containing Hale-Bopp, but it's different from what Cham has. I suspect that it got damaged somehow on the system of whoever generated the distribution kit he's using.

See http://cvs.sourceforge.net/viewcvs.py/celestia/celestia/extras/comets.ssc?rev=1.1&view=markup

[granthutchison]

Cham's file is by Thomas Guilpain, and it looks to have been garbled slightly when it was generated from the original Bureau des Longitudes data - some comets have period data mixed into the text of the discoverers' names. The big spaces are present in the original dataset as padding between two column-delimited name fields, which have been treated as a single field during conversion to Celestia format, so the spaces are still visible.

Grant

[Cham]

There is a comets.ssc in the CVS archive containing Hale-Bopp, but it's different from what Cham has. I suspect that it got damaged somehow on the system of whoever generated the distribution kit he's using.

See http://cvs.sourceforge.net/viewcvs.py/celestia/celestia/extras/comets.ssc?rev=1.1&view=markup

This is the file that came with my default installation of Celestia (for OS X). There's only one comet in it (Hale-Bopp) and it's working very well.

Like I said in the previous post, the file I downloaded from a French site appears to be corrupted in some way. I can't have any confidence in it, because the Hale-Bopp is garbled in it. How can I have confidence for the other comets in that file ? The file isn't working on my system anyway. I want those comets, and only real comets (no fictious one, of course). What do you suggest ?

[Cham]

Ok, I made a small successfull experimentation with the French comets file. I copied four comets definitions into my default comets.ssc file. But I had to do some modifications so they can be shown properly in Celestia. In the original file, there is a slash in the name (for example : C/1990). I'm not sure it's a good thing for Celestia, as he's using a slash in the search field. So I replaced them all for a dash (C-1990). Also, a missing comment is necessary in the file so the comet orbit can be shown in Celestia (Class "comet"). I added this comment to all comets definition. Here's an example of a comet definition (with few modification) :

"C-2001 W2 BATTERS" "Sol"
{
Class "comet"
Texture "asteroid.jpg"
Mesh "asteroid.cms"
Radius 5.00

EllipticalOrbit
{
Period 75.39561224643465
SemiMajorAxis 17.79681942595114
Eccentricity 0.940947633329072
Inclination 115.916416049232
AscendingNode 113.354368690213
ArgOfPericenter 142.09490821257
Epoch 2452266.0
}
Albedo 10
}

My modified comets.ssc file is now working properly. I now have total 8 comets showing in Celestia (four original from the default installation + four from the French file).

The problem is : can I have real confidence in the comets definitions from the garbled French file ? I'm afraid to add all those comets. I'm afraid they may be corrupted or unreliable. What is your opinion ? Is there another way out of this problem ?