Review of Astronomy Programs (SynTax disk 402)

                     by Ian Taylor

This disk contains four programs for the PC which deal with
various aspects of astronomy.  Two of the programs are very
professional in appearance while the other two were written in
Basic and look like it.

                     Solarpix
                     --------

This is a program that aims to show the orbits of the various
bodies in our solar system and to give a few facts about them as
well.  It's written in Basic and as a consequence the display is,
to put it mildly, crude.  Each of the bodies is represented
graphically by a full stop.  Admittedly the "point" representing
the sun is slightly bigger than the ones representing the planets,
but you get the idea: pretty graphics are not this program's
strong point.  I'd be hard-pushed to say what is, except that the
source listing is supplied, so you could always soup it up to your
own requirements (however see CGSS below).  When you run Solarpix,
you are presented with a menu of four choices: Sun and planets,
Sun, Earth and Moon, Comets, or Facts.  Sun and planets gives you
the orbits and relative velocities of up to five planets, shown by
five dots moving round a larger central dot, faster or slower,
depending on your key presses.  You enter a start date and time
and the program calculates the positions at that time and
continues from there.  Sun, Earth and Moon is similar, except for
the obvious difference.  Comets asks you for the eccentricity of
orbit and then shows a dot moving around a central dot at a quite
furious pace which you can't alter.  Facts gives a few basic facts
about the various bodies in the solar system.  All in all, not
recommended.

                         Stars
                         -----

Another Basic program, this is a simulation of the night sky.
Again you enter date and time as well as latitude and the program
displays what the night (or day) sky looks like.  Night has a
black background, day has a blue one.  The program is fast but the
only problem is that the graphics are so awful that I couldn't
identify a single constellation apart from "The Big Dipper" (well
approved astronomical name!) in the quiz that comes with it.  Your
chances of identifying virtually anything else are microscopic.
Compared to Skyglobe this really is awful.  However, it is PD and
it does have the source with it.

                         Skyglobe
                         --------

An impressive program this.  The graphics may only be EGA, but to
be honest they're more than adequate to portray the night sky.
This is another simulation of the night sky, complete with
constellations, stars, the ecliptic etc.  The program allows you
to vary just about everything from the magnitude of the stars
which are displayed to the constellation lines (display all, some
or none) and whether or not to display the ecliptic, star labels,
whether or not to move the display round automatically.  Skyglobe
has some pretty good documentation and an unsubtle plea for
registration - we're in the realms of shareware here.  I think
this program would be more than adequate for the casual observer
and is well worth the $10/$15 registration fee.  Highly
recommended.

                         CGSS
                         ----

This is basically a collection of annotated diagrams of the
various members of the solar system.  However behind that dry
statement of fact lies a package which would be of enormous
benefit to anyone interested in learning more about the solar
system and its members.  I don't consider myself an astronomy
ignoramus by any means, but there's a lot of information I didn't
know in this package.  The program has a menu with sub-menus for
Sun, Earth, Moon, Planets and General. To give you an idea of the
scope of this package, under the Sun sub-menu there are options
for Structure, Size and Mass, Nuclear Cycle, Solar Phenomenon,
Life Cycle and Data.  Each of these has several pictures with lots
of info and occasionally a short animation such as an illustration
of the causes of the various types of eclipse.  Comets, asteroids,
tides and even gravity and time are all covered in this extremely
impressive package, which I'm surprised is not at least shareware
if not actually a commercial package!  I have only two caveats
(for there is no documentation):  there is no mouse control (a bit
irritating at times, but livable with).  Secondly, on a 486, the
animations run so quickly that you hardly have time to blink (at
last a use for that Turbo button!).  If you have kids doing
astronomy for the National Curriculum get this - it'll save hours
of encyclopaedia hunting.