private void DrawUfo(Ufo ufo, Graphics g)
{
var centerToDraw = ufo.GetCenterToDraw();
var headToDraw = ufo.GetHeadToDraw();
g.DrawEllipse(Pens.DarkSeaGreen, headToDraw.X, headToDraw.Y,
ufo.Body.Ry * 2, ufo.Body.Ry * 2);
g.DrawEllipse(Pens.DeepSkyBlue, centerToDraw.X, centerToDraw.Y,
ufo.Body.Rx * 2, ufo.Body.Ry * 2);
}