submission by SSample
function setup(){
  var myCanvas = createCanvas(800, 800); //you must keep this line unmodified

}

function draw() {
  //start writing your code here
  var black = color(0, 0, 0)
  var white = color (255, 255, 255)
  var star_size = 3
  var green = color(128, 255, 128)
  var blue = color(0, 0, 255)
  var earth_size = 50
  var moon_color = color(127, 138, 128)
  
  background(black)
  fill(white)
  noStroke()

  for(y = 10; y<= 800; y+= 35) {
    for(x = 10; x <= 800; x += 20) {
      ellipse(x, y, star_size, star_size)
      ellipse(y, x, star_size, star_size)
    }
  }
  fill(blue)
  ellipse(350, 400, earth_size, earth_size)
  fill(moon_color)
  ellipse(400, 390, earth_size/4, earth_size/4)
  fill(green)
  ellipse(350, 400, earth_size / 3, earth_size * 0.7)
  ellipse(355, 392, 26, 20)   // earth and moon
}