#solar system  for explanation--see python 11
import random
import time
import math
from Tkinter import *
frmMain = Tk()
myCanvas = Canvas(width=400, height=400, background="dark blue")

edegrees = 270
vdegrees = 270
mdegrees = 270
myCanvas.create_oval(180,180,220,220,fill="orange")
#the sun--this doesn't move

for i in range(200):
    ex = 200 + int(150 * math.cos(edegrees * math.pi/180))
    ey = 200 + int(150 * math.sin(edegrees * math.pi/180))
    vx = 200 + int(100 * math.cos(vdegrees * math.pi/180))
    vy = 200 + int(100 * math.sin(vdegrees * math.pi/180))
    mx = 200 + int(75 * math.cos(mdegrees * math.pi/180))
    my = 200 + int(75 * math.sin(mdegrees * math.pi/180))
    myCanvas.create_oval(ex,ey,ex+10,ey+10,fill="green",outline="green")
    myCanvas.create_oval(vx,vy,vx+7,vy+7,fill="yellow",outline="yellow")   
    myCanvas.create_oval(mx,my,mx+4,my+4,fill="red",outline="red")
    myCanvas.pack()
    myCanvas.update()
    time.sleep(0.1)
    myCanvas.create_oval(ex,ey,ex+10,ey+10,fill="dark blue",\
                         outline="dark blue")
    myCanvas.create_oval(vx,vy,vx+7,vy+7,fill="dark blue",\
                         outline="dark blue")
    myCanvas.create_oval(mx,my,mx+4,my+4,fill="dark blue",\
                         outline="dark blue")
                         
    mdegrees = mdegrees + 10
    vdegrees = vdegrees + 5
    edegrees = edegrees + 2


myCanvas.pack()
frmMain.mainloop()