Set the date to July 1, 2006. Turn off the horizon and
daylight displays. Using the “Settings” button, set the
orientation to Equatorial. Open the Planet Palette and
center the display on Mars. Be sure to notice the relationship
between Mars and Sun. Center the display on
the Sun and lock on the Sun. Find Mars again and click
on it to display its name. Set the step size to 3 days and
start the clock. Stop the clock when Mars passes the Sun
and step back and forth until Mars and the Sun are in
conjunction. Using the Selection Tool, point the arrow at
Mars and record the date and the distance of Mars. Repeat
for the next three conjunctions of Mars. Using your
data, estimate the synodic period of Mars. How can you
account for the different distances of Mars at the time of
conjunction in terms of the shapes of the orbits of Mars
and the Earth?
