Our normal class night was postponed for a board meeting of the Frosty Drew Memorial Fund, Inc. [FDMC]. Many topics were covered concerning the day by day running of both the Nature Center and the Observatory. Both units of the FDMC reported a successful year and explained their plans for future activities.

The Observatory has informed the board that we are considering some sort of a small "planetarium" for want of a better term. A planetarium would allow us to operate during rainy or cloudy Friday nights and when crowds strain access to the 16" telescope. An important consideration in favor of a planetarium is that it will give us the ability to schedule groups RELIABLY independent of the weather. It will even allow schools to schedule trips in the daylight hours.

I want everyone to be clear that we do not have a concrete plan. At most we are at the wish list stage of planning where any and all alternatives are being considered. We need to consider a range of options that can be adapted to any amount of grant money that we may receive. And we will need to get substantial funding for any of this to succeed.

Every alternative requires some sort of an enclosure that will allow us to seat a substantial number of people in a darkened space, out of the rain and away from mosquitos. The traditional solution of a small planetarium is appealing, but so are the possibilities of a over head slide presentation or a projection PC.

I have projected astronomical slides on a 45 degree cathedral ceiling. It was stunning. While static, slides have the impact of real versus simulated views. Real sky slide images with and without mythological constellation over lays show details of globular clusters that just do not exist in simulated star projections.

Traditional planetariums have the ability to project 180 degree views of the heavens showing the motions of planets and stars. Projected 180 degree views can be even better than the night sky for identifying the constellations. Modest units are available in the $5000 to $60000 range. They can project acceptable images on domes up to 16 or 18 feet across.

A recent development is a composite of a personal computer tied into a projection monitor. While a 180 field of view array of synchronized projectors is far beyond our reach, a single field projected on a tilted overhead screen is very feasible. Tilting a screen and placing it well above eye level allows people to readily make the connection between simulated and real skies. Unlike traditional planetariums whose optics are rigid and fixed, computerized planetariums can trace star motions over great time periods; show the view at the center of a globular cluster; provide a ride through the solar system and a simulate a host of other situations.

The type of enclosure we would need depends on what type of system we decide that we want. A rectangular "shed" with a steeply pitched roof makes sense for either a photographic slide or PC projector system. It would be like a traditional movie theater but with the screen tilted above you.

Planetarium domes with star projectors come in a variety of forms. Modest domes may be limited to three season use because they do not provide adequate warmth in bitter weather. Domes need not be perfectly spherical. Geodesic domes, both rigid and fabric enclosed, are more than adequate for star simulations. Any dome we consider will be large enough to avoid claustrophobic cramping. Do not image some sort of tiny geodesic tent or an inflated igloos that you have to crawl on hands and knees to enter.

Using the existing Nature Center does not seem like an inviting idea for several reasons. It has no ability to project upwards. In fact, its ceilings are rather lower than average. The number of people who could be seated is quite limited, and the use of the bathroom facilities means that we cannot keep the room adequately dark. Collections, projects and Nature Center materials will compete for space.

We will be considering these plans in the next weeks and months. We would be happy to entertain any ideas which any of you might have.

Recently, a boating tragedy and mystery took the life of John Drew, the nephew of Edwin [Frosty] Drew. His 36' boat was found running with damage to the windshield, but no sign of John. The exact cause of the accident has not been determined but it appears that the boat struck something - possibly a buoy or a towing cable. The staff of the Observatory extend our sympathy to the Drew Family.

-Les Coleman

Author:

Leslie Coleman

Entry Date:

Oct 17, 2000

Published Under:

Leslie Coleman's Log