About the Harken Astronomical Observatory

We have something very unique in the new Pewaukee Public
Library. Our astronomical observatory may be the only one
in the nation on a public library.

It adds an interesting, educational and fun dimension to our library. The Observatory provides education and brings the wonders of our incredible universe to families of our community in the friendly and casual environment of our new library. It is a hands-on experience with rare access to high tech and powerful equipment.


The Telescope Dome

The dome was made in Australia. It is 12-feet in diameter. A motor drive turns it remotely on a series of ball bearing wheels that ride in a track. There is a slit to look through that opens to view the night sky.


A Refractor vs a Reflector Telescope

There are two types of telescopes — refractors and reflectors. A refractor has a tube with multiple lenses that you look through at one end—light enters at the other. Refractors are usually small in diameter. They are excellent for brighter objects like the moon and planets.


Our telescope is a Meade 12-inch diameter Schmidt-Cassagrian reflector. A reflector has a large mirror in the back of the telescope. Light enters through a glass window in the front, reflects off the large mirror to a smaller mirror in the center of the glass, and back to a hole in the big mirror to interchangeable eyepieces that determine the magnification.

The larger the telescope’s diameter the more light that is taken in, which allows us to see deep sky objects that are very dim. A 12-inch mirror will allow us to view nebulas and galaxies, as well as the moon and planets. A computer will guide and GPS will position the telescope A computer guides the telescope and a GPS (global positioning system) tells it where it is. An azimuth motor keeps the telescope tracking on the object even though the earth is rotating at about a thousand miles an hour.