Celestia Forums

My first Luatools add-on: the sun and SS planets Roche's limit (for testing). Surely, an add-on of this kind could be numerically hardcoded in the Luatools for all bodies, but in meantime...



The limits are purely theoretics (2.456 x radius) as given here:

http://media4.obspm.fr/exoplanets/pages_outil-roche/calcul-limiteRoche.html

so if one know which actually they are, please, let share this information and I shall update the add-on.

http://fenerit.webng.com/files/luatools_roche_limit.zip

In the zip there is an image file with the instructions explaning where two code's lines may be add to the extant config.lua and toolBox.lua files. This add-on has been tested with 4479 patch (globular clusters) but it is suited also for all that versions which allow the setvisible function to work properly.

Massimo,

This is great. And it's really good to know that new tools can be easily added to the
standard toolbox. I'd like to keep the standard toolbox as succint as possible, though.
So we could start to think about a way of gathering the extra tools (forum thread,
internet page...). Maybe the simplest way, at least for the moment, would be to use
the 'Lua Edu Tools - How to add your own feature' thread.

Previous link has been updated with the data computed accordingly with this calculator

http://www.merlyn.demon.co.uk/gravity5.htm#Roche

I've add also the Moon. Repeat the same operation (cut and paste RocheLimitBox.lua in \tools folder) except the two lines of code.

Vincent wrote:Massimo,

This is great. And it's really good to know that new tools can be easily added to the
standard toolbox. I'd like to keep the standard toolbox as succint as possible, though.
So we could start to think about a way of gathering the extra tools (forum thread,
internet page...). Maybe the simplest way, at least for the moment, would be to use
the 'Lua Edu Tools - How to add your own feature' thread.

Merci, Vincent. Indeed. Probably there is need of a structure like the organizer chart (cascade menu)? In this manner perhaps the five navigation "voices" could result compacted as "sub charts" of a one?

Something like this, just to explain a little clean:

I don't know much about that, only what I read on this page :http://en.wikipedia.org/wiki/Hill_sphere but i think
It would be also interesting that with Roche's limit, you draw Hill 's limit, wouldn't be?

Fenerit the Roche Limit is a little bit more complicated then what you posted. The density of the object comes into play that determines where an object will start to rip apart.
Below is the full formula, Because Saturn only has a density of .62 g/cm? it effect the range of the Roche Limit at any give distance. I broke it down into 1 (g/cm?) increments. If you wanted to see how close the earth could get to Saturn before being ripped apart, take the formula and substitute (d) with 5.5153 (g/cm?) and you get a distance of 70,477,049m

L=2.423*R*((D/d)^(1/3))

Roche Limit (L) 124,519,516 (m)
Radius of Primary (R) 60,268,000 (m)
Density of Primary (D) 0.62 (g/cm?)

Density of Child (d) # (g/cm?)
Roche Limit (9g/cm?) 59,862,739
Roche Limit (8g/cm?) 62,259,758
Roche Limit (7g/cm?) 65,093,568
Roche Limit (6g/cm?) 68,525,730
Roche Limit (5g/cm?) 72,819,455
Roche Limit (4g/cm?) 78,442,380
Roche Limit (3g/cm?) 86,337,010
Roche Limit (2g/cm?) 98,831,205
Roche Limit (1g/cm?) 124,519,516

MKruer, surely the Roche limit it's more complicated, because depend on the density of the secondary body. I've just assumed that the orbiting body have the same density of the main object, otherwise would have been too complex depict all the continuous density values, since also centesimals alters the limit. Your examples would be interesting, if possible of course, for a LuaTools' Roche calculator, in which putting the data and a function which would draw the result. But it's just a suggest for the future.