December 12, 2017

Starting into Astronomy: To Buy (Or not Buy) a Telescope?

   One of the questions I most frequently recieve is “what kind of telescope should I buy as a beginner or for a child?”  Certainly there is a lot of pitfalls to avoid, and very few hands on resources to test drive a potential new scope.  When I first started into astronomy as a kid, there were virtually NO guidance were I lived in rural Northern Maine.  All I had was an Old Farmers’ Almanac, outdated books that still showed pencil-shaped rocket ships, and a pristine dark sky in my back yard.  I barely knew how to find the moon, let alone find fainter objects and point a telescope at them.  I didn’t know how to pronounce certain stars and constellations properly, and continued with my ad hoc soundings until I heard them actually said years later.  When I turned 7, I recieved a thrilling present: a 40mm Newtonian reflector! I could hardly wait to turn it loose under dark skies that warm summer night.

   However, as darkness approached and I sat my first scope out on our front lawn, some shortfalls became apparent.  The tripod mount on which the tube rested was filmsy; one push or gust of wind would move it off position.  The finder was a simple plastic tube which wouldn’t align with the scope.  The eyepieces were tiny; I had no practice looking through them. Parts were plastic and promptly broke with first use. 

    Then there was the issue of the sky; was that red speck a star or Mars?  I realized I had no idea.  There was no bright Moon that night, and it dawned on me that I had no clue were anything was.  I was like Mr Magoo, aimlessly wandering the universe.

    This first hands on experience turned me off of telescopes for years.  I doubt if that first scope ever saw the light of anything fainter than the Moon.  And from talking with others, mine is not a singular experience.  “We got a telescope for Christmas, but we only tried to use it once,” is a popular refrain. Sometimes, these are expensive computerized affairs.  I have two “Go-To” scopes, and while handy, neither has relieved me of my mental database.  Both have there own quirks and I never seen one that was truly “point and shoot”, such as when the scope aims at the ground when slewing.

   On its most basic level, starting into Astronomy is free.  I would advise anyone interested to check out some star atlases from the local library and learn the constellations.  Watch the planets and the moon and see what they do night to night.   This will give you the basic hands on knowledge necessary to find your way around the night sky from season to season.  Such activities as meteor and satellite tracking can also be rewarding and require no specialized equipment.  One of my most memorable observing experiences were watching the Leonid meteors from the deserts of Kuwait and being suprised by the Northern Lights from Maine.  I mention these because neither involved a telescope.

   Eventually, most enthusiasts move on to optics.  Binoculars are a good intermediary between naked eye and telescopic observing.  Hand held instead of mounted, they require no set up, and give a wide field of view.  Many households already have a pair kicking around. A good pair of 7×50 binoculars generally cost aroung 100$. The “7″ stands for the magnafication and the “50″ is the primary aperture described in millimeters.  For any optical instrument, the aperture size is the main consideration, not magnification. This feature rates an instruments light glathering ability. Avoid cheap department store scopes promising “x1000!” These lead down the pathway to frustration.

   What can you see with binocs?  A first quarter moon will appear brilliant, with scores of impact craters and maria. The planet Venus will show a disernable phase, and the moons of Jupiter will change position from night to night.  The Milky Way will break down into a shimmering trail of stars, and brighter Messier objects like the Andromeda galaxy and the Orion nebula will show structure. Binoculars are still the preferred tool for many comet watchers, because a bright comet can often cover more than 10 degrees of sky.  Most seasoned observers, myself included, still keep a pair of binocs handy for quick spotting.

     Ready for a telescope?  Scopes come in a bewildering array and none come with an instructor for training.  Most users can recant a long list of knowledge gained through a string of mistakes. I’ve run personnal and university telescopes and observatories, and every last one has its own quirks and peculiarities.

   Again, a word on “goto” scopes.  I own two scopes with computerized systems, and they can be very handy for locating faint fuzzies.  I don’t know of any owner that would give theirs up.  However, in my experience, none are totally fuss free;  some astronomical troubleshooting experience is still required.  Batteries die; I am still an advocate of being able to locate objects via star-hopping with an atlas and a red flashlight.  I still insist any computerized scope I purchase can be used manually, if necessary.  If one of these ended up under your christmas tree,  there are numerous on-line chat forums dedicated to these exclusively or, better still, search out your local astronomy club.  The same advice also holds true for telescope purchasing in general; astronomers love to talk about their gear and will show you the ropes.

   Whats a good first scope?  All telescopes fall into two catagories; reflectors and refractors. A reflector uses a series of lenses and mirrors, a refractor uses lenses only, and has the classic “look” of a telescope familiar to most people.  Reflectors, however, are inch for aperture inch, cheaper to construct, and many amateurs grind their own mirrors. A slight disadvantage a reflector has is the secondary mirror on most presents an obstruction and causes some light loss, and for optimal performance the mirrors have to be aligned, or collimated.  This can vary from scope to scope; some scopes I’ve seen need collimating every viewing session, others only once a year or so.

   A classic starter refractor is a 60mm aperture scope. This was my first serious telescope as a teenager.  With it, I could see the rings of Saturn and study the moon in detail. It had a simple, alti-azimuth mount, meaning it swiveled in two directions: altitude (vertical) and azimuth (horizontal).  Dobsonian type telescopes also work this way. Mount selecting can be crucial to overall user happiness; a wobbly, linguini mount will shutter with the smallest gust of wind and make finding things and keeping them centered nearly impossible.  Equatorial mounts are more advanced and motorized ones will track the sky as the Earth rotates beneath you.  Mount locking clamps for both axes and fine tuners for centering objects are invaluable although certainly not mandatory; many telescopes rely solely on manual “nudge” power to do final centering.  I frequently used this method for pointing the Flandreau Observatories’ 16-inch telescope; the slow motion controls were simply too slow.  With the clamps only lightly applied and at low magnification, I would use my entire body to gently “jerk” the scope into position… a very low tech but effective maneuver!    

   A 4 or 6″ Newtonian reflector is also a good first telescope for a beginner that will give years of enjoyment. Compact and versitile,  these are good for both planetary and deep sky observing and generally run 200$-300$ for a good Dobsonian mounted scope. 

   As far as finders are concerned, good “x1″ Telrad style finders can’t be beat… and they can be installed on any scope when you upgrade.  They are permanent “must have” fixtures on many telescopes.   

Most dihard obseverers I know still have and use these first telescopes, a testament to their versatility.  With any luck and dark skies, they can provide a life times worth of enjoyment!                  

  

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  1. Jessie says:

    Jessie…

    I?ll admit it. i have been to your blog SIX times since your last post looking for a new post?….

  2. [...] cameras, one of the biggest decisions you’ll make in your life-time is the purchasing of a first telescope. True, the technology changes so quickly, today’s cutting edge instrument is tomorrow’s old [...]

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