createCanvas(400, 400, WEBGL);

  perspective(PI / 3.0, width / height, 0.1, 500);

  print("earth (flat) in center\nsun orbit 1d\nmoon orbit 28.2d\nuse: mouse drag xy, mouseWheel zoom??");

}

​

function draw() {

  background(0, 0, 80);

  orbitControl(0.5, 0.5);

  earth();

  sun_move();

  moon_move();

}

​

function earth() {

  push();

  fill(0, 100, 150);

  stroke(0, 0, 200);

  strokeWeight(0.1);

  //noStroke();

  cylinder(30, 5);

  pop();

}

​

let sr = 150;

let sang = 0,

  dsang = 0.01745;

​

function sun_move() {

  push();

  let x = sr * sin(sang);

  let z = sr * cos(sang);

  let y = 0;

  translate(x, y, z);

  sang += dsang;

  fill(200, 200, 0);

  noStroke();

  sphere(10);

  stroke(200);

  pop();

  push();   // add path

  noFill();

  stroke(200,200,0);

  strokeWeight(0.8);

  rotateX(-PI/2);

  circle(0,0,sr);

  pop();

}

​

let mr = 100, mra=0.9,mrb=1.1;

let mang = 1.57, dmang = 0.01745;

​

function moon_move() {

  push();

  let x = mra * mr * sin(mang);

  let z = mrb * mr * cos(mang);

  let y = 0;

  translate(x, y, z);

  mang += dmang / 28.2;

  fill(120,120, 100);

  noStroke();

  sphere(25);

  pop();

  //no path

}