To begin hunting in the night sky, rely on your eyes and a pair of binoculars
As the holiday season approaches, thoughts of gift-givers (and gift-getters) sometimes turn to telescopes for touring the night sky. But like buying a puppy, this is a step that calls for more knowledge and forethought than people sometimes bring to it.
Buying a telescope won't make you an astronomer. It won't, by itself, introduce you to the wonders of deep space. It certainly won't offer grand visual spectacles. Astronomy is not a buying hobby, at least not at first. It is a learning hobby.
I've been helping people get into astronomy for 25 years, and I've seen all the missteps. I'm convinced that the first place to nurture a budding astro-interest is at the library. Look for guidebooks to the naked-eye stars and constellations. Disclosure: I work for Sky & Telescope and Night Sky, the two magazines with the best sky charts anywhere, in my opinion; I helped design them.
Learn how to use the charts, and take them out into the night with a dim red flashlight to read them. Piece by piece, learn the geography of the naked-eye heavens over your yard just as well as you know the continents and oceans of Earth.
Only then will you be prepared to find and zoom in on points of interest hidden in the depths.
But don't buy a telescope yet! Because the best "first telescope" may already be lying around your house. It's a pair of binoculars.
Good binoculars will get you about halfway from the naked-eye view to what you can see in a good amateur telescope. But binoculars are much easier, what with their wide, right-side-up views. Moreover, the skills you'll learn using binoculars to find things with celestial charts and guidebooks are exactly the skills you'll need to use a telescope well.
Let's take a trial run.
Face northeast in early evening and look very high. There you'll spot a vertical zigzag of five moderately bright stars, a big W standing on end. It's about as big as your hand held at arm's length. This is constellation Cassiopeia, supposedly an ancient queen of Ethiopia, or perhaps her chair.
Counting down from the top, stars 1, 2 and 3 of the W are the brightest. Stars 3 and 4 point downward and a bit to the right. Follow the line they make for twice as far on down, and you're at the Double Cluster in Perseus, one of November's deep-sky wonders.
In true darkness, the Double Cluster can be detected with the naked eye as a small, irregular patch of glow. Under Greater Boston's light pollution it's invisible. But binoculars will do the trick.
You need to know how big a view your instrument gives compared to the sky chart you're using. Cassiopeia shows you. Scan it with your binoculars from top to bottom. You'll probably find that your field of view is about the size of the circle drawn here on the chart.
Locate stars 3 and 4, sweep down beyond the line they make and there amid the starry pinpoints is the Double Cluster: an overlapping pair of cottony fuzz-patches sprinkled with stardust.
What, exactly, are you seeing? These are twin nests of hundreds of young stars that have not yet dispersed from where a gas cloud gave them birth. Both clusters lie 7,300 light-years away, and both are about 13 million years old. That may sound pretty old, but it's less than half a percent of the age of our 4.6 billion-year-old sun, Earth, and solar system.
Continue on a little farther in the same direction, and see if you can make out the smaller, fainter cluster Trumpler 2. Despite its dimness, it's closer, about 2,000 light-years distant. Its stars are also more mature, age about 80 million years.
Get good charts and a binocular guidebook (my favorite is "Binocular Astronomy" by Craig Crossen and Wil Tirion) and you'll be on your way to a lifetime of exploring the heavens.
Oh, and when you finally buy a telescope, don't skimp. Avoid the semi-toy scopes often sold in retail outlets. You want high-quality optics, large aperture (size), and in particular, a heavy, rugged, wobble-free mounting.
Alan M. MacRobert is a senior editor of Sky & Telescope and Night Sky magazines in Cambridge (SkyTonight.com). His column appears the first Saturday of every month. 
