Studying Astronomy at Home
by Bill Lovegrove
Astronomy is a wonderful field of science for at-home study. After all, the laboratory is spread out over everybody's back yard. People of all ages can learn, appreciate, and enjoy viewing the wonders of the heavens. For a Christian, astronomy has special significance. It is the heavens that particularly declare the glory of God (Ps. 19:1). If you and your children want to learn some astronomy on your own, the following suggestions will help you get started.
Two major amateur astronomy magazines, Astronomy and Sky and Telescope, are available at many libraries and bookstores. They are full of good information and advice, including beautiful photos, monthly sky charts, and notes about special things to watch for in the sky. You can read the magazines at the library, but if you intend to seriously pursue astronomy for several months, consider subscribing instead. When major events occur, such as the appearance of a comet, the magazines will have full details of what to see and when and where to see them. If you are considering buying a telescope, the magazines will be full of good advice. For people exploring astronomy on their own, these magazines are almost indispensable.
Here are two of my favorites among the many books written on astronomy for amateurs. One is 365 Starry Nights by Chet Ramo (Prentice Hall, 1982). For teens and adults, this first book covers astronomy in short, easy nightly viewing assignments. Each night's assignment is self-contained. You can start any time of the year; it's no problem to skip nights or to do several in one night.
The Stars: A New Way to See Them by H. A. Rey (Houghton Mifflin, 1976) is the second book; it is a classic written for children by the author of the "Curious George" series. For an interesting discussion of the biblical references to astronomy, see Stewart Custer's book The Stars Speak: Astronomy in the Bible (Bob Jones University Press, 1977).
The First Steps
Begin with what astronomers call "naked-eye" astronomy in your own back yard. No telescope is needed--just your own two eyes. Learn your way around the sky and become familiar with the major landmarks. Astronomy is best learned in little chunks spread out over a long time. Eclipses come sometimes years apart. Planets go through good viewing months and bad viewing months. The nightly constellations change seasonally. There are interesting things to see every night, but they are different things every night. Learn to take what the sky gives you. Week by week, month by month, you will gradually discover more and more.
Start by learning the major constellations. The constellations are the map by which astronomers find everything else in the sky. Even young children can learn the most familiar, such as the Big Dipper and Orion. Since the constellations change seasonally, it takes a year to see them all if you observe only in the evening. The Moon and the planets are constantly moving around. You need help to know when and where to look for them. The sky charts published in the major astronomy magazines are the easiest way to get this information. Most important of all, spend a lot of time outside looking at the sky, right from the start. Get in the habit of looking up every time you are out at night. The joy of astronomy is in the seeing.
A Dark Sky
A little bit of stray light ruins the view of some of the most interesting things in the sky. Modern cities put so much "light pollution" in the sky that viewing from within a city is nearly impossible. Many children, for example, have never seen the Milky Way. It's not hard to see when the sky is dark. From a city view, however, it's almost impossible to see. Even a telescope doesn't help much. The only solution is to go somewhere dark. Even if you go to a dark place, the Moon provides plenty of light pollution of its own. When the Moon is full, things get hard to see. Plan a trip out in the country to a dark spot. Pick a night when the Moon comes up late or is new. You'll be amazed at the view!
The Big Ones
Don't forget the Sun and the Moon. There's no problem finding them in the sky! There is much to learn even about them. Sunsets, rainbows, sundials, eclipses, phases of the Moon, tides--all of these are good subjects for study and provide abundant possibilities for projects. Solar and lunar astronomy are still active fields of research even among professional astronomers today.
Once you know your way around the sky, binoculars will open up a whole new level of viewing. You will be able to see galaxies, nebulae, craters on the Moon, and a host of new stars. The sky charts will help you find them. Binocular sizes are marked by two numbers AxB (such as 7x50). The A is the magnification (things look 7 times larger). The B is the lens size (the main lens is 50 mm in diameter). More important is a large B value for a bright easy-to-see image. The magnification is not as important. A common size that is good for astronomy is 7x50.
If you live near a planetarium, you have a unique opportunity to get a guided tour of the sky. Be warned that many planetariums now do a variety of music/light shows and educational programs that may not be related to astronomy. However, nearly all of them still do simple tours of the night sky. Visiting a planetarium show and then going outside yourself is a great way to start.
After taking all those steps--and not before--consider getting a telescope. Until you know your way around the sky, a telescope is more frustrating than helpful. Unless you get a good telescope and learn how to use it, you will experience nothing but frustration. In choosing a telescope, consider the following:
- The higher the magnification, the harder the telescope is to use. At 20x (meaning the view is magnified 20 times), the telescope becomes difficult to aim without a small "finder" scope to assist. At 100x, things move out of the field of view so fast that the telescope is hardly usable without a motorized tracking mount. For home astronomy, 100x is enough, but you can see a lot at 30x, including the rings of Saturn, the moons of Jupiter, the Orion nebula, craters on the Moon, and much more.
- Aiming the telescope is an important consideration. Good telescopes have sturdy tripods and mechanisms that allow the telescope to be slowly and smoothly panned across the sky and to stay in place once they are aimed. Cheap telescopes are almost impossible to aim and keep aimed.
- Larger lenses or mirrors are much more important than large magnification. Larger optics mean a brighter, easier-to-see image. Telescopes below about two inches in diameter are not very useful. Three inches and up is much better.
Astronomers view cheap "department store" telescopes with scorn. These telescopes boast uselessly high magnification (often 400x or more) but have tiny optics and flimsy mounts, which make them nearly impossible to use at even low magnification. The astronomy magazines carry numerous advertisements for good telescopes. A number of good ones are available in the $150-$300 range. You might find a used one for much less. What if you already own a wobbly telescope, or you find a deal you can't resist at a garage sale? Astronomy published a story in the January 1997 issue called "How to Redeem a Department-Store Telescope." By doing a little woodworking, for under $50 you can build yourself a better tripod and mount and make the telescope far more useful.
Astronomy is a wonderful family activity. It's a subject you can explore completely on your own, with no previous experience necessary. Children of all ages can be involved. Go exploring as a family and learn together. Discover the excitement of astronomy.