Published: September 24, 2009 09:18 pm      

Galileo’s 'scope still good bargain

This year is the 400th anniversary of Galileo’s remarkable telescopic discoveries. Galileo was the first scientist to thoroughly survey the night sky with his crude telescope, discovering the moons of Jupiter, the moon’s craters and mountains, the lighted shapes of Venus and the many faint stars that cause the glow of the Milky Way.

Galileo’s telescope has been duplicated with lenses like those in his original telescope. Galileo’s telescope, magnifying 30 power had a very small field of view; it couldn’t see the entire moon clearly or any patch of the sky of the same width.

Galileo’s telescope with simple lenses had a rather blurry view of Saturn; in one viewing, Galileo thought that Saturn had “ears.” In another, it seemed as if Saturn resembled a jug with handles. It wasn’t until the mid 1600s that Christian Huygens of Holland saw that Saturn had an encircling ring.

In this International Year of Astronomy (IYA), the International Astronomical Union and UNESCO have given their seal of approval to three new telescopes that could give beginners an even clearer view of the heavens than Galileo’s telescope. (These three telescopes will show the rings of Saturn.)

These IYA telescopes have to be very good optically (clear viewing) and relatively inexpensive. Three telescopes have been selected: The Galileoscope, a 50-mm lens telescope that comes in a kit and costs about $15, Celestron’s FirstScope, a 76-mm mirror telescope that needs no assembling, costs $49.95 plus shipping and the 80-mm Bosma refractor (comes with photo tripod) for $198 plus shipping. (Both the Galileoscope and the 80-mm refractor have archromatic objectives (two lenses together to reduce the false colors of a single front lens).)

I have a Galileoscope (sturdy plastic tubes with glass lenses) and have used it several times on a camera tripod. It gives very crisp views of our moon and shows the moons of Jupiter easily. The Galileoscope is best used at 25 power (there are alternative arrangements of the lenses to make a 18-power Galilean telescope or a 50 power telescope).

The Galilean version will actually have a smaller field of view but an erect image. The 50 power version will have a smaller field of view and will be difficult to point, as the Galileoscope lacks a finder. To assemble the Galileoscope, I recommend that a student in the lower primary grades work with an adult.

I will be glad to advise anyone on their Galileoscope assembly. Bring your Galileoscope kit to the Planetarium. To order the Galileoscope go online to www.galileoscope.org. A single Galileoscope costs $15 + $8.95 shipping. If you promise to give a Galileoscope to another person as a gift, you can get two Galileoscopes for $30 with free shipping.

If you order soon, there will be a good chance that the Galileoscope(s) will arrive in 4-6 weeks. I had to wait four months for my Galileoscope (ordered in early February and received in mid July).

As with all beginners’ telescopes, you are warned to never point a telescope at the sun. I have my Galileoscope at the Planetarium if you would like to see how it shows the distant hills.

The Celestron FirstScope has a 3-inch wide mirror telescope, attached to rotating stand that will fit on a table. The FirstScope comes with two eyepieces, one for 15X and the second providing 75X.

(There is an accessory kit available that includes a finder and carrying bag.) I don’t have a FirstScope but there is a good review of this telescope in the September Sky & Telescope magazine (go to www.SkyandTelescope.com and search for FirstScope).

The FirstScope is available through the mail or at any Celestron dealer (www.celestron.com). The FirstScope has bigger (wider mirrors, more light) “relatives” which are more expensive, made by Orion Telescopes (www.Oriontelescopes.com).

The Bosma 80-mm refractor (lens telescope) can be used as a spotting scope (upright image) and can be attached to a 35-mm SLR camera (film or digital) with the right adapter. It has a 500-mm focal length so it can be used as long distance telephoto lens.

It comes with two very good eyepieces and camera tripod (to which telescope can be mounted). It also comes with a finder scope and a front lens solar filter. It is available through Astronomics in Norman, Oklahoma (www.astronomics.com).

I have a similar telescope that I purchased years ago from Orion Telescopes with similar features at the same price but without a tripod or solar filter.

The moon is just past first quarter (then appears half full), offering good views of its craters and mountains with binoculars held steadily or with a telescope.

Late tonight the moon is at apogee, meaning farthest from the Earth, with the center (of Earth) to center (of moon) distance of over 250,000 miles.

This coming Saturday, we have the Harvest Moon that provides extra evening moonlight for the following four nights.

This name comes from the time when farmers lacking machinery harvested their crops by hand tools, working in the early evening by the light of the Harvest Moon.

Our last shows of “White-Blue Ball and Pale Grey Dot” are shown today at 4 p.m. and 7 p.m. in Tawes 302. Next month’s program is “Bare Eyed Astronomy,” all about sights and changes visible to the eye. Call (301) 687-4270 for road directions.

Comments and questions are welcome; phone (301) 687-7799 or email rdoyle@frostburg.edu .