Planet Trek is Back Up!

May 09, 2013

From now until fall, you can bike all the way from the Sun at Monona Terrace to Pluto in Mt. Horeb on Planet Trek, a scale model of our solar system. Your 23-mile trek through the solar system follows the Southwest Commuter and Military Ridge Bike Trails. At every signpost, learn interesting facts about the planets.

Planet Trek was constructed in 2009 in celebration of the International Year of Astronomy by UW Space Place and its partners: Monona Terrace, Wisconsin Department of Natural Resources, Madison Parks Division and Friends of Washburn Observatory.

UW Space Place shrank 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 the model, the scale is about 200 million to 1. This means that the Sun is a sphere about 24 feet in diameter at Monona Terrace and Pluto is the size of a marble in Mt. Horeb.

Within Madison, you can walk or bike along the Southwest bike path from the Sun to Saturn, just west of Midvale Boulevard. Access to Uranus and points beyond require the purchase of a Wisconsin DNR trail pass for the Military Ridge Trail. For more information, visit the UW Space Place website at

UW-Madison Astronomy Home