Not quite celestial mechanics, but fun to play with.
set display mode 800,600,32
color backdrop 0,rgb(0,0,0)
backdrop on 0
autocam off
sync on
set camera range 0,0.1,3000
hide mouse
phy start
phy set gravity 0.0,0.0,0.0
x#=20.0
for t=1 to 5
make object sphere t,4,32,32
color object t,rgb(0,200,0)
set object specular t, rgb ( 0,200,0 )
set object specular power t, 255
set object ambient t, 0
position object t,x#+t*10,0.0,0.0
phy make rigid body dynamic sphere t
phy set rigid body linear velocity t,0,0,10.0
next
Sun=10
make object sphere Sun,8,32,32
position object Sun,0,0,0
color object Sun,rgb(0,0,0)
set object emissive Sun,rgb(255,255,0)
phy make rigid body dynamic sphere Sun
phy set rigid body kinematic Sun,1
phy create force field 1
phy set force field coordinates 1,1
phy set force field constant 1,-2000.0,4000.0,0.0
phy set force field rigid body 1,Sun
phy build force field 1
phy add force field sphere 1,0,0.0,0.0,0.0,128.0
position camera 0,0,100,-100.0
point camera 0,0,0,0
do
phy update
sync
loop
Ad Astra Per Asper