Version 4.0 Jan. 3, 1988

This Program computes information relating to the position, distance,
magnitude, orbit view, skyview, etc for the major planets, four minor
planets or halley's comet on a specified date and time. Also, orbital data
for any desired planet or comet can be entered and saved in a disk file.
Skyview and orbital views can show forward or backward motion. The moons
for each planet can be displayed.

The following programs files are available (the source code can be
obtained from the author if it is not included).

PLANETS.EXE 90K bytes Execution Code
PLANETSA.EXE 100K bytes Execution Code for use with 8087
PLANETS.DOC 20K bytes This File
PLANETS.PAS 57K bytes Source Code for Turbo 4.0
PLANETS1.PAS 42K bytes Include file for Turbo 4.0
PLANETS.3TP 56K bytes Source Code for Turbo 3.0
PLANETS.3TP 42K bytes Include file for Turbo 3.0
PLANETS.SAV 1K bytes Save file made with setup command

Refer to PRACTICAL ASTRONOMY WITH YOUR CALCULATOR by
Peter Duffett-Smith for the calculation methods.

Command List

1 - 9 Entering a single digit will display detailed information
relating to the selected planets. Use the "T" command
to set the time and date, and the "L" command to set the
longitude and latitude. Also the "S" command may be used to
select the format for representing angles.

A- Entering A followed by a single digit will display detailed
information related the selected minor planet or comet. The
last selection in this column is user selectable, via the "R"
and the "W" commands.

B- Entering B followed by a single digit will display the sky
view of the nine major planets and the selected minor planet.
Use the T and the L commands to select the time/date and
longitude/latitude.

C- Entering C followed by a single digit will display the orbits
for the four inner planets and the selected minor planet. The
planets are each shown in its own orbital plane. The distance
between the earth and a comet with a large inclination will
be misleading in the orbital view. However, The distance
calculation using the "A" command does take into account the large
inclination of comets (update from previous versions).

D- Entering D followed by a single digit will display the orbits
for the five inner planets and the selected minor planet. The
planets are each shown in its own orbital plane.

E- Entering E followed by a single digit will display the orbits
for the earth and the five outer planets plus the selected
minor planet. The planets are each shown in its own orbital plane.

F SideView shows the orbit of the selected planet. The scale is
the same as the last scale selected using the C, D or E command.

H Displays this file.


I Plots the orbits and locations of the four inner planets:
Mercury, Venus, Earth, and Mars. The "S" command may be used
to enable/disable the planet names. If the names are shown,
sometimes a name will overwrite a previously displayed planet.

K1,2,3 Gives Keplers three laws along with an example. Note
that Keplers laws refer to the Sun and Planets, but
the law applys to any small body orbiting a large body.

L Allows entry of the longitude and latitude. The longitude is
then used to compute the time zone; which can be changed if
desired.

M Displays the Menu. A second depression switches to the second
page of the menu.

O Plots the orbits and locations of the five outer planets and the
Earth. The "S" command may be used to enable/disable the planet
names and to correct for the aspect ratio of the monitor.


Q Goes Back to DOS


S The Set-Up is command is used to select the form of numeric
printout for angles: hour/deg/min, decimal deg, decimal hours
etc. The screen aspect ratio may be set so that circles come
out correctly on the screen. Also, planet name may be
enable/disabled from orbital and sky plots. One the setting are
entered they can be save in file planets.sav. This file will
be read and the setting updated the next time planets is initialized.

R The read command reads a file made by the (W)rite command and
loads the orbital data into the last minor planet position.
The A through E commands may then be used to make calculations
for the new planet selected.

T The change time/date command allows entry of the time and the
date. Note that spaces (not commas) should be used between the
entries.

V The View command shows how the planets would appear in the
sky on the date selected by the T command and from the location
selected by the L command. If the planet names are shown,
sometimes a name will overwrite a previously displayed planet.

U The U commands shows the sun and the moon as they would appear
on the date selected by the T command and on from the location
selected by the L command.

W The write command is used to enter orbital data for a planet
or comet that is not included in the main program. The data
is then stored in a disk file and read into the last position
in the minor planet column. If the epoch is entered as "0 0 0"
the orbit is assumed to be entered in standard form for a comet;
therefore no prompt is made for the longitude at epoch.

X Two objects are selected from a list of moons and planets for
size comparison. A graphical view is then so that the sizes
can be easily compared.

Y This command shows the sun and the moon against the a grid
showing declination and ascension.

Z This command shows the planets against the stars. A grid
with declination and ascension is shown. The + and - commands
can be used in star view mode.

+ The Plus command is used after a view or orbit command to advance
planets forward in time. Successive depression causes faster motion
in the following order: one hour, one day, one week, one month,
and one year.

- The Plus command is used after a view or orbit command to advance
planets backward in time. Successive depression causes faster motion
in the following order: one hour, one day, one week, one month,
and one year.

space The space key is used to stop advance or backward time travel.
The planets will continue to blink until any other key (except
=,-, or space) is depressed. An M command will then go back to
the main menu.


F1 - F9 Function keys show the selected planet and its inner moons. IF
there are outer moons, they are selected by a shifted function
key. The earth date and time do not apply to moon positions. A
seperate earth day count is shown so that the speed of the moons
can be compared to an earth day.

Glossary of Terms


Azimuth : The angle from the North measured East to West. When
applied to set and rise times for a planet this
indicated where on the horizon, 180 deg. for South,
270 deg. for West, etc.

Daylight Savings : If Daylight savings time is enabled then the local time
is advanced one hour on the last Sunday in March and
set back on the last Sunday in October.

Ecliptic Coordinates : Are related to the earths orbit, Long is the
angle around from the first point of Aries
and Lat is angle Up or Down

Equatorial Coord. : Are related to the earths equator, DEC is how
far north or south of the equator and RA is
angle around the equator from the first point
of Aries

First Point of Aries : This direction remains fixed with respect to the
stars (except for Precession) and is used as a
reference for ecliptic and equatorial coordinates.

GMT : Greenwich Mean Time, time at longitude 0 deg.

GST : Greenwich mean sideral time, is related to the
position of of the stars rather than the Sun.

JD : Julian Day Number is the number of days since
January 1st 4713 B.C.

HA : Hour Angle is the time since the planet crossed
the meridian

helio ecliptic lat. : Angle north or south of the earths orbit

heliocentric long : Angle from the first point of Aries that planet
makes round the sun

Horizontal Coord. : Are related to the observers horizon, Alt is
angle above the horizon and Azim is angle from
the north going east.

Lat : Latitude of observing site

LCT : Local Civil Time (time locally used)

LST : Local Sideral Time, is related to the
position of of the stars rather than the Sun.

Long : Longitude of observing site

long of ascend node : The point where a planet rises out of the plane of
the ecliptic

Mag : Magnitude on a logrithmic scale which measures the
brightness of the planet ( the calculation here is
accurate to only 1 or 2

mean anomaly : Angle a fictitious planet, moving in a circle,
would make with a line from the sun to the
planets perihelion


Phase : Area of the disc which is illuminated

true anomaly : Corrects the mean anomaly to account for 9the
eccentricity of the orbit


radius vector : Distance from the Sun to the planet


Extended Notes:

**** How orbits are shown ****

The orbits for the planets and moon are each shown in its own
orbital plan. This means that the view is not the same as would be
seen from space. Projection of the orbits would have slowed the
motion commands considerably.

**** Entering planet date ****

The (W)rite command makes a file containing the orbital data for
additional planets (one file per planet). A good source for data is
the Astronomical Alamanac is for sale by The Superintendent of
Documents, U.S. Government Printing Office, Wahington, D.C. 20402.

When using data from the Alamanac the Period is calculated:

Per = (360 / 365.2422) / Daily Motion

The Longitude at Epoch is calculated:

Long at Epoch = Long of Asc Node + Long of Per(bar) +
Mean Anomaly

The Longitude of Perihelion is calculated:

Long of Per = Long of Asc Node + Long of Per(bar)

**** Sun and Moon rise and set times ****

The calculation assume a fixed location for the sun and the moon
based on the date and time setting. More accurate times can be
obtained by setting the time to the first value given, then doing
a second iteration.

**** Moon orbital view ****

The orbital views of the moons do not correspond to the date. An
earth day counter is shown to give an idea of the speed of motion.



This program is placed in the public domain and may be freely
copied and distributed for a nominal distribution charge. The Turbo
Pascal source code and the latest version of the program can be
obtained from the author for $10.00.

The following is a list of other scientific programs available form
the author:


CHEMICAL (Current Version 2.2)

CHEMICAL is a molecular modeling Program to aid in the formation
of three dimensional pictures of chemicals. Atoms are selected
from a Periodic Table (using the A command) and electron
orbital information retrieved. The Atoms are then bonded
(using the B command). The chemical is displayed as it is
being constructed. The chemical can be viewed from different
directions by using the up and down cursor keys and the V
command. If desired the Hybrid and Ionize commands can be used
to alter the orbitals before bonding. Atoms can be bonded
into groups, then the groups bonded to other groups to make
large chemicals.

1) CHEMICAL.EXE 260 Kbytes Executable Code
2) CHEM.DOC 12 Kbytes Document file
3) CHEM.TUT 4 Kbytes Chemical Bonding Tutorial
4) CHEM.PRO 22 Kbytes Main Program / Executive
5) CHEMPRED.PRO 3 Kbytes Global Predicates
6) CHEMDOM.PRO 1 Kbytes Global Domains and DataBase
7) CHEMSUB.PRO 21 Kbytes Command Subroutines
8) CHEMRULE.PRO 18 Kbytes Ionize, Hybrid, Bonding rules
9) CHEMDATA.PRO 14 Kbytes Chemical Data Atoms,Radius, etc
10) *.DAT Chemical Data Files made
11) CHEMC.C Source code for C subroutines


CHEMVIEW (Current Version 1.5)

CHEMVIEW is a companion program that shows 3-dimensional
animation of the models generated with CHEMICAL. CHEMVIEW
requires an EGA board and monitor. CHEMVIEW is written in
Turbo PROLOG with the graphics I/O done in Turbo C.
To use CHEMVIEW simply start the program and select the file
desired.

1) CHEMVIEW.EXE Animation program (Pascal)
2) CHEMVIEW.PRO PROLOG Source
3) CALLC.C C Subroutines


CRYSTAL (Will not be completed until late 1988)

CRYSTAL is a companion program that shows 3-dimensional
development of crystals. Atoms and multi-atom ions are
and placed on a lattice to form 3 dimensional models.


These programs are are placed in the Public Domain and may be freely
copied. However, the source code is only available from the author.
The latest version, with source code is available according to the
following proce schedule:
First Copy Updates

Planets $10 (1 disk) $5

CHEMICAL
CHEMVIEW $20 (3 disks) $10
CRYSTAL


Comments, corrections, and suggestions can be sent to the author.

Larry Puhl
6 Plum Ct.
Sleepy Hollow, Ill. 60118