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discovered after you receive Guide (usually, a few are found each
year),  and you may want to display them in Guide.

   If you have access to the Internet,  the easiest way to get
up-to-date orbital elements for comets is to download them from
the Minor Planet Center WWW site,  then use the ""Add MPC
comets/asteroids" described on page 51 to bring them into Guide's
database. This method guarantees good,  current data,  and removes
the need to understand orbital elements.

   You can add asteroids in the same manner,  but this is usually not
a good idea.  The improvement for most asteroids will be essentially
zero,  except in the case of newly-found objects and those for which
the MPC has received enough new data to really revise the orbit.  In
that case,  rather than use the "Add MPC Comets/Asteroids" function,
it is almost always a better idea to switch to use of the MPCORB
database.  This is described on page 51.

   If you lack Internet access,  or if you want to add elements not
available through the MPC (say,  from an article or elements for a
theoretical object),  then you will have to enter the elements by
hand,  using the "Edit Comet Data" function.  Here's how to do this.

   First,  some background on how an orbit is defined: Usually, five
or six figures,  called orbital elements,  are needed. When you "click
for more info" on a comet or asteroid in Guide,  these elements are
among the information listed.

   Orbital elements can be expressed in a variety of ways. Usually,  a
comet's elements consist of a time of perihelion (the time it comes
closest to the Sun),  represented by a capital letter T;  the distance
from the comet to the Sun at the time of perihelion,  or "q";  the
orbit's eccentricity (a measure of how "stretched out" the orbit is; a
value of 1 or greater means the comet won't return),  or "e";  the
longitude of the ascending node,  represented by an uppercase Omega
(looks like a horseshoe);  the inclination,  or "i";  and the argument
of perihelion,  represented by a lowercase omega (looks like a curly
w). These last three are angles that define how the orbit is oriented
in space.

   Asteroid elements usually replace the time of perihelion with an
epoch time and a "mean anomaly",  an angle defining the object's
position along the orbit at the epoch time.  Also, the semimajor axis
("a") is sometimes used in place of the perihelion distance.

   The "Edit Comet Data" function in the Extras menu will provide a
list of recent comets,  plus "(new comet)" and "(new asteroid)"
entries.  You can select an existing object to alter it (useful for
element updates), or either class of new object.

   Next,  you'll get a menu allowing you to adjust and save all the

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