-background background_file
Use background_file as the background image, with the planet to be
superimposed upon it.  This option is only meaningful with the
azimuthal, mollweide, orthographic, and peters projections.

-body body
Render an image of the specified planet or satellite.  Valid values
for body are sun, mercury, venus, earth, moon, mars, phobos, deimos,
jupiter, io, europa, ganymede, callisto, saturn, mimas, enceladus,
tethys, dione, rhea, titan, hyperion, iapetus, phoebe, uranus,
miranda, ariel, umbriel, titania, oberon, neptune, triton, nereid,
pluto, charon, random, and major.  Earth is the default body.  This
option is the same as -target.

-center +x+y
Place the center of the rendered body at pixel coordinates (x, y).
The upper left corner of the screen is at (0,0). Either x or y may be
negative.  The default value is the center of the screen.

-color color
Set the color for the label.  The default is "red".  Any color in the
rgb.txt file may be used.  Colors may also be specified by RGB hex
values; for example -color 0xff and -color blue mean the same thing,
as do -color 0xff0000 and -color red.

-config config_file
Use the configuration file config_file.  The format of config_file is
described in README.config.  See the description of -searchdir to see
where xplanet looks in order to find the configuration file.

-date YYYYMMDD.HHMMSS
Use the date specified instead of the current local time.  The date is
assumed to be GMT.

-date_format string
Specify the format for the date/time label.  This format string is
passed to strftime(3).  The default is "%c %Z", which shows the date,
time, and time zone in the locale's appropriate date and time
representation.

-font fontname 
Set the font for the label.  Only TrueType fonts are supported.

-fontsize size 
Specify the point size.  The default is 12.

-fov
Specify the field of view, in degrees.  This option and the -radius
option are mutually exclusive.  This option has no effect if the
-projection option is used.

-geometry string
Specify the window geometry using the standard X window geometry
syntax, [<width>{xX}<height>][{+-}<xoffset>{+-}<yoffset>]
(e.g. 256x256-10+10 puts a window 256x256 pixels in size 10 pixels
away from the right side and 10 pixels below the top of the root
window).  This option implies -window, but can also be used with
-output.

-gmtlabel
Same as the -label option, but show GMT instead of local time.

-hibernate seconds
After the screen has been idle for the specified number of seconds,
xplanet will sleep.  This option requires xplanet to have been
compiled with the X Screensaver extension.

-idlewait seconds
Don't run Xplanet unless the screen has been idle for the specified
number of seconds.  This option requires xplanet to have been compiled
with the X Screensaver extension.

-jdate Julian date
Use the specified Julian date instead of the current local time.

-label
Display a label in the upper right corner.

-labelpos
Specify the location of the label using the standard X window geometry
syntax.  The default position is "-15+15", or 15 pixels to the left
and below the top right corner of the display.  This option implies
-label. 

-latitude latitude
Render the target body as seen from above the specified latitude (in
degrees).  The default value is 0.  

-light_time
Account for the time it takes for light to travel from the target body
to the observer.  The default is to ignore the effects of light time.

-longitude longitude 
Place the observer above the specified longitude (in degrees).
Longitude is positive going east, negative going west (for the earth
and moon), so for example Los Angeles is at -118 or 242.  The default
value is 0.

-make_cloud_maps
If there is an entry in the config file for cloud_map, xplanet will
output a day and night image with clouds overlaid and then exit.  The
images will be created in the directory specified by -tmpdir, or in
the current directory if -tmpdir is not used.  The names of the output
images default to day_clouds.jpg and night_clouds.jpg, but may be
changed by the -output option.  If "-output filename.extension" is
specified, the output images will be named "day_filename.extension"
and "night_filename.extension".  The dimensions of the output images
are the same as the day image.

-markerbounds filename
Write coordinates of the bounding box for each marker to filename.
This might be useful if you're using xplanet to make imagemaps for web
pages.  Each line looks like:

204,312 277,324 Los Angeles

where the coordinates are for the upper left and lower right corners
of the box.  This file gets rewritten every time xplanet renders its
image.

-north north_type
This option rotates the image so that the top corresponds to north in
the given coordinate system: "body", "galactic", "orbit", or
"terrestrial".  The default value is "body".

-num_times num_times
Run num_times before exiting.  The default is to run indefinitely.

-origin body
Place the observer at the center of the specified body.  Valid values
are the same as for -target.  In addition "above" or "below" may be
specified, in which case the view is centered on the body's primary
and the field of view is large enough to show the body's orbit.  If
the body name is preceded by a dash, the observer is placed on the
opposite side of the target from the specified body at a distance
equal to the distance between the target and body.  For example,
-target earth -origin sun places the observer at the center of the
sun.  If -target earth -origin -sun is used, the observer is placed on
a line connecting the centers of the earth and sun at a distance of 1
AU farther from the sun than the earth.  

-origin_file origin_file
Specify a list of observer positions in origin_file.  Each line should
be of the form
YYYYMMDD.HHMMSS range lat lon
For example,
19951207.120000  10.328  -3.018  97.709
Range is in planetary radii, and lat and lon are in degrees.  For each
line in the origin file, the observer is placed at the specified
position, relative to the body specified with -origin.  This option is
useful for showing spacecraft flybys or orbiting around a planet.

-output filename
Output to a file instead of rendering to a window.  The file format is
taken from the extension. Currently .gif, .jpg, .ppm, .png, and .tiff
images can be created, if xplanet has been compiled with the
appropriate libraries.  The image size defaults to 512 by 512 pixels
but this may be changed by the -geometry flag.

-post_command command
-prev_command command
Run command either before or after each time xplanet renders an image.
On MS Windows, you may need to use unix-style paths.  For example:
xplanet.exe -prev_command ./prev.bat

-print_ephemeris
Print the heliocentric rectangular equatorial coordinates (J2000) for
each body xplanet knows about, and then exit.

-projection projection_type
The projection type may be one of ancient, azimuthal, hemisphere,
mercator, mollweide, peters, orthographic, or rectangular.  The
default is no projection.  Multiple bodies will not be shown if this
options is specified, although shadows will still be drawn.

-quality quality
This option is only used when creating JPEG images.  The quality can
range from 0 to 100.  The default value is 80.

-radius radius 
Specify the radius of the globe as a percent of the screen height.
The default value is 45% of the screen height.  When drawing Saturn,
the radius value applies to the radius of the outer ring.

-random
Place the observer above a random latitude and longitude.

-range range
Render the globe as seen from a distance of range from the planet's
center, in units of the planetary radius.  The default value is 1000.
Note that if you use very close ranges the field of view of the screen
can be greater than 180 degrees!  If you want an "up close" image use
the -radius option.

-rotate angle 
Rotate the globe by angle degrees counterclockwise so that north (as
defined by the -north argument) isn't at the top.  The default value
is 0.  My friends in the Southern Hemisphere can use -rotate 180 to
make the earth look like it should!  For non-orthographic projections,
the globe is rotated and then projected, if that helps you visualize
what to expect.

-searchdir directory
Any files used by xplanet should be placed in one of the following
directories depending on its type: "arcs", "config", "fonts",
"images", "markers", "origin", "satellites", or "stars".  By default,
xplanet will look for a file in the following order:
The current directory
searchdir
subdirectories of searchdir
subdirectories of xplanet (if it exists in the current directory)
subdirectories of ${HOME}/.xplanet on X11
subdirectories of ${HOME}/Library/Xplanet on Mac OS X
subdirectories of DATADIR/xplanet
DATADIR is set at compile time and defaults to /usr/local/share.

-starfreq frequency
Fraction of background pixels that will be colored white.  The default
value is 0.001.  This option is only meaningful with the azimuthal,
mollweide, orthographic, and peters projections.

-starmap starmap
Use starmap to draw the background stars.  This file should be a text
file where each line has the following format:
magnitude  RA	dec
where RA is in decimal hours and dec is in decimal degrees.  For
example, the entry for Sirius is
-1.46       6.75247222     -16.71611111
See the description of -searchdir to see where xplanet looks in order
to find the star map.

-target target
Same as -body.

-tt
Use terrestrial time instead of universal time.  The two differ
slightly due to the non-uniform rotation of the earth.  The default is
to use universal time.

-timewarp
As in xearth, scale the apparent rate at which time progresses by
factor.  The default is 1.

-tmpdir tmpdir
Specify a directory that xplanet will use to place images created
using -make_cloud_maps.  Also on Microsoft Windows, xplanet will write
a bitmap file called xplanet.bmp to the specified directory.  The
default is the result of the GetWindowsDirectory call (C:\WINDOWS on
Win95).

-transparency
Update the background pixmap for transparent Eterms and aterms.  This
option only works under X11.

-transpng filename
Same as the -output option, except set the background to be
transparent when writing a PNG file.  

-verbosity level
level	   output
< 0	   only fatal error messages
0	   non-fatal warning messages
1	   basic information         
2	   basic diagnostics         
3	   more detailed diagnostics 
4	   very detailed diagnostics 
The default value is 0.

-version
Display current version information.

-vroot
Render the image to the virtual root window.  Some window managers use
one big window that sits over the real root window as their background
window.  Xscreensaver uses a virtual root window to cover the screen
as well.

-wait wait
Update every wait seconds.

-window
Render the image to its own X window.  The size defaults to 512 by 512
pixels but this may be set by the -geometry flag.

-window_title title
Set the window's title to title.  This option implies -window.

-xscreensaver
Same as -vroot.
