$fn=128;

rotate([180,0,0]) {
    difference() {
        union() {
            scale([1,1,0.6]) {
                sphere(d=22);
            }
            cylinder(h=20,d1=22,d2=16);
            }
        scale([1,1,0.5]) {
            sphere(d=12.5);
        }
        cylinder(h=20,d=12.5);
    }
}