Avid cyclists passing
Mercury just southwest of Monona Terrace.
Cyclists passing the earth,
just north of the Brittingham boathouse on Monona Bay.
What is it? Planet Trek Dane County (PTDC) was constructed in April 2009 as a celebration of
Year of Astronomy by UW Space
Place and partners. PTDC is an installation
uniting science education, art, and outdoor
recreation. PTDC is, at heart, a scale model of our
solar system: We shrunk the Sun, planets, and
other bodies by the same factor so that the sizes
and distances are represented to scale relative to each
other. In our model, the scale is about 200 million to
1. This means the Sun is a sphere about 24 feet
in diameter at Monona Terrace, and Pluto the
size of a marble in Mt. Horeb.
NEW IN 2010: An interactive sun dial on the grass next to the Sun.
NEW IN 2012: A remodeled and more attractive version of the sun dial.
NEW in 2014/2015: Planet Trek will remain in place during the winter months.
Where is it? The PTDC Sun is located at Monona Terrace Convention Center in downtown
Madison. Your trek through the solar system follows the
Southwest Commuter Bike Trail, then the Military Ridge
Bike Trail. PTDC ends at Pluto, which is located about
miles away from Monona Terrace in the village of
Who can ride it? All
parts of PTDC are open to the public. You can voyage anywhere from the Sun
to Saturn (just west of Midvale Blvd. on the bike path), on foot or bicycle
whenever you like. Uranus and points beyond require access to Military Ridge
Trail, which requires purchase of a trail pass from the Wisconsin DNR.
Who created it? We thank our sponsors: Monona
Terrace, Wisconsin Department of Natural
Division and Friends of Washburn Observatory.
Thanks go to Nick Schweitzer for the project concept and working out many
details of planning and installation. Jim Peterson built the sturdy planet
marker frames. Tsela Barr designed the graphics. UW Space Place originated
and surveyed the recreational trail version, designed the scale model,
fabricated the components, and completed the installation. Many thanks also
to John Rummel for help and good advice. Images are courtesy