From: Orcinus orca [email removed]
John H. Kim says:
>If you're only interested in an occasional eclipse or two,
>it's a great idea. The impression I got from the original
>letter (I don't save these for much more than a day so I
>can't check) was that he wanted to know what the night sky
>would look like given a certain time and place. If you use
>T. L. Hayes's simplification for this, you get the boring
>(in my opinion) result of all the planets/moons/suns lined
>up in one line in the sky. I like to imagine the view at
>Regina as something like the Saturn mosaic JPL released,
>with a moon here and there. I suppose you could fake it.
On the contrary, Kepler's law does not restrict you from having the planets/
moons inclined to the plane of the orbit of the primary body. I suggested
it as a simple way to tell where along an orbit the object would lie without
going through detailed astro-mechanical calculations. A little trig and
knowledge of the inclination would easily allow you to determine the angle
above or below the ecliptic (reference the main planet). All this assumes
you really want this much detail but you don't want to spend a lot of time
doing detailed calculations. To generate a "sky view" simply determine
where all the objects (visible ones) are along their orbits then assuming
you know or have set the angle of inclination and the nodes you can easily
determine the apparent asimuth and elevation of the object of interest.
What you do need to do is make a lot of simplifying assumptions like all the
orbits are circles (so you can tell from the period where along the orbit
the planet is) and none of the orbits (nodes) precess otherwise you may as
well go back to the full calculations using orbital elements.
From: [email removed] (C. Harald Koch)
>> I personally would not like to have my main asteroid defense be how thick
>> my hull was, because there's eventually a bigger asteroid out there with
>> your name on it!
>
>I agree, you still need an active defense system of some sort. However, no
>matter how sophisticated your sensors are, there will be space dust smaller
>than they can detect. There is also a size below which there is no point
>trying to destroy incoming objects because they are too hard to hit.
Perhaps we should install (or assume these are already installed?) a
navigational deflector (like the Enterprise has) based on repulsor technology.
All it does is project a beam of repulsive force (how does it do this I
wonder) in the direction of motion and "sweep" back and forth clearing a
path through the MICRO-meteroids/asteroids. It would have little effect on
anything of any real size (to prevent if from being used as an extra weapon)
but then things that big are a) rare and b) easy (relatively) to avoid.
TLH
- - --
T.L.Hayes |
MIT/Lincoln Laboratory |
Lexington, MA |