Heavens Above



Author: Jay Davis

Date: September, 1993

Keywords: astronomy program review utility application

Text:
In this age of electric lighting, stars and the heavens seem less
urgent than they once were.  Perhaps that's why the common
constellations have such antiquated names as Ursa Major (Big Dipper) or
Cassiopeia; the Queen of Cepheus. Still, consid-ering that it was
allegedly a giant comet that ended the reign of dinosaurs, perhaps we
should not completely ignore the skies.
My astronomy knowledge is remarkably meagre.  On a good night I can
identify the Moon and the Big Dipper.  With coaching I can find the
Little Dipper. I mention this because a person who is more familiar
with astronomy might have had a different--and presumably easier--
experience with MacStronomy.
MacStronomy 2.0 comes on 2 disks and the Mag 8 Database on an
additional two. The entire folder takes up 3.1 megs on my hard disk,
considerably less if you don't buy the Mag 8 database. The manual is
100 pages, and begins with a series of 8 exercises to demonstrate the
workings of the program. I went through the exercises, learning to use
the various controls.  With simple mouse clicks you can change your
gaze from north to south or any place on a 360* compass.  You can also
look straight up or straight down, and anything in between. You can
have the horizon appear as a line, or for greater realism a shaded area
through which you can still see the stars that would be visible if
there were no horizon in the way. Dates, times, and locations are also
adjustable. A long list of cities is available (including Eureka,
California!) as well as all the planets of the solar system. Thus you
can view the sky from almost anywhere in the universe. By the way, if
your city does not appear in the listing, you can add it, if you know
its longitude and latitude.
I walked through the tutorials, adjusting this control and that,
exactly as advised in the manual. The steps were quite simple to
perform, but I felt like a monkey being led through a car tune-up: I
never really got an idea of what I was doing by setting all these
little controls. After  my first few weeks with the program, I was
terribly disappointed. NO, I hadn't read the Reference section of the
manual: reference sections shouldn't be necessary for a well-produced
Mac program. 
I was unsure what to do about writing a review. Was my trouble based on
my ignorance of astronomy? Why, for instance, when I opened the program
to the view of Eureka's night sky did I see such a jumble of stars
instead of the few constellations I see from my house in town? In
desperation, I did as they advise in the Mac  Bible. When all else
fails, RTFM (read the manual.)
I redid some of the exercises and studied the reference section of the
manual. I found one important answer there, embedded in the Display
Menu section. A control called ''Magnitude'' determines how bright a
heavenly object has to be for it to be shown on screen. Once I set that
properly, the jumble disappeared, and lo! I could see my old friend the
Dipper and the Moon again. This was getting interesting. 
By now it was night time, and the sky was clear. I set the program to
the current date, current time, Eureka California, and told it to look
west and 45* upward. The screen showed the Moon, the Dipper, and a
number of other stars and constellations. I stepped outside to see if
the screen bore any semblance to the sky I was seeing.  Gads! It did.
My friends the Moon,  and Dipper, were exactly where MacStronomy said
they would be.  
But wait, what was that bright star right next to the Moon? I went back
to the Mac, and selected the ''?'' tool. I clicked it over the bright
thing and in 5 seconds I was advised it was Jupiter, and was given more
information about the planet than I than I cared to know: its distance
from the Sun, its rising, transit, and setting times, and 14 other
facts about the planet--more interesting to an astronomer than a
stargazer like me. Still I was impressed. 
Having identified it, I could have chosen to label it (the label tool),
but I chose not. Next, I decided to see how my night sky would change
over time. Using the time-lapse menu, I could choose any time interval
from one minute to a 1000 years (perhaps longer). By choosing a 15
minute interval, I  could watch the Moon and the constellations move
through my view of Eureka's western sky. I discovered that by fifteen
minutes past midnight, the Moon would sink below the horizon. By  5:30
am Saturn would be where the Moon had started, and The Dipper would be
out of sight. I did not stay up all night to check on MacStronomy, but
judging from its initial accuracy, I'd wager it was correct. 
Then, just for fun, I set the time-lapse interval for 1000 years and
repeated the exercise. Every five seconds a new sky was drawn as it
would appear a millenium later. It may interest you to know that if you
gaze into the southern sky at 10:33 PM on August 10, 7993 you will see
Saturn and the Moon in  conjunction. 
Would I recomend MacStronomy? Yes. Is it a program you just pop out of
the shrink warp and use? For me, the answer is no. But with practice,
it is clearly worth the effort.  
You can do fun things like print up star maps. How about one showing
the night sky on the day a friend was born? Sounds like an appealing
present to me. Or you can let MacStronomy show you a Solar Eclipse
(Exercise 7), or watch the planets orbit around the Sun (Exercise 8).
For astronomy students, MacStronomy may hold much more potential, but
for astro-dummies like myself, it's still worth the price--if you're
willing to put in some effort. Perhaps that's the bottom line: what you
get out of MacStronomy depends on what you're willing to put in. The
price is $60 (add $25 for Mag 8 database).
MacStronomy Version 2.0 is available from: 
Etlon Software
1936 Quail Circle
Louisville, Colorado  80027

Copyright © september, 1993 by Jay Davis