GlowScript 2.8 VPython
# Circular Planetary Motion
obj=sphere(pos=vector(10,0,0),radius=0.5,color=color.red)
sun=sphere(pos=vector(0,0,0),radius=1.0,color=color.yellow)


# Setting initial conditions and step size, dt
t=0 
dt=1
y0=2
v0=0.0
theta=0
thetavenus=0
omega=2*pi/365


# This is main part - the loop
while True:
    rate(100)
    x=10*cos(theta)
    y=10*sin(theta)
    obj.pos=vector(x,y,0)
    theta=omega*t
    t=t+dt