Projects - Canvas scenes - Solar system

So

//------------------
// PARAMETRES LUNE
//------------------
var rapDisSolLune = 10, disLune = sole.W/2,
rapSolLune = 9;

tPla["lune"] = {
   NOM:    "Lune",
   DIST:   disLune,
   X:      tPla["terr"].X,
   Y:      tPla["terr"].Y-disLune,
   RAD:    0,
   W:      sole.W/rapDisSolLune,
   COL:    "#e4e4e4",
   COLIGHT : hextoCanCol("#e4e4e4", opaTraj),
   VIS:    false,
   RAPSOL: rapSolLune,
   RAPDISOL:0.7,
   VITESSE: 0.11,
   DECALFROMRAD : 3.9
}

Tips:
To make a dust effect on canvas content do not use the default clearcanvas method but use a 'fillrect'
For example, you can say in jquery that if your dust option is checked your alpha indice is lower than 1.
With this alpha the fillRect will not cover all the canvas and on each animationframe it will be more dark. This is how you can do a dust effect:

function clearCanvas(){
  var indice = (opt_trne) ? 0.4 : 1;
  ctx.fillStyle   = "rgba(29,29,29,"+ indice +")";
  ctx.fillRect(0, 0, oCanvas.W, oCanvas.H);
}