The Starhopper is a potato cannon. The tube is 10 inches across and four feet long, and it weighs about 25 pounds. Most of the weight (and the expense) is in the big mirror at the base, a glass disk 8 inches across and about an inch and a half thick. The curved surface of the mirror is ground and polished to a parabolic shape accurate to a few millionths of an inch. The tube itself is just laminated cardboard, a Sonotube used as a form for concrete columns.

The tube sits on a lazy Susan-like rocker box that allows it to be aimed just like a cannon. The tube balances on a pair of metal trunnions that rest in half-circle cutouts at the top of the rocker box. The rocker box steers (rotates in azimuth) and the tube tilts on the trunnions (rotates in altitude).

Telescopes like this are generally called Dobsonians, or simply dobs, after innovative telescope maker and erstwhile monk John Dobson. Strictly speaking, the optical design was invented by Isaac Newton, so optically it's a Newtonian. Dobson is usually credited with the design of the mount and, more importantly, with an egalitarian philosophy of simple and inexpensive telescope construction. Reflecting the no-frills utility of these instruments, they're also sometimes called light buckets.

Before dobs, the typical amateur instrument was a small aperture, long focal length refractor like the Sears model, which my dad bought around 1970. As a kid, I got my first look at Jupiter and Saturn through this telescope. The optics are pretty good for a department store scope, but as with today's instruments in this class, the flimsy mount makes it difficult to aim, and the small aperture limits its light grasp.

The TV-85, at the other end of the quality spectrum, is the two-seater sports car of the group. I bought it in 2004, just before the Venus transit, so that I'd have something more portable than the dob. It's also better suited for solar observation and astrophotography. Serious amateurs take instruments of this quality for granted now, but they are still by no means common. The serial number on mine is in the low 2000s, and the instruction manual is autographed by Al Nagler, Tele Vue's founder.

Photons from distant astronomical objects are falling on the ground like rain all around us. With something bigger than the lens of our naked eye to collect and focus them, we can see thousands of things in the night sky that are otherwise too dim or too small. This is what telescopes are for.

If you're thinking about getting a telescope, do some research first. Competent first scopes can be found at photography and nature stores, but for more advanced equipment, seek out a telescope dealer, even though they may be more difficult to find. I bought both the dob and the TV-85 at Company Seven, a nationally known dealer whose storefront, fortunately for me, is just a few miles from my house.

Avoid the cheap, toy-like telescopes sold in department and big box stores. The packaging for these scopes often features Hubble Space Telescope images and makes deceptive and wildly unrealistic claims about magnification. You'll be disappointed.