SM targetting

Do SMs target on asteroids or planets if that is what is closest?

I'm working on a perl script to deal with all this for PBeM.  I
have easy turning (You give ships speed, current direction, and
turn and it does the rest), each player gets a file every turn
with his current directions.  I have objects that the game moves
(IE Asteroids), I have auto map sizes.	I have yet to do the parts
that make sure 1) you start in the position you ended AND 2) do
a legal move.  I also have mines in the works (calculate ships
movement, check for distance of mine to ships movement (point 
to line for 1 line, point to lines for 2 point).  I currently
have SM to closest ship with 6MU.  I also have a printout that
is range and arcs to everything other than SMs on the board.
I do not yet verify that SMs are fired at legal ranges from
their ships.  When I do however I'm thinking about having the
SMs go ballistic and not target if fired at too great a range.
(Come on, SQR((ShipX - SalvoX)^2 + (ShipY - Salvo&)^2 )

Other parts I am working on are EW.  What is the recommendation
for ranges?  I'm now thinking ship exists across the map, 80
for a mass (spoofable via EW) 40 for class, 12 for a look at
the SSD.  You'ld get a circle (of appropriate color) beyond
80,  You'ld get a filled circle of appropriate size and color
beyond 40, and ship pictures once the ship entered 40 MU.
Even if range increased you should always get whatever your
best info was.

One potential problem is currently this is all for cinematic.
Eventually I'll move to vector.

Roger