GlowScript 2.9 VPython

get_library('https://cdn.rawgit.com/PERLMSU/physutil/master/js/physutil.js')

#Objects
Voyager = sphere(pos=vector(-5e10,-2e10,-3e9), radius=3e9, color=color.green, make_trail=True)
Asteroid = sphere(pos = Voyager.pos + vector(-3e10,8e10,3e9), radius=5e9, color=color.red, make_trail=True)
 

#Parameters and Initial Conditions
vVoyager = vector(1e5, 1e4, 1e4)
vAsteroid = vVoyager + vector(1e5,-9e4,0)

#Time and time step
dt = .25e6
t = 0
tf = 1e6

#MotionMap/Graph
trackVoyager = MotionMap(Voyager, tf, 5, markerScale=1e5)
trackAsteroid = MotionMap(Asteroid, tf, 5, markerSacale=1e5)
separation = PhysGraph(numPlots=1)
 
#Calculation Loop
while t < tf:
    rate(10)
    
    Voyager.pos = Voyager.pos + vVoyager*dt
    Asteroid.pos = Asteroid.pos + vAsteroid*dt
    
    trackVoyager.update(t,vVoyager)
    trackAsteroid.update(t,vAsteroid)
    separation.plot(t,mag(Voyager.pos-Asteroid.pos))
    
    t = t + dt