Xplanet Frequently Asked Questions

None of my scripts work with the new version.
Why is there a configuration file now? I want to specify everything on the command line.
How do you show multiple bodies? I want to see the moon when I draw the earth.
I used the -starmap option but I don't see any stars.
I don't see Saturn's rings.
How can I get xplanet to work with KDE?
How can I get xplanet to work with Gnome2?
Where can I get higher resolution cloud maps?
Why are the top and bottom of the cloud maps a reflection of the area below/above them?
How can I get Xplanet to draw an image once and exit?
The -animate option doesn't work any more. Will it be back in a future version?

None of my scripts work with the new version.

The 1.0 version of Xplanet is a complete rewrite of the pre-1.0 version. Many of the old options work differently, or not at all. I really should have named the 1.0 version "Xplanet2" to make this clear, since a lot of people were inconvenienced by upgrading. I apologize for this. The old version is still available here, although I will only make bug fixes on this version from now on.

Why is there a configuration file now? I want to specify everything on the command line.

Xplanet now draws multiple bodies. By using a configuration file, you can specify things like marker or arc files for each planet. Doing that on the command line would be a pain.

How do you show multiple bodies? I want to see the moon when I draw the earth.

Xplanet draws multiple bodies by default. Multiple bodies are not drawn if the -projection option is used. If you only see one body in the image, then it means there aren't any other bodies (that xplanet knows about) in the field of view.

The moon orbits at 60 earth radii. You won't often see it in the field of view if the earth is drawn at any appreciable size.

You can modify the magnify parameter in the configuration file to make the earth and moon bigger so that they do fall in the same field of view more often. It won't be accurate, but it might be what you want. See this image in the gallery for an example.

I used the -starmap option but I don't see any stars.

You probably have a small field of view, and there just aren't any stars that fall inside your image. By default, xplanet places the observer at 1000 planetary radii.

Try this:

  xplanet -num_times 1 -label -radius 10 -range 1000

Notice the "fov" line in the label. Decrease the range, and the field of view will get larger and you will start to see stars and other planets in the image. You won't see much until the fov gets to be a few tens of degrees.

Another thing you can do is set the "magnify" option inside the configuration file. See the "multiple bodies" question above - it's really the same question as this one. You might want to use a magnify value of 100 or more to see a lot of stars.

I don't see Saturn's rings.

Saturn's rings are in the plane of its equator. If the observer is at latitude 0, you won't see anything.

Try this:

  xplanet -body saturn -latitude 25

The rings are not drawn if the -projection option is used. Rings for the other planets are not implemented.

How can I get xplanet to work with KDE?

From Jeremy Sonander <Jeremy at saros dot com>:
     - Right click on the backdrop, and select "Configure desktop"
     - Select Background
     - Go to the Wallpaper tab and select no wallpaper
     - Go to the Background tab and select Background Program from the Mode tab
     - Click Setup
     - There should already be an Xplanet entry. Select this and click Modify
     - The Command and Preview Command should be
         xplanet --num_times 1 --geometry %xx%y --latitude 20 --output %f.png && mv %f.png %f

How can I get xplanet to work with Gnome2?

Modify the following script to suit your preferences:



#!/bin/bash

# Add this script to System->Preferences->Sessions->Startup Programs

# how long to sleep between drawings
sleep=2m

# screen size
geometry=1680x1050

# where to keep the desktop image
prefix=${HOME}/.gnome2_private/
logFile=${prefix}/xplanet.log

# the name of the desktop image
base=xplanet
extension=png

# check to see if we're still logged in
loggedIn=$(ps U $USER | grep gnome-session|grep -v grep)
if [ -z "$loggedIn" ]; then
    echo "exiting at $(date)" >> $logFile
    exit
fi

# Alternate between two filenames
append=2
first=${base}.${extension}
second=${base}${append}.${extension}

currentBackground=$(basename $(gconftool -g /desktop/gnome/background/picture_filename))

# Set the name of the output file to be different than the current background
  if [ $currentBackground != $first ]; then
  outputFile=${prefix}/${first}
 else
   outputFile=${prefix}/${second}
fi

# Remove the current background once the new background has been set
rmFile=${prefix}/${currentBackground}

# The xplanet command
xplanet -num_times 1 -output $outputFile -geometry $geometry	\
        -body major -random -range 20 -label -labelpos -10+30 >> $logFile

# update Gnome backgound
gconftool -t str -s /desktop/gnome/background/picture_filename $outputFile

# Now get rid of the previous background
if [ -e $rmFile ]; then 
    sleep 1
    /bin/rm $rmFile
fi

sleep ${sleep}

# Run this script again
exec $0

Now from the GNOME desktop menubar, select System -> Preferences -> Sessions and choose the Startup Programs tab. Browse to where you saved the above script and select it. Click Add. Remove this entry if you don't want XPlanet backgrounds any more.

Where can I get higher resolution cloud maps?

I don't know of any other real time global cloud map sources. The ones I create are based on infrared images from geostationary satellites. The resolution of my maps are constrained by the resolution of the original images, so I can't make bigger ones. If you want higher resolution maps, try launching your own network of weather satellites!