By Jon Stewart-Taylor
Amateur astronomy covers a very wide range of skills and knowledge. Everyone brings their own interests, and therefore everyone focuses on different things. But, there are some fundamentals to be learned, and it can save a lot of time and frustration if you have a guide when you get started.
This page is intended to be a quick overview of how to start right in astronomy. I'll touch on a lot of topics briefly, and links in the article will take you to Recreational Astronomer pages which cover the subject in much greater detail.
Why unaided-eye first? Lots of reasons.
First is that it takes almost no equipment. Just get an introductory book or planisphere (a rotating chart which shows you which stars are out at a given time and date) and possibly a good set of star charts, and you're ready to go. This means a very low cost to start. If you do get charts, they can be used when you're ready to move up to binoculars or a telescope.
Second, you can observe at any time, any where. Every clear night is a chance to observe, and you don't have to worry about setting anything up, or losing or damaging expensive equipment.
Finally, the skills you learn are not only satisfying in and of themselves, but they're an important foundation for observing with binoculars and telescopes. There's an awful lot of space out there. It does no good to have someone say "look at beta Cygni" if you don't know where Cygnus is in the sky.
What can you observe with just your unaided eye? Lots!
What about "planetarium" software? It can be a help learning the sky, and especially in planning observing sessions, but it does have a major drawback: most computers don't like being outside in the cold and (when dew falls) wet, so it's hard to take it out under the night sky. If you've got a PDA such as a Palm Pilot planetarium software can be very useful.
Binoculars are a good next step. They take you about halfway between unaided eyes and a telescope, and are very quick and easy to use. They help you to learn the sky, and teach important skills you'll use with a telescope finder. 10x50 binoculars may be the best for beginners under suburban skies, but just about any binoculars you already have will probably give tolerable results. To get the most out of binoculars you'll need good charts.
The main drawbacks to binoculars are low magnification, and that it's hard to share a view with other people unless you put the binoculars on a tripod. And, they just don't have the "cool factor" of a telescope.
What to observe with binoculars? Everything except the sun. You'll see more detail on the moon through binoculars than you'll see on any planet through any telescope on earth, amateur or not. You can detect Saturn's rings and Jupiter's moons. You can observe double stars, star clusters, nebula, and galaxies. In fact, some star clusters are so big that binoculars are really the best things to observe them with.
First: Don't buy a telescope at a department store or deep-discount store! Why? Because most of them are unusable. They may have good optics. However, the finders included are often so bad it's next to impossible to find anything other than the moon. And, even if you can find something, the mount is usually so badly constructed that it won't hold the scope steady enough to look at what you found.
The advertisements for these scopes often claim magnification of up to 600 power. The laws of physics put a limit on the maximum useful magnification of 2x per millimeter or 50x per inch of the objective (main lens or mirror). This means for a 60mm telescope (typical size for a department store telescope) the maximum useful magnification is only about 120x. Any power much over that will give increasingly blurry views.
These scopes are frustration in a box.
Second: The best telescope is the one used most often. Think about where you want to use it, where you're going to store it, how far you have to carry it, and most important of all, what you want to observe. See our article about buying telescopes for more information.
Do lots of research. Attend several of the local public observing sessions, and look through other people's scopes. Amateur astronomers are amazingly generous with their time and equipment, so take advantage of them. Read as much as you can, on the Internet and in books and magazines. Expect to spend a 1/4 to 1/3 of your money on accessories such as charts, eyepieces, and finders.
Before you buy your telescope, i strongly recommend you buy a book: Turn Left at Orion, available at Orion Telescopes or Amazon.com. It's simply the best book out for beginners with a new scope, and not a bad reference for binoculars. Read the chapter called "How to Run a Telescope".
What about those computerized "goto" telescopes, which promise to find all celestial targets without you having to know what or where the objects are in the sky? They can be a good choice, since once you get them working you'll be able to find things sooner than if you learn "the hard way". These telescopes do still require a minimum knowledge of the sky to be able to tell their computers how to get oriented, and they're usually more expensive than their computerless counterparts. Again, talk to people who have similar scopes to learn the benefits and drawbacks before you buy your own.
If your budget is less than $200, i strongly recommend binoculars and a tripod.
In the $200-$400 range, i recommend a 4" Dobsonian reflector with a unit-power finder such as a Telrad®. That is enough scope to keep you busy for at least 2 years, and the accessories and experience will transfer to your next scope. Both Orion Telescope and Stargazer Steve make very good scopes. The Orion is currently priced at about $250 including shipping, and includes decent eyepieces and an above-average finder.
For $400 and up, get a Dobsonian reflector in the 6" to 8" size. That should keep you busy for many years, and might even be the only scope you ever need. There are several manufactures who make scopes in this size and price range.
If you have over $600 to spend, there are a lot of options which open up, particularly with motorized and computerized scopes. While i don't personally feel they're the right choice for a first scope, they may work for you. Do your research first.
Remember i said to save about 1/4 to 1/3 of your budget for accessories? You should get a red flashlight (although you can make one if you prefer), a good star atlas (such as Will Tirion's Cambridge Star Atlas), a Telrad® or other unit power finder (even if your scope already has a conventional finderscope), and probably an extra eyepiece or two. You already bought Turn Left at Orion, right? It's included in the total.
Observe often, and learn the sky. Binoculars are a good first instrument. Everybody's different, and my recommendations may not be perfect for you. Do a lot of research and try out lots of telescopes at public sessions before you buy. Above all else, have fun! Amateur astronomy is about enjoying the beauty of the heavens.
© 2006 Jon Stewart-Taylor