Re: Orbits Defined

Indy wrote:

[examples of low orbit from a scale based on a 12" diameter planet]

Would this give geostationary orbit at about radius 30" ?
(or 18" above the surface)

>  (another example, if anyone remembers the
> fireball/meteoroid that skipped off of Earth's atmosphere back on
August
10,
> 1972, the one that was filmed passing over the Rockies in broad
daylight,
it
> would have been, using the scale above, a mere 1/16th inch above the
surface
> of the globe)

Hey! some of us were only 4 then.  :-)

[ NO, I'm not remotely interested in finding out how old everyone else
is,
and
I doubt anyone else is either after the "where does everyone live?"
thread.
]

> >>  Geosynchronous orbit is where the unit (ship, station, etc.) is
> >> traveling at such a speed in orbit that it remains above the same
spot
on
> >> the globe.

> There is also a minimum distance above the surface of the body to
consider.

Err, the only minimum distance I can think of is the distance at which
you've
entered the atmosphere (or for airless bodies: hit the surface).

> Geostationary orbits do require a particular distance. At least a
minimum
> distance. For Earth this minimum distance is 35,000 km.

Its a particular distance, not a minimum one. If you go further out
you're
not
geostationary either - ie you take more than a day to complete each
orbit.

[ The obvoius example of this is the moon, much  further out than
geostationary
orbit, taking 28 days to complete an orbit. ]

If you use the semi-offical scale of 1 turn = 20 mins then the Earth
would
take
72 turns to rotate once. A ship in geostationary orbit would take the
same
time to complete one orbit (I think this is speed 2.5MU/turn). This
might
be
a little slow to game with. Still, you can allways tweak the scale to
suit
your tastes.

Alun.
(alun.thomas@cbis.com)