from visual import *

def get_v(radius,period):
    return vector(0,2*pi*radius/period,0)

jupiter = sphere(pos=(5.200,0,0),color=color.green,radius=0.06,make_trail=True)
mercury = sphere(pos=(0.388,0,0),color=color.blue,radius=0.06,make_trail=True)
venus   = sphere(pos=(0.723,0,0),color=color.yellow,radius=0.06,make_trail=True)
earth   = sphere(pos=(1.000,0,0),material=materials.earth,radius=0.06,make_trail=True)
mars    = sphere(pos=(1.523,0,0),color=color.red,radius=0.06,make_trail=True)
sun     = sphere(pos=(0,0,0),color=color.orange,material=materials.emissive,radius=0.2,make_trail=True)

jupiter.velo=get_v(5.200,11.86)
mercury.velo=get_v(0.388,0.24)
venus.velo=get_v(0.723,0.62)
earth.velo=get_v(1,1)
mars.velo=get_v(1.523,1.88)
dt=0.002

while True:
    rate(200)
    for p in [mercury,venus,earth,mars,jupiter]:
        r=sqrt((p.x)**2+(p.y)**2)
        p.velo = p.velo-vector(4*(pi**2)*p.x*dt/(r**3),4*(pi**2)*p.y*dt/(r**3),0)
        p.pos  = p.pos+(p.velo[0]*dt,p.velo[1]*dt,0)