<sect1 id="tool-solarsys">
<title>Solar System Viewer</title>
<indexterm><primary>Tools</primary>
<secondary>Solar System Viewer</secondary>
</indexterm>

<screenshot>
<screeninfo>
The Solar System Viewer
</screeninfo>
<mediaobject>
  <imageobject>
    <imagedata fileref="solarsystem.png" format="PNG"/>
  </imageobject>
  <textobject>
    <phrase>Solar System Viewer</phrase>
  </textobject>
</mediaobject>
</screenshot>

<para>
This tool displays a model of our solar system as seen from
above, for the current date and time in the main window.
The Sun is drawn as a yellow dot in the center of the plot,
and the orbits of the planets are drawn as circles with correct
relative diameters, centered on the Sun.  The current position
of each planet along its orbit is drawn as a colored dot along
with a name label.  The display can be zoomed in and out with
the <keycap>+</keycap> and <keycap>-</keycap> keys.
</para>
<note>
<para>
The current version of this tool shows a very simplified model
of the solar system; we are planning on several improvements in
future versions.  For example, the orbits will be displayed as
ellipses, not perfect circles.  We will also make it possible to
recenter the display at any location (currently, the center is
fixed at the Sun), and allow the date to be changed, including
the ability to animate the display with a variable timestep.
Finally, we would like to add comets and asteroids as well.
</para>
</note>
</sect1>
