From: sterner@warper.jhuapl.edu (Ray Sterner)
Subject: PC Starchart/Planetarium program review.
Organization: Johns Hopkins University
Date: 10 Nov 92 21:19:50 GMT

  Starchart/Planetarium program for IBM PCs and compatibles
  ---------------------------------------------------------

  I was digging around on the network a while back and came across
  an excellent starchart program for IBM PCs/compatibles.  The
  program has too many features to give a full list here but I will
  describe some of them below.

  The program is shareware and is one of the truely great bargins at
  $20.  It runs very well on my 386/25 monochrome LCD notebook computer,
  but I didn't know about the colorful graphics until I ran it on our
  486/33 at work.  The program is very well written and a user's manual
  is included in the *.zip file.

  The program is not available on non-IBM compatible computers, such as
  Macintosh.  The documentation states that a lot of the code is in
  assembler, great for speed, but not for portability.

  This program would make a good Holiday or birthday present for anyone
  interested in astronomy that has the right computer.
  
  How to get the program
  ----------------------
 
  I found the program on an anonymous ftp site.  The commands are:

  ftp wuarchive.wustl.edu   (Washington University, St. Louis, MO)
    (I don't have a list of other archive sites that have this program.)
  For name enter:     anonymous
  For password enter: your email address
  Change directories: cd mirrors/msdos/astronomy
  Set to binary mode: binary
  Download:           get skygl352.zip  (that's SKYGL, not G1, but lowercase).
    (check the name, the version number changes with updates.
     To get a directory listing do: ls)
  Exit ftp:           bye

  Unzip the zip file on your PC.  The program runs under MSDOS and Windows 3.X.
  The user's manual has Windows setup instructions.

  If you can't download the software from a BB or archive site you can
  call the company direct (KlassM SoftWare) and order it.
  The number is: 1-800-968-4994, its the best software buy at $20 I've
  seen so far.

  Educational site licenses are also available.

  A description of the program
  ----------------------------

  The program has a very large number of options.  One nice feature that
  makes this number manageable is that option control keys often cycle
  through a number of closely related options or levels.

  Here is a list of some of what the program displays:

  Objects
  -------
  Stars: number selectable from 300 to 25000.  White and gray.
  Sun/Moon/Planets: the Sun, Moon, and all 9 planets may be displayed
    with or without names.  They may also be turned turned off completely.
    Appropriate colors, Jupiter has a red spot, the Moon shows quarters.
  Milky Way: may be displayed in 2 shades of gray or blue or just as
    contours of 2 levels.  If gray or blue is used both the fainter and
    brighter parts of the milky way may have their intensity adjusted.
  Deep sky objects: all Messier objects may be shown, plus some NGC objects.
    All may be turned off.  Objects may be turned on at one of 5 levels
    of completeness.  White.
  Coordinates
  -----------
  Horizon: The horizon display may be cycled through the following:
    off, Horizon only (with direction labels), +zenith, + 15 deg altitude tics.
    Horizon in green, zenith and tics yellow.
  Ecliptic: on or off. Orange.
  RA and Dec lines: off, 3 hrs/45 deg, 1 hr/15 deg.  Gray.
  Labels
  ------
  Stars: off, brightness sequence number, names, names (bold).
    The number of stars labeled may also be controlled.  Orange.
  Constellations names: off, 3 letters, small text, large text. White.
  Lines
  -----
  Outline: off, screen, round map area.  White.
  Constellations: constellation lines may be cycled through several
    levels, from asterisms to major constellations to all constellations.
    One key toggles the current setting completely on or off.  Orange, red.
  Constellation boundaries: on or off.  Orange.

  Here is a list of some of what the program does:

  Date and Time: may be incremented or decremented by 1 minute, 1 hour,
    1 day, 1 month (30 days), 1 year, 1 century, 1 millenium.  Its not hard
    to select a certain date and time.
  Zoom: May zoom in or out.  At full zoom the Keystone of Hercules fills
    the screen.  With all 25000 stars turned on I counted 18 inside the
    Keystone.  At minimum zoom the entire sky is a small circle on the
    screen.
  Pan: May pan around the sky using the arrow keys.  The mouse makes it
    even easier, just click on a point to center on the display.
  Location: may select from a large number of locations around the world.
    May also move in steps from selected location.
  Find: may find and center on the display the Sun, Moon, any planet,
    many stars, constellations, deep sky objects.
  Twilight mode: brightens the sky background while the sun or moon is
    above the horizon.  The background darkens as the sun drops lower in
    the sky and below the horizon.  The moon has a similar but smaller
    effect.
  Turbo mode: repeat a command until stopped.  This is really the highlight
    of the program and will be described next.

  Animation:
  
  SkyGlobe even without animation would be a bargain, but it is designed
  to show the motions in the sky and does this very well.  One very nice
  feature is the real time mode which shows the sky as it currently is,
  updating the display once each minute.  I've watched the sun cross the
  sky on a rainy day while I worked on another computer.

  The really fun animation is done using the turbo mode which repeats any
  command.  Using turbo mode to increment time by 1 day follows the sun
  on its path along the ecliptic as the background stars slide behind it
  in their westward drift.  The orbits of Mercury and Venus around the
  sun become quite a bit more obvious.  If the time increment is set to 1
  sidereal day the stars appear frozen while the Sun, Moon, and Planets
  move across the sky.

  A new feature in the latest versions (3.52 has it) is the ability to
  track any object.  I was going to suggest this addition but it appeared
  before I could, the author seems to know just what to add to make the
  program an excellent teaching tool.  I tried tracking on Mercury
  after zooming out to show the sky as a globe and minimizing the
  number of stars to get the fastest speed.  The program preserves up and
  down at the center of the display, that is, the display is in
  altazimuth coordinates.  This gives some really wild animation when
  tracking on Mercury.

  I also used turbo mode to watch the sun trace out an analemma in the
  morning sky.  Combined with a VGA projection system such a demonstration
  would be a good way to explain to an astronomy class such things as why
  the year's latest sunrise doesn't happen at winter solstice and other
  related topics.

  I found an interesting grouping of Solar System objects using turbo
  mode.  Seven objects come together in a group less than 10 degrees
  across.  This happens on 12 Jan, 1994 (at about 0:00 UT to include
  the moon about the best).  Use the program to view it from the South
  Pole.  The objects are: Moon, Mercury, Venus, Mars, Uranus, Neptune,
  and, unfortunately, the Sun (which makes it all invisible).

  Turbo mode may be used with other commands, such as Pan or Zoom (gives
  a Startrek Warp-like effect).  The number of stars displayed may also
  be animated using turbo mode.  Precession is nicely shown by incrementing
  by centuries or millenia.

  Conclusion

  This is shareware at its best.  The author of this software is well
  worth supporting, especially if it allows him to produce other such
  excellent programs.  I would recommend this program to any amateur
  astronomer with an IBM PC or compatible computer.  Also to any science
  class that deals with astronomy, from grade school up to college.

  Ray Sterner                     sterner%str.decnet@warper.jhuapl.edu 
  Johns Hopkins University        North latitude 39.16 degrees.
  Applied Physics Laboratory      West longitude 76.90 degrees.
  Laurel, MD 20723-6099