Remember the first time you saw the Milky Way? It was no doubt a very clear and moonless night. You might have been in the desert or at a high altitude, where the atmosphere didn't impede the sight of millions of stars. But the truth is you probably only saw about 2,000 stars; there are only around 6,000 stars with a brightness magnitude 6 (the limit at which a star can be seen with the naked eye) visible from Earth.
Nonetheless, the heavens have intrigued mankind for millennia, and today's modern optics allow us to easily explore the sky, the Moon, planets, stars, nebulae, and galaxies that make up our universe. Here's how to get started stargazing.
Ease into a Stargazing Hobby with Research
Take a trip to your local planetarium to start learning about our solar system, galaxy, and our place in the universe. You can also find a local stargazing club; attending a meeting is an excellent way to check out equipment and absorb some of the enthusiasm of hard-core star buffs.
A night sky that is clear and moon-less is the perfect time to step out and look up at the stars. You'll want to find an open area where the horizons are far away, and a spot that is isolated from the light pollution of metropolitan areas. With a star map like the pictured SkyAtlas 2000.0 ($35.96 with $1.97 s&h, a low by $1) in-hand you'll be able to recognize constellations like Ursa Major, Orion, and Aries. This map features 28 500mm-wide charts covering both the north and south hemispheres that will help you identify planets in our solar systems like Mars, Venus and Jupiter. You can also download a variety of star map apps that help identify constellations with ease.
The Next Step in Stargazing: Springing for Cheaper Optics
Many astronomers prefer a good pair of binoculars over a telescope because they're lighter, less expensive, easy to carry, and a snap to operate. They also offer a wider field of vision that'll allow you to get the big picture and scope out many stars. With an inexpensive pair of astronomy binoculars, you should be able to see galaxies, nebulae, star clusters, the moons of Jupiter, and more.
There are a couple of pertinent numbers when shopping for your binoculars, usually expressed as 20x80 mm. The former number is the magnification, the second number is the size of the lenses at the opposite end of the eyepiece. For astronomy glasses, the larger the second number the better because a larger lens gathers more light, and therefore provides a better image.
Be aware, however, that the larger the lens, the larger (and heavier) the binoculars. Many people realize that trying to hand-hold larger models is difficult. The best solution for using large lens binoculars like the above-pictured Celestron SkyMaster 71018 20x80mm Binoculars ($99.94 with free shipping, a low by $30) — which have multi-coated optics, Porro prisms, a large aperture, and long eye relief for eyeglasses wearers — is to also pick up a sturdy, yet portable tripod. The Celestron 93607 Alt-Azimuth Tripod for Binoculars ($82.98 with free shipping, a low by $8), pictured at right, has sturdy aluminum construction, flexible slow-motion altitude and azimuth controls, and an accessory tray.
Move On Up to Something Stronger and More Advanced
Most sky gazers who really get the bug, however, will want to soon broaden their view with a telescope. When shopping around for a model, keep in mind that any stargazing telescope needs a stable mount that moves smoothly when adjusted. It should also hold position while the focus knob is being tinkered with. What's more, your telescope should be light enough to carry, so that you can transport it easily to the best vantage spots. Sky and Telescope magazine reminds us that "how good an astronomer you become depends not on what your instrument is, but on how much you use it."
And to get the most of out a telescope, you should probably know how it works: A telescope collects light via a lens or a mirror; the diameter of that lens or mirror is called the aperture and determines how much light it can gather and therefore how sharp the resulting image is. Bigger is better, most of the time. For example, the surface area of a lens 8" in diameter is four times that of a 4" lens, so the image will appear four times brighter.
The magnification with which you see the image is determined by the lens in the eyepiece. The greatest magnification you can achieve is roughly 50 times the aperture of the lens or mirror, so a telescope with a 4" lens has a maximum magnification under ideal conditions of 200x. Many inexpensive department store models promise this maximum magnification, but can't deliver, since it takes very fine optics and perfect conditions to make it happen.
Decide Which Telescope is Right for You
There are three common types of telescopes: the reflector, the refractor, and the Cassegrain. The type that usually comes to people's minds when they hear the word "telescope" is the refractor, which is shaped like a pipe with an eyepiece on the end like on the pictured Orion Observer 70mm Altazimuth Refractor Telescope ($109.99 with $9.95 s&h, $20 off). This rugged telescope comes complete with a mount, weighs just 6.5 lbs., and serves well as a first telescope. This type of refractor provides an image that remains sharp under high magnification. However, larger aperture models tend to become long and heavy, and unwieldy to handle. A very tall, very stable tripod is needed to support one of these. Moreover, this type of telescope isn't great for deep space exploration, since its field of vision is rather narrow.
The reflector telescope, well, reflects light gathered by a concave mirror. The image is bounced back up to another mirror mounted at an angle within the tube, then to an eyepiece on the side of the tube. This type of telescope is more compact; its length is usually eight times or less the aperture of its mirror. This means it is more mobile, and less expensive than a refractor telescope. A reflector telescope, like the Orion SpaceProbe 130ST Equatorial Reflector Telescope ($279.99 with free shipping, a low by $15) does take occasional maintenance to keep the mirror properly focused, however, and the mirror may need to be re-coated if it clouds up. Also, the image appears upside down, so it doesn't work well for watching earthly activities like hot air balloons on the horizon.
The Cassegrain telescope is a combination of reflector and refractor models. It uses lenses and mirrors to provide a better image with a larger aperture. Cassegrain telescopes are long-focus but is very short, light, and easy to transport. However, it too may need the occasional refocusing of its mirror. The Celestron CPC 1100 StarBright XLT GPS Schmidt-Cassegrain 2800mm Telescope with Tripod and Tube ($2,820.48 with free shipping, a low by $179) is a serious tool for some serious deep-sky gazing. It has an 11" mirror, a fully computerized dual fork arm altazimuth mount, GPS alignment, and weighs a hefty 110 lbs.
There are, of course, a number of other choices beyond these basic telescopes. Modern GPS technology and computer chips have brought to market telescopes that make finding your target in sky as easy as selecting it from menu. However, such equipment is rather expensive, and diminishes the thrill of the hunt.
Once there was a time where all one could do was wonder about the stars above. Now the technology to see and understand the celestial sky is readily available. From Jupiter's rings to passing comets, from the Milky Way to galaxies light years away, the rich display of the night sky is there for your illumination. All it takes is a little darkness, a viewing aid, and the same curiosity you had as a child.