Homeschool Astronomy on a Budget

Initially in astronomy, there is not a huge financial investment. Just go outside and look up. Instant success. You see stars.

But then, there comes a thirst for more. What are the stars made of? Why do they move in the sky? And what's all this winking and twinkling about? Questions you haven't thought of since you wore Superman underwear. These worthy inquiries are easily answered in a trip to your local library.

Then it really happens. You find out your very own town has an astronomy club. "Come see the stars!", They entice you! "Free Star Party this Saturday!" Armed with a thermos of hot cocoa and cookies your wife made, you tramp up Star Party hill. And you see it all – not just the stars and galactic nuclei, but all those TELESCOPES.

WOW.

Your wife is not happy about trading the car for a telescope. Call her crazy, but a telescope doesn't pick up the groceries or take kids to ballet. In fact, it's a gadget to look at things that have been around since before either of you were around. You're just all-fired up on doing it now. And yes, most of those sparkly things up there will be up there when you retire, so why not just wait until then?

"Because the purpose of life to experience happiness, which can only be experienced in the present moment," explains the Dalai Lama, quite patiently.

"But the Dalai Lama does not have four children and two mortgages," your wife counters. So what are you to do?

Astronomy club telescopes are available for members, but what if you want something of your very own right now? (We are, after all, Americans.) And you want to share astronomy with your kids, and you're not likely to share an expensive telescope with those grubby hands. There must be a happy alternative. But what?

Go get a raft. The inflatable kind you have lurking somewhere in your garage already. Set it up on the grass, and pull out a pair of binoculars. A good pair. Add cocoa and cookies, and you have an instant star party worthy of any amateur astronomer.

How to pick a good pair of binoculars? Here are some ideas that may work for you (excerpted from Backyard Astronomer's Guide by Dyer and Dickinson):

Larger main lenses mean brighter images, but for most people, a 50mm lens is a practical handheld limit. Binoculars with a 7mm exit pupil are easier to bring to correct position in front of the eye, an advantage for young people and beginners of any age.

Higher magnification means better resolution, but it also means more stringent optical-quality standards to produce good images. It also results in amplified jiggling during handheld operation. This factor alone limits binocular magnification for handheld astronomical viewing to 10x.

Put it all together, the most popular sizes are 7×50 and 10×50. If you prefer smaller and lighter, go for the 7×42 or 8×42. Why not just go for the 10x50s, since biggest means best? Well, because aiming and observing through binoculars at night is much easier for some than others. In our experience, 7x50s are much easier to use. On the other hand, 10x50s yield fainter stars and more Moon and celestial object detail. More detail makes sense, but why are dimmer stars more apparent? Part of the reason is that the smaller exit pupil helps avoid the edge-of-eye aberrations (producing sharper stars), but mainly, it is that the higher magnification in effect spreads out the sky background, darkening it in the process.

Roof prism binoculars are more compact than porro prism in sizes under 42, and are generally more costly. For general astronomy binoculars at a reasonable price, we recommend porro prism models in 7×50 and 10×50.

RECOMMENDATIONS for general astronomy glasses:

These two stand out, both in the $ 200 range: Vista 10×50 by Orion and Ultima 10×50 by Celestron. Both are 27 ounces (exceptionally lightweight for 50mm binoculars) and very sharp 5.3-degree fields and good eye relief. In the $ 100 range, the Bausch & Lomb 10×50 and 7×50 Legacy are ideal beginner binoculars for astronomy. A lightweight tripod and L-adapter are great additions for an upgrade. Go enjoy your night sky!


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