ANDREA wrote:(but why there are so many lines with "#BLANK"?)
Each line in the SSC format corresponds to particular asteroids and moons from the Calculation sheet. Not all asteroids have moons. Where there is no moon #BLANK lines will be exported instead of orbital elements. The same applies to asteroids that are culled due to being in a Kirkwood gap.
The #BLANK lines are very easy to remove if you have access to a Linux system. This code:
Code: Select all
grep -v "#BLANK" < raw-file-with-blanks > asteroids.sscshould do the job nicely. This is trickier to do with Windows, but I use Textpad and do a regular expression search-and-replace to remove these lines.
ANDREA wrote:Perhaps it can work arounf a star, but not around a planet?
Can give some explanation on how to use it, please?
Thanks a lot.
Bye
Andrea
I have never tried it around a planet instead of a star. I don't guarantee that the spreadsheet will perform reliably in such a situation.
At present, the spreadsheet works best for asteroid belts bounded by a small inner planet (like Mars) and a large outer planet (like Jupiter). In the future I would like to add support for asteroid belts with a small outer planet and a large inner planet, and also Kuiper belt support. I haven't yet done the research into the orbital resonances for these classes of asteroid belt so I cannot yet add these modes.
As for documentation, I'm working on supplying some, but at present my focus has been to get the spreadsheet working right.
selden wrote:Bruce,
For a future version of Asteroid Maker, you might want to consider varying the color and albedo values for the different types of asteroids (C, S and M).
The default color values are not correct and I hope to correct this soon. I'll have a look at the original asteroids' SSC file and use the color values from that in the next version.
Almost all the constants on the Constant sheet of the spreadsheet are editable (perhaps this page should have been called Variables). If users wish to change the values then they are free to do so.
selden wrote:Bruce,
Another suggestion:
Include a 4th sheet that's an SSC defining the two planets.
At present, the addon is intended to be used to create an asteroid belt for a predefined planetary system.
This is a good idea and I may do it, but not in version 1.4.
At present, the planets' parameters on the main page lack some information needed for complete orbital definitions. If a complete SSC file is required, a lot of extra data must be supplied. How much more information is needed? Do we want just enough to have a complete set of orbital parameters, or will other settings like textures, atmosphere and rings be needed? I would prefer to output just the orbital parameters, and let users supply the rest by editing the SSC file after the spreadsheet is done with it.
ANDREA wrote:I tried to go to #153, and I had a flight INTO Pluto, then THROUGH an asteroid, reaching at the end a crouch of asteroids, one into the other or mixed together, as you see here (remember, we are IN an asteroid which is IN Pluto)
I believe your problem may be happening because of the different units that Celestia uses for orbits. Orbits of planets around stars are expressed in Astronomical Units (AU), but orbits of moons around planets are expressed in kilometres. The spreadsheet is designed for asteroids around stars, so it uses AU for all orbits.
I have not tried it, but I believe that if you are using the default settings for asteroids around planets, then the asteroids will appear inside Pluto in the manner you described.
The orbital periods will also be incorrect. The spreadsheet uses solar masses as the mass unit for calculating the orbital periods.
The spreadsheet can be used to generate asteroids around planets, but the user will need to do the research and some experimentation to discover the correct values to use. Users will need to change the units from AU and solar masses to kilometres and some suitable value that gives correct orbital periods.
