COMETS (ssc from MPEC updates)

[Limax7]

Hello group!

I made file comets.ssc from MPEC data. I use my OpenOffice Calc to add data
then I modify file and save to comets.ssc

Data are from 29 Jan 2010 (include all 202 now observable comets)
Include that comets:

Code: Select all

C/2010 B1 (Cardinal)
P/2010 A5 (LINEAR)
C/2010 A4 (Siding Spring)
P/2010 A3 (Hill)
P/2010 A2 (LINEAR)
P/2010 A1 (Hill)
P/2009 Y2 (Kowalski)
C/2009 Y1 (Catalina)
C/2009 W2 (Boattini)
C/2009 U5 (Grauer)
P/2009 U4 (McNaught)
C/2009 U3 (Hill)
C/2009 U1 (Garradd)
C/2009 T3 (LINEAR)
P/2009 T2 (La Sagra)
C/2009 T1 (McNaught)
P/2009 SK280 (Spacewatch-Hill)
C/2009 S3 (Lemmon)
P/2009 S2 (McNaught)
C/2009 R1 (McNaught)
P/2009 QG31 (La Sagra)
P/2009 Q5 (McNaught)
P/2009 Q4 (Boattini)
P/2009 Q1 (Hill)
C/2009 P2 (Boattini)
C/2009 P1 (Garradd)
C/2009 O4 (Hill)
P/2009 O3 (Hill)
C/2009 O2 (Catalina)
C/2009 K5 (McNaught)
C/2009 K4 (Gibbs)
C/2009 K3 (Beshore)
C/2009 K2 (Catalina)
C/2009 G1 (STEREO)
C/2009 F6 (Yi-SWAN)
C/2009 F5 (McNaught)
C/2009 F4 (McNaught)
C/2009 F2 (McNaught)
C/2009 E1 (Itagaki)
C/2009 B2 (LINEAR)
P/2009 B1 (Boattini)
P/2008 Y3 (McNaught)
P/2008 WZ96 (LINEAR)
C/2008 T2 (Cardinal)
P/2008 T1 (Boattini)
C/2008 S3 (Boattini)
C/2008 Q3 (Garradd)
C/2008 Q1 (Maticic)
C/2008 P1 (Garradd)
P/2008 O2 (McNaught)
C/2008 N1 (Holmes)
P/2008 J3 (McNaught)
P/2008 J2 (Beshore)
C/2008 G1 (Gibbs)
C/2008 FK75 (Lemmon-Siding Spring)
C/2008 E3 (Garradd)
C/2008 E1 (Catalina)
P/2008 CL94 (Lemmon)
C/2008 A1 (McNaught)
C/2007 VO53 (Spacewatch)
C/2007 U1 (LINEAR)
C/2007 T5 (Gibbs)
C/2007 S2 (Lemmon)
P/2007 R1 (Larson)
C/2007 Q3 (Siding Spring)
C/2007 N3 (Lulin)
C/2007 M2 (Catalina)
C/2007 M1 (McNaught)
P/2007 H1 (McNaught)
C/2007 G1 (LINEAR)
C/2007 D1 (LINEAR)
C/2007 B2 (Skiff)
C/2006 W3 (Christensen)
C/2006 U6 (Spacewatch)
C/2006 S5 (Hill)
C/2006 S3 (LONEOS)
C/2006 Q1 (McNaught)
C/2006 OF2 (Broughton)
C/2006 K4 (NEAT)
C/2006 K1 (McNaught)
P/2006 F1 (Kowalski)
C/2006 E1 (McNaught)
P/2005 SB216 (LONEOS)
C/2005 S4 (McNaught)
P/2005 S2 (Skiff)
P/2005 RV25 (LONEOS-Christensen)
C/2005 L3 (McNaught)
P/2005 L1 (McNaught)
P/2005 JQ5 (Catalina)
C/2005 EL173 (LONEOS)
P/2004 R1 (McNaught)
P/2004 HC18 (LINEAR)
P/2004 FY140 (LINEAR)
P/2004 F3 (NEAT)
C/2004 D1 (NEAT)
C/2004 B1 (LINEAR)
P/2004 A1 (LONEOS)
C/2003 WT42 (LINEAR)
P/2003 HT15 (LINEAR)
P/2002 X2 (NEAT)
C/2002 VQ94 (LINEAR)
P/2002 Q1 (Van Ness)
P/2001 R6 (LINEAR-Skiff)
P/2000 Y3 (Scotti)
P/1999 XN120 (Catalina)
P/1999 XB69 (LINEAR)
P/1999 U3 (LINEAR)
P/1998 VS24 (LINEAR)
P/1998 U4 (Spahr)
P/1998 U3 (J?ger)
C/1995 O1 (Hale-Bopp)
232P/Hill
231P/LINEAR-NEAT
230P/LINEAR
229P/Gibbs
228P/LINEAR
227P/Catalina-LINEAR
226P/Pigott-LINEAR-Kowalski
225P/LINEAR
224P/LINEAR-NEAT
223P/Skiff
220P/McNaught
219P/LINEAR
217P/LINEAR
215P/NEAT
213P/Van Ness
211P/Hill
203P/Korlevic
202P/Scotti
200P/Larsen
199P/Shoemaker
195P/Hill
187P/LINEAR
186P/Garradd
183P/Korlevic-Juric
180P/NEAT
179P/Jedicke
176P/LINEAR
174P/Echeclus
173P/Mueller
172P/Yeung
169P/NEAT
167P/CINEOS
166P/NEAT
164P/Christensen
162P/Siding Spring
158P/Kowal-LINEAR
157P/Tritton
152P/Helin-Lawrence
150P/LONEOS
149P/Mueller
145P/Shoemaker-Levy
143P/Kowal-Mrkos
142P/Ge-Wang
141P/Machholz
139P/V?is?l?-Oterma
137P/Shoemaker-Levy
136P/Mueller
131P/Mueller
128P/Shoemaker-Holt
127P/Holt-Olmstead
126P/IRAS
123P/West-Hartley
119P/Parker-Hartley
118P/Shoemaker-Levy
117P/Helin-Roman-Alu
116P/Wild
104P/Kowal
100P/Hartley
99P/Kowal
97P/Metcalf-Brewington
94P/Russell
89P/Russell
88P/Howell
82P/Gehrels
81P/Wild
77P/Longmore
74P/Smirnova-Chernykh
68P/Klemola
67P/Churyumov-Gerasimenko
65P/Gunn
61P/Shajn-Schaldach
59P/Kearns-Kwee
54P/de Vico-Swift-NEAT
49P/Arend-Rigaux
47P/Ashbrook-Jackson
44P/Reinmuth
43P/Wolf-Harrington
36P/Whipple
31P/Schwassmann-Wachmann
30P/Reinmuth
29P/Schwassmann-Wachmann
24P/Schaumasse
22P/Kopff
17P/Holmes
14P/Wolf
10P/Tempel
9P/Tempel
8P/Tuttle
7P/Pons-Winnecke
6P/d'Arrest
2P/Encke


And screen from Celestia 1.6

[Limax7]

And all 509 periodic (P<500 years) comets

[Marco Klunder]

Hello Adam,

I downloaded and tried your add-on, but I have some remarks/questions on it:

1.
You choosed to name the comets by a formal notation for comets (number+letter first than a “/”, followed by their more common name). Isn’t it preferred that you can select comets by their more common name? Now it forces the user to recognize all codes first before the more common used names can be selected: e.g. looking for Encke 2P instead of 2p/Enke.

2.
By using the formal notations of comets you introduced the “/” character in the name, resulting in a problem to select it by the [Enter] <name> [Enter] method in Celestia. As soon as the “/” character is typed, nothing can be selected anymore. Also [tabbing] to a specific comet entry containing a “/” character in it’s name result in NOT selecting that specific comet.
In combination with point 1, I suggest that you try to take the layout as used in the standard comets.ssc file.

3.
Are you aware that DIRL also released a comet add-on on the motherlode, containing lots of comets?
It’s available on http://www.celestiamotherlode.net/catalog/show_addon_details.php?addon_id=646
What I should appreciate is a little description about your Add-on in for instance an attached readme.txt, to inform the user about the specialty of this Add-on (probably you can also explain there how it is related to the catalog of comets by DIRL). That can help the user to choose between the two or to integrate, etc.

4.
In your list above, you name for instance Hale-Bopp, but I cannot find it back in your SSC.

5.
Although the standard comets.ssc contains only 4 comets, they contain very famous ones like Halley, Borrelly and Hale-Bopp, which I cannot find back in your Add-on. There are also special meshes used. Is there a specific reason that you skipped those? Is it an idea to integrate both, so replacing just the comets.ssc (after saving the original first of course) can do the job.

Marco

[Limax7]

Hi

Hale-Bopp is in my comets.ssc

Code: Select all

"C/1995 O1" "Sol" {
  Class"comet"
  Mesh"asteroid.cms"
  Texture"comet.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 2413.24834342105000
PericenterDistance 0.908752 
Eccentricity 0.994949 
Inclination  89.2741
AscendingNode 282.7984
ArgOfPericenter 130.5577 
Epoch 2450538.8492 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}

in orginal comets.ssc it's

Code: Select all

"C1995 O1 Hale-Bopp:Hale-Bopp" "Sol"
{
   Class "comet"
   Mesh "asteroid.cms"
   Texture "asteroid.jpg"
   Radius 13

   EllipticalOrbit
   {
   Period          2523.4
   PericenterDistance 0.914142
   Eccentricity      0.995068
   Inclination      89.4300
   AscendingNode   282.4707
   ArgOfPericenter 130.5887
        MeanAnomaly       -0.007
   Epoch       2450520.5
   }

   # Estimate of rotation period from here: http://www.usafa.af.mil/dfp/research/astro/papers/icqpaper.htm
   RotationPeriod  11.47
   Albedo            0.1
}

Diferent is Texture comet.jpg (in my) and asteroid.jpg (in orginal)


I try to change names in comets and delete "/" in names.

Halley, Borrelly and Hale-Bopp are in my comets_all.zip (1P = Halley, 19P = Borelly, C/1995 O1 = Hale-Bopp)

Dirl comets are from 2008-01-11 09:20 but have some that is not in my comets.ssc (like Ikeya-Seki, Hyakutake)

Dirl comets include 161 comets:

Code: Select all

C1965 S1 (Ikeya-Seki)
C1995 O1 (Hale-Bopp)
C1996 B2 (Hyakutake)
C2004 Q2 (Machholz)
2P Encke
4P Faye
6P d'Arrest
7P Pons-Winnecke
8P Tuttle
9P Tempel 1
10P Tempel 2
11P Tempel-Swift-LINEAR
12P Pons-Brooks
13P Olbers
14P Wolf
15P Finlay
16P Brooks 2
17P Holmes
21P Giacobini-Zinner
22P Kopff
23P Brorsen-Metcalf
24P Schaumasse
26P Grigg-Skjellerup
27P Crommelin
28P Neujmin 1
29P Schwassmann-Wachmann 1
30P Reinmuth 1
31P Schwassmann-Wachmann 2
32P Comas Sola
33P Daniel
35P Herschel-Rigollet
36P Whipple
37P Forbes
38P Stephan-Oterma
39P Oterma
40P V\u00e4is\u00e4l\u00e4 1
41P Tuttle-Giacobini-Kresak
42P Neujmin 3
43P Wolf-Harrington
44P Reinmuth 2
45P Honda-Mrkos-Pajdu\u0161\u00e1kov\u00e1
46P Wirtanen
47P Ashbrook-Jackson
48P Johnson
49P Arend-Rigaux
50P Arend
51P Harrington-A
52P Harrington-Abell
53P Van Biesbroeck
54P de Vico-Swift-NEAT
55P Tempel-Tuttle
56P Slaughter-Burnham
57P du Toit-Neujmin-Delporte-A
58P Jackson-Neujmin
59P Kearns-Kwee
60P Tsuchinshan 2
61P Shajn-Schaldach
62P Tsuchinshan 1
63P Wild 1
64P Swift-Gehrels
65P Gunn
66P du Toit
67P Churyumov-Gerasimenko
68P Klemola
69P Taylor
70P Kojima
71P Clark
72P Denning-Fujikawa
73P Schwassmann-Wachmann 3-B
73P Schwassmann-Wachmann 3-C
73P Schwassmann-Wachmann 3-E
74P Smirnova-Chernykh
75P Kohoutek
76P West-Kohoutek-Ikemura
77P Longmore
78P Gehrels 2
79P du Toit-Hartley
80P Peters-Hartley
81P Wild 2
82P Gehrels 3
83P Russell 1
84P Giclas
85P Boethin
86P Wild 3
87P Bus
88P Howell
89P Russell 2
90P Gehrels 1
91P Russell 3
92P Sanguin
93P Lovas 1
94P Russell 4
96P Machholz 1
97P Metcalf-Brewington
98P Takamizawa
99P Kowal 1
100P Hartley 1
101P Chernykh
102P Shoemaker 1
103P Hartley 2
104P Kowal 2
105P Singer Brewster
106P Schuster
107P Wilson-Harrington
108P Ciffreo
109P Swift-Tuttle
110P Hartley 3
111P Helin-Roman-Crockett
112P Urata-Niijima
113P Spitaler
114P Wiseman-Skiff
115P Maury
116P Wild 4
117P Helin-Roman-Alu 1
118P Shoemaker-Levy 4
119P Parker-Hartley
120P Mueller 1
121P Shoemaker-Holt 2
122P de Vico
123P West-Hartley
124P Mrkos
125P Spacewatch
126P IRAS
127P Holt-Olmstead
128P Shoemaker-Holt 1-A
128P Shoemaker-Holt 1-B
129P Shoemaker-Levy 3
130P McNaught-Hughes
131P Mueller 2
132P Helin-Roman-Alu 2
133P Elst-Pizarro
134P Kowal-V\u00e1vrov\u00e1
135P Shoemaker-Levy 8
136P Mueller 3
137P Shoemaker-Levy 2
138P Shoemaker-Levy 7
139P Vaisala-Oterma
140P Bowell-Skiff
141P Machholz 2
142P Ge-Wang
143P Kowal-Mrkos
144P Kushida
145P Shoemaker-Levy 5
146P Shoemaker-LINEAR
147P Kushida-Muramatsu
148P Anderson-LINEAR
149P Mueller 4
150P LONEOS
151P Helin
152P Helin-Lawrence
154P Brewington
155P Shoemaker 3
156P Russell-LINEAR
157P Tritton
158P Kowal-LINEAR
159P LONEOS
160P LINEAR
161P Hartley-IRAS
162P Siding Spring
163P NEAT
164P Christensen


[Limax7]

I made 3 separate ssc files

- observable_comets_limax7.ssc (71,8 KB - 200 comets)
- periodic_comets_limax7.ssc (212 KB - 509 comets)
- all_comets_limax7.ssc (580 KB - 1445 comets)

-------------------------------------------------------------
observable_comets_limax7.ssc
include comets are now observable from MPEC site
http://www.cfa.harvard.edu/iau/Ephemerides/Comets/
they are comets with any Eccentricity (e>0)


periodic_comets_limax7.ssc
include all periodic comets with P<500 years
from JPL Small-Body Database Search Engine
http://ssd.jpl.nasa.gov/sbdb_query.cgi


all_comets_limax7.ssc
include all 1445 known comets !
I delete SOHO, SOLWIND, SMM, STEREO, SL-9, some 73P comets
WARNING!
This is big database, if you have fast computer try this ssc

SAMPLE:

Code: Select all

"1P Halley" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 75.3144682529955
PericenterDistance 0.58597811151691 
Eccentricity 0.967142908462304 
Inclination 162.262690579161
AscendingNode 58.42008097656843
ArgOfPericenter 111.3324851045177 
Epoch 2446467.395317050925 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"2P Encke" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 3.2991327303073
PericenterDistance 0.33697582465724 
Eccentricity 0.847945637099232 
Inclination 11.782849029898070369881
AscendingNode 334.5696032945518
ArgOfPericenter 186.4988142344296 
Epoch 2455415.077574995194 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"3D Biela" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 6.6453998084776
PericenterDistance 0.87907300000000 
Eccentricity 0.751299000000000 
Inclination 13.2164
AscendingNode 250.669
ArgOfPericenter 221.6588 
Epoch 2390514.115200000000 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"4P Faye" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 7.5449922856010
PericenterDistance 1.66684364415039 
Eccentricity 0.566699693074667 
Inclination 9.0326420735810071249716
AscendingNode 199.2981744211227
ArgOfPericenter 204.9946138410795 
Epoch 2454054.914067051241 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"5D Brorsen" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 5.4610932643418
PericenterDistance 0.58984700000000 
Eccentricity 0.809796000000000 
Inclination 29.3821
AscendingNode 102.9676
ArgOfPericenter 14.9468 
Epoch 2407439.534100000000 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"6P d''Arrest" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 6.5349017473728
PericenterDistance 1.35350166986915 
Eccentricity 0.612772593283101 
Inclination 19.515058152217129361361
AscendingNode 138.9372240555536
ArgOfPericenter 178.1263147955168 
Epoch 2454693.465579595856 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"7P Pons-Winnecke" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 6.3590647273978
PericenterDistance 1.25330362427865 
Eccentricity 0.634858833624845 
Inclination 22.310388068978131315134
AscendingNode 93.4231454334208
ArgOfPericenter 172.3264237702483 
Epoch 2454736.132588034605 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


[Marco Klunder]

4.
In your list above, you name for instance Hale-Bopp, but I cannot find it back in your SSC.

Hale-Bopp is in my comets.ssc

I searched for the name "Hale-Bobb" in your ssc file and did not find it (as in your code list the code and name were mentioned both) and apparently only the code is present in your old ssc file. Indeed it is both present in your new ssc file now (including the name), so this issue is solved

Although the standard comets.ssc contains only 4 comets, they contain very famous ones like Halley, Borrelly and Hale-Bopp, which I cannot find back in your Add-on.

My mistake Halley and Borrelly are and were present indeed.

Your new download is improved indeed, including the issue about the "/" character , although I still think that naming the code of the comet prior to the generic name of the comet (formal notation), result in a more difficult search using the [Enter] <name> [Enter] method, because you exactly need the code first to let the generic name appear in the selection. For those who are not familiar with these codes (as I am one of them ), e.g. looking for comet "Ikeya-Zhang", I first have to find out somewhere else that it has code 153P before I can find and select it in Celestia.
On the other hand, I also understand that many comets have the same generic reference name, like LINEAR, and can just only be selected by their code.
I'm not sure what's best, but you enclosed an index .txt file now, so matching name and code is made a bit easier

In your readme.txt you advise to copy the files to the extras directory.
That's OK with me, but that also leaves the original comets.scc active, resulting in actual duplicate entries for the default comets (although named different).
Advise to enclose a comment in your readme.txt to do something with the original comets.ssc file in the data directory, or to replace the original comets.ssc with one of your files (after making a backup of the original file first of course).

duplicate Halley.jpg

Probably another additional warning for your own files in the readme.txt too, because when you first copy observable_comets_limax7.ssc OR periodic_comets_limax7.ssc and later want to replace them with all_comets_limax7.ssc, it's obvious to delete the first two first, to prevent duplicate entries.
Although you mention the term "separate" in your readme.txt, I think a warning on this point can be very useful too.

Great work, thanks.

Marco

[selden]

In principle, no manual editing of the original SSC file should be needed when changing an object's characteristics, including its visibility. The new SSC file can contain a Modify statement which replaces the original comet definition by the new one.

Renaming an SSC object is a different problem, though.
Celestia really needs to support a Delete prefix.

[Limax7]

I change names to double destignations, but only in all_comets_limax7.ssc (593 KB - 1445 comets)

SAMPLE:

Code: Select all

"1P Halley:Halley" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 75.3144682529955
PericenterDistance 0.58597811151691 
Eccentricity 0.967142908462304 
Inclination 162.262690579161
AscendingNode 58.42008097656843
ArgOfPericenter 111.3324851045177 
Epoch 2446467.395317050925 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"2P Encke:Encke" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 3.2991327303073
PericenterDistance 0.33697582465724 
Eccentricity 0.847945637099232 
Inclination 11.782849029898070369881
AscendingNode 334.5696032945518
ArgOfPericenter 186.4988142344296 
Epoch 2455415.077574995194 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"3D Biela:Biela" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 6.6453998084776
PericenterDistance 0.87907300000000 
Eccentricity 0.751299000000000 
Inclination 13.2164
AscendingNode 250.669
ArgOfPericenter 221.6588 
Epoch 2390514.115200000000 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"4P Faye:Faye" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 7.5449922856010
PericenterDistance 1.66684364415039 
Eccentricity 0.566699693074667 
Inclination 9.0326420735810071249716
AscendingNode 199.2981744211227
ArgOfPericenter 204.9946138410795 
Epoch 2454054.914067051241 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"5D Brorsen:Brorsen" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 5.4610932643418
PericenterDistance 0.58984700000000 
Eccentricity 0.809796000000000 
Inclination 29.3821
AscendingNode 102.9676
ArgOfPericenter 14.9468 
Epoch 2407439.534100000000 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}


"6P d'Arrest:d'Arrest" "Sol" {
  Class "comet"
  Mesh "asteroid.cms"
  Texture "asteroid.jpg"
  Radius 3.1
  EllipticalOrbit
  {
Period 6.5349017473728
PericenterDistance 1.35350166986915 
Eccentricity 0.612772593283101 
Inclination 19.515058152217129361361
AscendingNode 138.9372240555536
ArgOfPericenter 178.1263147955168 
Epoch 2454693.465579595856 
MeanAnomaly 0.0
 } 
RotationPeriod 10 
Albedo 0.04
}

Try it change orginal comets.ssc to comets.xssc so Celestia will don't read this file.

[Cham]

Adam,

thanks for your work.

First, I strongly suggest that you also add a second name to objects in the other files too. Not just for the file "all_comets".

Also, I noticed that there are many objects with the ":" in their name, while there isn't a second name. For example "C-146 P1:" "Sol". See also the code example below. If there isn't a second name, you shouldn't add the ":".

I suggest that you place all the objects with Eccentricity 1.000000010000000 at the end of the file, so the user could edit it easily. Eccentricity >= 1 may give some problems to Celestia.

Finally, please, do some better formatting to the code, like this :

Code: Select all

"C442 V1:" "Sol"
{
   Class "comet"
   Mesh "asteroid.cms"
   Texture "asteroid.jpg"
   Radius 3.1

   EllipticalOrbit {
      Period 1892505499410.980
      PericenterDistance 1.53000000000000
      Eccentricity 1.000000010000000
      Inclination 106
      AscendingNode 271
      ArgOfPericenter 178
      Epoch 1882846.5
      MeanAnomaly 0.0
   }

   RotationPeriod 10
   Albedo 0.04
}


EDIT : I just noticed that the MeanAnomaly is set to 0.0 for ALL your comets !?? I used the NASA database myself, and I'm getting != 0 MeanAnomaly. Also, I don't get exactly the same orbital period as you (in years). So I strongly feel that your files are unreliable.

[Limax7]

Also, I noticed that there are many objects with the ":" in their name, while there isn't a second name. For example "C-146 P1:" "Sol". See also the code example below. If there isn't a second name, you shouldn't add the ":".

ohh, I miss this, I fix this

I suggest that you place all the objects with Eccentricity 1.000000010000000 at the end of the file, so the user could edit it easily. Eccentricity >= 1 may give some problems to Celestia.

That's good idea!

Finally, please, do some better formatting to the code, like this :

Code: Select all

"C442 V1:" "Sol"
{
   Class "comet"
   Mesh "asteroid.cms"
   Texture "asteroid.jpg"
   Radius 3.1

   EllipticalOrbit {
      Period 1892505499410.980
      PericenterDistance 1.53000000000000
      Eccentricity 1.000000010000000
      Inclination 106
      AscendingNode 271
      ArgOfPericenter 178
      Epoch 1882846.5
      MeanAnomaly 0.0
   }

   RotationPeriod 10
   Albedo 0.04
}


hmm, I try do that to

EDIT : I just noticed that the MeanAnomaly is set to 0.0 for ALL your comets !?? I used the NASA database myself, and I'm getting != 0 MeanAnomaly. Also, I don't get exactly the same orbital period as you (in years). So I strongly feel that your files are unreliable.

Yes, MeanAnomaly it's zero because Epoch (JD) is the Time of Pericenter (JD)

With period I have some problems. Celestia read eliptical orbits (e<1) In this case period of body is:
P = (q/(1-e))^1.5

If e>1 (hyperbola) period:
P = (q/(e-1))^1.5

When comet have e=1.0 then I have trouble to calc Period so I change e to 0.999999999
In some cases my Office Calc don't calculate Period so I change e to 1.000000010000000

In JPL/NASA sites Period are very similar to that what I calc.

Please belive my, this comet database is very acurate.

PS. I change to double names to other files to soon.

Adam

[Cham]

Well, just for the fun of it, I'm creating a comets file too from the NASA web site, and I'm getting EXACTLY the same values for Halley's comet as the standard SSC definition included in Celestia.

The values aren't exactly the same as yours...

[Marco Klunder]

First, I strongly suggest that you also add a second name to objects in the other files too. Not just for the file "all_comets".

I agree on that one.

By the way, a good solution to change names to double destignations

Although in my previous posts about this Add-on I had some remaks on the code placed before the generic name of the commet, I did not mean to eliminate it at all. I thought about first mentioning the generic name, followed by the code (so vice versa). The problem you introduce now with this solution without a code in the second destignation, is that all commets with the same generic name like LINEAR, NEAT, (Levy), etc. just now have one entry left that can be selected in the [Enter]<name>[Enter] method instead of all (of course only when someone is used to first mentioning the generic name instead of the code).

In principle, no manual editing of the original SSC file should be needed when changing an object's characteristics, including its visibility. The new SSC file can contain a Modify statement which replaces the original comet definition by the new one.

Renaming an SSC object is a different problem, though.
Celestia really needs to support a Delete prefix.

Good idea

Marco

[Limax7]

OK I add double destignations to all 3 ssc files and fix names with one destignation.

[Cham]

Here's an alternate version. All the known comets with eccentricity < 1 (936 objects) :

Comets_936.ssc.zip

Some informations are given in the SSC file...

The code name is shown first, to reduce screen clutter. Of course, you can still select the comet using its common name, with the <enter><name><enter> method.

The SSC file is also giving the theoretical (calculated) orbital period as an option. By default, the orbital period is the value from the database, when there is one. The user can switch the period value, using a proper search/replace...

[Marco Klunder]

Here's an alternate version. All the known comets with eccentricity < 1 (936 objects) :

Comets.ssc.zip

Some informations are given in the SSC file...

Martin, unfortunately there is no Comets.ssc.zip attached in your post above

Marco

[Cham]

Martin, unfortunately there is no Comets.ssc.zip attached in your post above

Doh ! Do it again. I just updated the file for few corrrections...

[BobHegwood]

Doh ! Do it again. I just updated the file for few corrrections...

Martin,

Just wanted to thank you for creating this file.
Much easier to use for the Brain-Dead.

Thanks very much, Brain-Dead Bob

[cheekygeek]

Greetings earthlings!
I have not learned yet how to create .ssc files and appreciate the packages provided here.

Has anyone included the 103P/Hartley 2 comet with the latest orbital ephemerides in their package?
http://cometography.com/pcomets/103p.html
http://www.aerith.net/comet/catalog/0103P/
http://scully.cfa.harvard.edu/~cgi/ReturnPrepEph?d=c&o=0103P

Thanks for any replies!

Darren Addy
Kearney, Nebraska

[selden]

Darren,

There's a description of how to translate orbital parameters from the format used in IAU circulars to Celestia's SSC format at
http://www.lepp.cornell.edu/~seb/celest ... meris.html

The second and third references you provided above include parameters in IAU format.

[fsgregs]

Martin:

Thanks for the work you and the others have done. I installed your comets_936 file but things sure look weird. Here is a screenshot of a large group of those comets all lined up in a line, with their tails blazing. My FOV is 32 so it is not some strange positional effect. You can check it out by this cel:url:

cel://Follow/Sol:1884%20O1/2010-08-28T04:22:15.30141?x=AMCQArpqtRQD&y=ACD97dlwoPsD&z=AAAGQPMDOXQf&ow=0.98615&ox=0.124171&oy=0.109835&oz=0.00511756&select=Sol:1884%20O1&fov=32&ts=1&ltd=0&p=0&rf=319383&lm=32896&tsrc=0&ver=3, or just select a comet and go to it, then back off a bit.

comets 1.jpg

Obviously, these comets should not all have tails and they are not supposed to be lined up in a nice circle around the sun like this. ????



FYI

Frank