As backyard observers may know, some modest telescopes lack the optics or aperture to cleanly resolve deep-sky objects like nebulae, star clusters, and galaxies. This leads to fuzzy images, often ...

In the December 2011 issue of Astronomy, I wrote “Wander winter’s deep sky,” which was a guide to great celestial sights through five sizes of telescopes: 3- to 4-inch, 6- to 8-inch, 10- to 12-inch, ...