Roy Smith wrote:
In article ,
Stubby wrote:

Roy Smith wrote:
Mxsmanic wrote:
From what I've read, the ANS looked specifically at stars, not
planets, but I may be wrong.
Planet, star, it's all the same. It's a point of light in the sky. The
ephemeris calculations are a little more complicated for a planet, but
that's only something you'd notice if you were working it out with pencil
and paper.
But aren't the stars stuck to the celestial sphere so that their motion
is fairly simple and easy to predict. Planets are zipping around the
sun, as is the Earth, and the Earth is turning on its own axis. Much
more complicated.

Depends on your definition of "Much more complicated".

If you're doing it the traditional way, working from the Air (or Nautical)
Almanac with paper and pencil, reducing a planet sight is a couple more
table lookups and a couple more additions or subtractions. Some hulking
mainframe did all the really messy math for you a year or two earlier, in
plenty of time for the tables to be typeset, printed, and bound.

If you're doing it all from scratch with a computer, all the formulas you
need can be found in Jean Meeus's "Astronomical Formulae For Calculators"
(http://www.willbell.com/math/mc3.htm). The book was published in 1979,
and gave formulas usable on the popular hand calculators of the day to
achieve accuracies exceeding any practical navigational need.

I would worry about running out of fuel while I'm trying to figure that
book out and fat-fingering the calculator.