One of the most mind boggling aspects of astronomy is the vast distances involved. How does one comprehend 100,000 miles, let alone the billions of miles more common in astronomical measurement? Even our own solar system's distances are hard to imagine. How far away is 93 million miles? And thats just the distance to the Sun, Pluto is much, much farther. Well now you can take a walking tour of the solar system that brings such huge distances down to ?earthly? levels! This vacation, think about visiting the Sagan Planet Walk in Ithica New York.

For over 30 years, Ithica was the home to one of the most well known and loved astronomers, Carl Sagan. Sagan strongly believed in popularizing astronomy and all sciences. He believed that the general public was interested in science if it could be presented at a level in which it could be understood. Science need not be all bazaar looking equations. He always believed there was a way to bring the cosmos down to Earth. From his multi-part documentary TV series Cosmos, to his many books, Sagan preached astronomy until his death last year. In his honor, the Sagan Planet Walk was dedicated last November.

The theme behind a planet walk is to put the distances and sizes of the Sun and planets into perspective. The plan for this planet walk was developed in 1995 by Charles Trautmann and Robert Orrange of the Science Center in Ithica. A local artist designed the monoliths and funding for the $100,000 project came from donations.

The scale of the Sagan Planet Walk is 1 to 5 billion and consists of ten planet stations. The entire solar system stretches for 1200 meters, from the Sun at the Ithica Common Mall to Pluto at the Science Center itself. Mercury, the closest planet to the Sun, is 12 meters from the Sun, Earth is 30 meters and Neptune is 7 blocks distant. Each ?planet? is mounted on a monolith with a plaque describing the planet's physical characteristics, and some high resolution color spacecraft images.

The planets are also scaled to size, which truly adds perspective to the planet walk. Because the entire distance scale (from the Sun out to Pluto) is shrunk to 10 blocks, the sizes of the planets must be quite small to fit to scale. Earth is a mere 2.5 mm across. Jupiter is 29mm and Saturn is 24mm.

If you don't mind a bit more walking distance, there is another planet walk in Boston. This one is on a larger scale  2.5 cm to 100,000 km. Each of the planets, cast in bronze, is scaled to size and because the scale is larger, more detail can be added, cut in by laser. The Sun's 3.6 meter sphere is located at the Charles Hayden Planetarium Pluto is nearly 15 km away. It takes about 5.5 hours to walk this tour.

For more information of these planetary attractions, you can find the Sagan Plenat Walk at http://www.sciencenter.org/  or phone at 607-272-0600. For more information on the Boston Community Solar System, go to http://www.mos.org or call 617 723 2500.

Constellations

The Solar System