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XBrain130
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Great Comet Collection

26 Feb 2017 06:37

Decided I wanna try to publish something, so I decided to start with something light.

scr00040.png


As the title says, it's pretty much a collection of 42 great comets (comets big and bright enough to be visible to the unaided eye near perihelion) appeared in the last 2000 years, from Ceasar's comet of 44 BC to 1996's Hyakutake.

Some notes:
  • Since almost all of these comets passed before the advent of hi-tech telescopes, I assumed a diameter of 20 km for every one, with the following exceptions: Hyakutake (known to be 4.2 km across), fragments (which are sized as 20 km divided by the number of fragments of that comet), and the 1811 one (which was estimated to be around 35 km according to Wikipedia)
  • I set the "Epoch" to the perihelion passage date and "MeanAnomaly" to 0, so to find the perihelion passage date, simply bring up the comet's in-game wiki page and look at "Pericenter Epoch" in the "Orbit" page
  • Since luminosity also depends on random outbursts of activity, some of these comets are invisible from Earth even during perihelion. Usually they are a few magnitudes under 7 so increasing the minimum magnitude should reveal them.
  • Missing from this compilation are Halley, Hale-Bopp, McNaught, and Lovejoy; they're already present in SE's default catalogue.
  • For some reason comet tails don't seem to be rendered inside a sunlit atmosphere, so if you want to observe these comets as they appeared from Earth, I suggest to either look from orbit or disable atmospheres (as with the screenshot).

Just drop this file in the "\addons\catalogs\planets" folder and you should be ready to go comet-hunting in the past :)

Changelog:
  1. February 26: First release, then removed non-alphanumerical characters from "de Cheseaux" (GC of 1744)
  2. February 27: Added GC of 1887, GC of 1865, "Messier" (GC of 1769), and "Sarabat" (GC of 1729); renamed GC of 1881 to "Tebbutt" and GC of 1823 to "de Breaute-Pons"
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Last edited by XBrain130 on 27 Feb 2017 04:56, edited 3 times in total.
 
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SpaceEngineer
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Great Comet Collection

26 Feb 2017 11:39

Great addon XBrain130.

There is a small mistake. Avoid to use non-alphanumerical characters in a catalog file (i.e. use only English letters). In my system with Russian as a default language language, I see this:

► Show Spoiler


SE displays correctly name of this comet in English localization and other localizations which uses win-1252 font. But in other localization it doesn't. To make a localized name of an object, use the SE wiki.
 
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XBrain130
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Great Comet Collection

26 Feb 2017 12:16

Thank you for the compliment and the heads up. I'll fix it immediately and keep it in mind if I do other public addons in the future.
 
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XBrain130
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Great Comet Collection

27 Feb 2017 04:58

Added four more and named two after a quick search through Wikipedia, more specific in the opening post.
 
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Xoran
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Great Comet Collection

27 Feb 2017 09:46

XBrain130, great addon :)
SpaceEngineer, could this addon become a part of SpaceEngine 0.9.8.1?

However, can masses of comets be randomly generated, so that many of them do not have exactly the same size, but similar masses instead? ;)
Space is too big to understand, so do not try to understand.
 
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XBrain130
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Great Comet Collection

27 Feb 2017 11:22

Xoran wrote:
Source of the post XBrain130, great addon :)

Thank you!
Xoran wrote:
Source of the post However, can masses of comets be randomly generated, so that many of them do not have exactly the same size, but similar masses instead? ;)

The problem is that even if I specify "Asteroid-class comet", without size and mass they become Gas giant-class planets in the game, for some reason.

And mass is even more random than size, given that the former is a function of not only the latter, but also of density, which can be anywhere from water-like (dirty snowballs) to silicate-like (icy dirtballs). So I just gave them a large-ish size.

But it could be nice if Asteroid-class objects (proper asteroids, comets, minor moons) were given a appropriate procedural mass and size without having to input either one.
 
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SpaceEngineer
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Great Comet Collection

27 Feb 2017 13:38

XBrain130 wrote:
Source of the post The problem is that even if I specify "Asteroid-class comet", without size and mass they become Gas giant-class planets in the game, for some reason.

Hmmm, this is probably a bug. Normally SE generates a density in a range 0.5-1 for comets, then calculates mass/size. So specifying only mass or only radius must work.
 
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XBrain130
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Great Comet Collection

27 Feb 2017 13:52

SpaceEngineer wrote:
XBrain130 wrote:
Source of the post The problem is that even if I specify "Asteroid-class comet", without size and mass they become Gas giant-class planets in the game, for some reason.

Hmmm, this is probably a bug. Normally SE generates a density in a range 0.5-1 for comets, then calculates mass/size. So specifying only mass or only radius must work.

Yeah, specifying mass and/or radius does work. But by specifying neither, they somehow becomes a gas giant regadless of the assigned class.

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