I'll give you a little hint: First, just create one object, give it variable centerx = 300, centery = 300, radiusx = 100, radiusy = 30, angle = 0
every tick for the object, do this:
set angle = object.angle + 360*dt
set x = object.centerx + object.radiusx*cos(object.angle)
set y = object.centery + object.radiusy*sin(object.angle)
Now, run it and you should see the object spinning around in oval manner centered at 300,300. Now, imagine for loop for many objects... does that ring any bell?