Getting started in astronomy can be a fun and rewarding experience, but it can also be overwhelming. Here are some steps to help you begin:
Learn the basics: Start by familiarizing yourself with basic astronomical concepts and terminology. You can find many beginner-friendly resources online, such as introductory videos or articles
Here are some basic astronomical concepts that are essential to understanding the universe:
Stars: A star is a massive, luminous sphere of plasma held together by its own gravity. Stars emit light and heat, and are the building blocks of galaxies.
Planets: A planet is a celestial body that orbits a star, is not a star itself, and has cleared its orbit of other debris. There are eight planets in our solar system, including Earth, and countless more in the universe.
Galaxies: A galaxy is a large group of stars, dust, and gas held together by gravity. Our Milky Way galaxy is just one of billions of galaxies in the universe.
Black Holes: A black hole is a region of space with a gravitational pull so strong that nothing, not even light, can escape it. They form when a massive star collapses in on itself.
Nebulae: A nebula is a cloud of gas and dust in space. They are often the birthplaces of stars and can be seen as colorful clouds in the night sky.
Constellations: A constellation is a group of stars that forms a recognizable pattern in the sky. People have been naming and identifying constellations for thousands of years.
The Universe: The universe is everything that exists, including all matter, energy, and space. It is believed to be around 13.8 billion years old and is constantly expanding.
These are just a few of the basic concepts of astronomy, but there is much more to learn and explore!
Get a telescope: You don’t necessarily need a telescope to enjoy astronomy, but it can greatly enhance your experience. There are many types of telescopes available, so it’s important to do some research and find one that fits your needs and budget.
Telescopes come in different types and sizes, and each one is designed for different purposes and can observe different objects in space. Here are some general guidelines for choosing a telescope based on the range of space you want to observe:
Planets and Moon: If you are interested in observing the planets and the Moon, you will want a telescope that has good magnification capabilities. A refracting telescope or a Schmidt-Cassegrain telescope (SCT) with an aperture of at least 60mm will work well for this purpose.
Deep Sky Objects: If you are interested in observing deep sky objects such as galaxies, nebulas, and star clusters, you will want a telescope with a larger aperture to gather more light. A reflector telescope or a SCT with an aperture of at least 100mm is recommended for observing deep sky objects.
Wide-field viewing: If you want to observe a large field of view, such as the Milky Way or a comet, a telescope with a shorter focal length and wider aperture is recommended. A refractor or a SCT with a focal length of 400-500mm and an aperture of 80-100mm will work well for wide-field viewing.
Astrophotography: If you want to capture images of celestial objects, you will need a telescope with a sturdy mount and good tracking capabilities. A SCT or a refractor with an aperture of at least 80mm is recommended for astrophotography.
It’s important to keep in mind that there are many factors to consider when choosing a telescope, such as budget, portability, and level of experience. It’s always a good idea to do some research and seek advice from other amateur astronomers or astronomy clubs before making a purchase.
In this guide you’ll learn how to choose a telescope, including how to choose a telescope for stargazing and some tips on how to choose a telescope for a child. A telescope makes a wonderful gift for someone who has an interest in the night sky. Even a majority of the smallest inexpensive telescopes are capable of revealing the rings of Saturn, the cloud belts of Jupiter, hundreds of star clusters, and even distant galaxies. With a medium or large telescope, amateur astronomers rarely see everything there is to see with a telescope, even after years of observing. Astronomy is truly an interest that can last a lifetime, especially if you know how to pick a telescope that will continue to be used as the hobbyist picks up more skills.
Since any telescope, even a small one, can produce any given magnification with the right telescope eyepiece, magnification is not a useful way to rate a telescope. Therefore, the size of the lens or mirror (the heart of the telescope) is used as a general way to measure telescope potential. This is usually part of the telescope’s model description.
Size of the Lens or Mirror
The larger the telescope lens or telescope mirror, the fainter the objects a telescope will reveal (the more objects that will be visible), and the greater the telescope magnification it can use and still produce a good image. For example, at 120x, a ten-inch telescope will reveal hundreds of objects not visible in a three-inch telescope. In addition, at 120x, the 10-inch telescope will produce images that are brighter and sharper than the 3-inch telescope.
Large vs. Small Telescopes
For amateur astronomers, a small telescope generally refers to a telescope of 4 inches or less. A medium telescope generally means a telescope of five to eight inches and a large telescope usually means anything over ten inches in size. However, this is a very general way to look at a telescope. Optical quality and special features may allow a small telescope to outperform a larger telescope for some types of observing.
Is Larger Always Better?
When it comes to telescope sizes, not always. Large telescopes do translate into more objects seen and better images, but they are also more expensive and also less portable. Many astronomers choose smaller telescopes because they need to transport them to locations where the sky is darker and more stars are visible. Even if observing will be done at home in the backyard, portability is still a factor. When a telescope becomes a chore to move and set up because of its size, it’s doomed to collect dust in the closet. If you are buying a telescope for a new astronomer, especially a child, it also makes sense to start with a telescope that is suitable to their size, age, and interest.
What to Look For
You need a starfinder or planisphere. It will help you locate the most common things to look at in the sky. A great tool for the beginner is a finderscope, a piece of equipment that will help you find various objects in the cosmos. It also provides interesting facts and information about astronomical phenomena. It’s a great telescope accessory to get started in stargazing.
Proper Magnification
You probably don’t need as much as you think. Few astronomical objects require more than 350x magnification and most observing is done at less than 200x, even with a large telescope. It is essential to understand that as magnification goes up, telescope image quality goes down and that it goes down much quicker in a small telescope.
500x Magnification with Small Telescopes
Yes, you can get 500x or 600x magnification, even in a small telescope, if you use the right telescope eyepieces. However, at such extreme magnification, the images produced will be useless. Worse yet, especially for the beginner astronomer, as magnification goes up, the ease of astronomical telescope use quickly goes down. At 500x, a small telescope is impossible to use, despite what it might say on the box about magnification.
Minimum Magnification With a Good Image
That depends partly on Mother Nature. On nights when the sky is clear and stable, you can use higher magnifications than on nights when the sky is hazy or unsettled. Assuming good conditions, a basic rule of thumb is 30-50x of magnification for every inch of a telescope as a maximum. Thus, the top useable magnification for a 2.4 inch (60mm) will be in the neighborhood of 120x on nights when the sky allows it. This is still more than enough to see the rings of Saturn, cloud belts on Jupiter, and many star clusters and nebulae. Magnifications above this in a 2.4-inch telescope, even if you have the telescope eyepieces to obtain it, will produce images of low quality. Above 350-400x, even large telescopes have trouble seeing through the atmosphere above us.
Determining Magnification with the Eyepiece
Telescope eyepieces are marked with their focal length in millimeters, not magnification. To calculate the magnification you will get with any telescope eyepiece, divide the focal length of the telescope eyepiece into the focal length of the telescope. A telescope eyepiece with a focal length of 25 mm when used in a telescope with a 1,000 mm focal length, therefore, produces a magnification of 40x.
How to Choose a Telescope By Type
Reflector Telescope
Newtonian Reflector Telescope
A reflector telescope uses a large mirror at the bottom of the telescope to focus light rays on a smaller mirror near the opening which then reflects the light into an eyepiece located at the top of the telescope. The Newtonian reflector is the oldest reflector design in use and still the most popular reflector telescope.
Advantages
Reflector telescopes cost less to produce than other types and offer the most telescope for the money. Reflector telescopes produce good images and are favored by astronomers who need the largest possible telescope to find distant, faint objects beyond our solar system (deep-sky objects). If you are thinking of giving a telescope that will allow room to grow in astronomy, a medium (four and a half inches or larger) reflector telescope is the least expensive way to go.
Disadvantage
Reflector telescopes are more fragile than other types of telescopes and need periodic readjustment of the telescope mirrors (a process called collimation) and, because they are open on the top (Newtonian reflector), the mirrors are exposed to dust and dirt and therefore need periodic cleaning. The reflector telescope is by no means fragile, but it’s the least childproof telescope design. The telescope eyepiece, located at the top of the telescope, may also be more difficult for children to reach.
Schmidt-Newtonian Telescopes
A Schmidt-Newtonian reflector telescope is a catadioptric telescope (a telescope that uses both lens and mirrors). The SN telescope uses a special plate at the top of the tube to correct the image before it reaches the primary mirror at the bottom of the tube. This makes the SN reflector telescope shorter than a standard Newtonian reflector with no loss of performance.
Advantages
The Schmidt-Newtonian telescope is a shorter overall reflector than a Newtonian reflector which makes it more portable and easier to use. Because of the corrector plate (lens) at the top of the tube, the optics in a Schmidt-Newtonian telescope are also better protected against dirt and dust than a Newtonian reflector.
Disadvantages
Unlike the Newtonian reflector, the corrector plate at the top of the SN telescope can collect dew, and like the Newtonian reflector, the SN reflector still needs periodic collimation of the mirrors. These, however, are minor concerns in an otherwise excellent telescope design.
Refractor Telescope
Refractor telescopes use lenses (not mirrors) at the top of the telescope to focus light rays into an eyepiece at the bottom of the telescope. It’s the same design used in binoculars and most spotting scopes (daytime telescopes).
Advantages
Refractor telescopes are virtually maintenance-free since the telescope tube is closed (not open as in a Newtonian reflector) and there is no telescope mirror to adjust. The refractor telescope is the most rugged telescope design and in the most expensive versions, a refractor will produce the brightest and sharpest image per inch of a telescope. The refractor telescope is a good choice for children, not only because it’s rugged, but also because the telescope eyepiece is located at the bottom of the telescope where it’s easier for small people to reach. Refractor telescopes are also easier to use as a daytime telescope (with an image erector) than reflector telescopes.
Disadvantages
The refractor telescope is the most expensive telescope per inch of telescope size; beyond three inches, the refractor goes up very quickly in price. If you buy a beginner a small refractor, be advised that the beginner may quickly outgrow it if they stay with astronomy for long.
Schmidt Cassegrain (SCT) Telescopes
A Schmidt Cassegrain is a catadioptric telescope (a telescope with lenses and mirrors) that uses a combination of mirrors to squeeze an optically very long telescope into a short tube. A Schmidt-Cassegrain telescope has features of both a refractor (eyepiece at the bottom) and reflector (uses lenses) but is considerably shorter and more compact than either one. The Schmidt Cassegrain telescope is very similar to the Maksutov-Cassegrain below, but it uses a thinner, less complex corrector plate at the top of the telescope making it more affordable and lighter in weight when used in large telescopes.
Advantages
A Schmidt Cassegrain telescope offers some of the advantages of a refractor telescope – durability and less maintenance – but at a lower price. The main advantage of a Schmidt Cassegrain telescope is portability; even a 5-inch Schmidt Cassegrain is small enough to carry on the front seat of your car. A Schmidt Cassegrain is regarded as the best all-purpose telescope for an astronomer who will be mixing visual observing with astrophotography.
Disadvantages
A Schmidt Cassegrain telescope has a mirror in the front that partially obstructs the field of view and causes some light to be lost. For this reason, you may notice a slight darkening at the center of the field of view, though the effect on performance is negligible. Schmidt Cassegrain telescopes do not produce images quite as bright as the best reflector telescopes or an image quite as sharp as the best refractor telescopes, but its versatility is better than either.
Maksutov-Cassegrain Telescopes
Maksutov-Cassegrain telescopes, like the Schmidt-Cassegrain telescopes, are catadioptric telescopes (a telescope with lenses and mirrors). The difference between the Schmidt Cassegrain and the Maksutov-Cassegrain is in the shape and size of the corrector plate (lens) at the top of the telescope. The Maksutov-Cassegrain uses a heavier, more complex corrector plate.
Advantages
The Maksutov-Cassegrain telescope corrector plate allows for very fine correction of its optics. The Mak is a telescope capable of superb image quality, second only to the finest refractor. The Maksutov-Cassegrain is also a great design for smaller telescopes and is very popular for spotting scopes.
Disadvantages
The corrector plate on a Mak is heavier and more costly to produce. Maksutov-Cassegrain larger than 7 inches are, therefore, rare.
Dobsonian Telescopes
A Dobsonian telescope is more of a type of mount than a type of telescope. A Dobsonian telescope is a large Newtonian reflector (six inches or larger) mounted on a simple box-like alt-az mount (see mounts below).
Advantages
A Dobsonian telescope is the essence of simplicity and a perfect choice for the astronomer who shuns hi-tech gadgetry and electronics. The “Dob” is the telescope for the deep-sky purist who wants to see the faintest objects at millions of light-years beyond our solar system. The secret of the Dobsonian telescope is in its size – it’s the largest telescope for the money you can buy. A huge ten-inch or even twelve-inch Dobsonian telescope will cost less than a fancy computerized telescope half its size and will easily take you to places in the universe no smaller telescope can go. Even an advanced amateur will not outgrow a ten-inch Dobsonian in his or her lifetime.
Disadvantages
Dobsonian telescopes above ten inches in size are a problem to transport – a disassembled ten-inch Dobsonian telescope will still squeeze into a hatchback with all seats folded down and no passengers, but a twelve-inch Dobsonian will not. Because a Dobsonian mount is all manual, it requires constant readjusting (though easily done with practice) to keep an object in the telescope eyepiece. For the same reason, it’s limited for use as an astrophotography telescope.
Telescope Mounts
A telescope is only as useful as its mount – the higher the magnification, the truer this becomes. A telescope mount not only steadies the telescope, but it also allows the telescope to follow stars and planets as they move across the night sky. When seen in the eyepiece of a telescope, stars and planets move slowly across the field of view in the eyepiece and disappear (because the telescope magnifies the earth’s rotation, not because the stars move). To keep the object centered in the eyepiece, the telescope must be moved constantly. This is done in several ways, depending on the telescope mount.
Alt-AZ Mounts
An Alt-AZ telescope mount requires you to move the telescope to the object you wish to find. You then move the telescope in two directions (up-down and right-left) to keep the object centered in the eyepiece as it moves. This is because stars move across the sky in a gentle arc or curve, but an Alt-AZ telescope mount only allows the telescope to be moved in a straight line.
Advantages
Alt-AZ telescope mounts, because of their simplicity, are the least expensive telescope mounts. They are uncomplicated and rugged and the least likely to be damaged by over-eager children.
Disadvantages
Because a star or planet follows a gentle curve across the night sky instead of a straight line, a telescope on an Alt-AZ mount must be adjusted both in an up-down as well as a right-left direction to keep a star or planet in the eyepiece. This is not much of a problem at low magnifications, but above 75x or so, an Alt-AZ mount can be frustrating for a beginner to use.
German Equatorial Mount
An equatorial telescope mount requires you to move the telescope to the object you wish to find, just as with an Alt-AZ mount. To keep an object centered in the eyepiece, however, requires only a simple nudge of the telescope because the equatorial mount moves the telescope in the same gentle curve that stars follow across the sky. You can spot an equatorial telescope mount easily because it looks like a couple of pipes laid crosswise against each other. One of these “pipes” often has a set of counterweights to balance the telescope as it moves.
Advantages
An equatorial telescope mount moves a telescope across the sky in the same curved path that stars and planets move. To follow a star or planet, then, requires only a simple nudge of the telescope rather than two adjustments as needed in an Alt-AZ mount. This makes following objects in the sky much easier and makes higher magnifications more practical. Many beginner telescopes are now available with an equatorial telescope mount.
Disadvantages
To use the equatorial mount effectively requires that it first be aligned with true north (near Polaris or the North Star). Children may need assistance for this. In larger telescopes, equatorial mounts become heavy and unwieldy and may require some disassembly when moving the telescope.
Manual GOTO Mount
A manual GOTO telescope mount is an Alt-AZ mount with a computer attached to one arm. A manual GOTO telescope mount requires you to move the telescope manually to find an object, just as in a standard Alt-AZ mount, but the computer gives you directions to find your object and tells you when you have found it. Once found, you still have to move the telescope to keep the object in the eyepiece (with the computer giving directions).
Advantages
The manual GOTO telescope mount is an inexpensive way to help a beginner find an object in the night sky. it’s a good choice for those who wish to keep things simple but still need some help navigating among the stars.
Disadvantages
A manual GOTO telescope mount still requires you to move the telescope yourself and is subject to all the other limitations of an Alt-AZ mount – best used at lower magnifications and for brighter objects.
Motorized Mounts
A motorized telescope mount is a mount that requires you to move the telescope to the object you wish to see but then keeps it in the eyepiece for you by moving the telescope with a motor. In other words, once an object is found, no adjustment is needed to keep it in the eyepiece. A motorized telescope mount can be any type of mount – Alt-AZ, fork, or equatorial – that has an attached motor. The motor moves the telescope at the same rate of speed as objects that move across the night sky.
Advantages
For visual observing, a motorized telescope mount makes it much easier to use high magnification – the observer spends more time viewing and less time moving the telescope. This is also the best telescope mount to use when sharing the telescope with others – no need to adjust the telescope after each person has had their turn. For serious astrophotography, a quality motorized mount is a must, with a motorized equatorial preferred.
Disadvantages
To be effective, a motorized telescope mount must be carefully aligned first. The procedure will vary with the type of motorized mount, and periodic corrections will be needed to keep things in alignment. The best motorized equatorial mounts can also be very expensive and cost as much or more than the telescope.
GOTO (Computerized) Motorized Mount
A GOTO computerized telescope mount is a motorized mount that finds the object for you using a computer (usually with a handheld controller) and then keeps the object in the eyepiece for you.
Advantages
Astronomy changed in a big way when computers were added to a telescope. To find objects in the night sky without a GOTO mount requires use and expertise with a star map, knowledge of the constellations, and experience (one reason so many beginners abandon astronomy as a hobby). Now anyone with a GOTO telescope mount can do instantly what used to require many nights under the stars to learn. Yes, some beginners will never bother to learn the night sky because of this technology, but for those who develop a real passion for astronomy and want to learn their way around the stars, GOTO technology is a great teacher.
Disadvantages
This is not a technology for those who have an aversion to bells and whistles or computers. There is also a matter of expectations to consider. On small telescopes, the computer database in the mount may easily exceed the capability of the telescope. In other words, just because the computer is pointing the telescope at an object is no guarantee that the image in the eyepiece will be impressive or even visible, especially on nights of poor sky conditions. No computer can turn a small telescope into a large telescope.
Fork and GPS Mounts
Fork Mounts
A fork mount is a type of Alt-AZ telescope mount, usually motorized (read “What is a motorized mount?” below). The fork mount is widely used on Schmidt Cassegrain and Maksutov-Cassegrain telescopes. These are highly portable telescope mounts that can actually be used with or without a tripod if placed on a flat, level surface.
GPS Mounts
A GPS (Global Positioning System) is a navigational system that uses radio signals from satellites to locate your position anywhere on earth. On a telescope mount, it’s used in conjunction with motorized GOTO telescope mounts to inform the computer of the date, time, latitude, and longitude. For most GOTO telescope mounts without GPS, this information must be inputted manually by the observer.
Spotting Telescope (a.k.a. Spotting Scope)
A spotting scope is a small telescope designed for daytime observing of birds, wildlife, boats, airplanes, and any application where high magnification is needed. Optically speaking, most spotting telescopes are refractors, but several excellent spotting scopes are Maksutovs. Many astronomical objects – the rings of Saturn, Jupiter, star clusters, nebulae – are within the magnification range of a 20-60x zoom spotting scope.
Advantages
The biggest advantage of using a spotting scope for astronomy is that it can also be used for daytime observing. If you are uncertain that the person on your gift list will sustain an interest in astronomy – particularly children – a spotting scope is a much more practical gift than a standard astronomy telescope. It’s much easier to use a spotting scope for astronomy than it’s to use a standard astronomy telescope by day.
Disadvantages
A spotting scope for astronomy is limited by its size – most are 80mm or less – and also by its magnification – most spotting scopes go no higher than 60x. However, a few spotting telescope models use interchangeable telescope eyepieces which makes them more practical to use as astronomy telescopes. (see next question).
Summing It Up
Now that we’ve covered how to choose a telescope, you should be prepared to pick one out depending on your astronomical interests. Whether you’re shopping for yourself or looking for the perfect gift for an aspiring stargazer, you can trust OpticsPlanet to meet all of your needs. Shop our Astronomy Store today!
One of the earliest activities we engaged in when we first got into astronomy is the same one we like to show our children just as soon as their excitement about the night sky begins to surface. That is the fun of finding constellations. But finding constellations and using them to navigate the sky is a discipline that goes back virtually to the dawn of man. In fact, we have cave pictures to show that the more primitive of human societies could “see pictures” in the sky and ascribe to their importance.
Constellations also have been important in culture and navigation long before we had sophisticated systems of navigation. Early explorers, particularly by sea, relied exclusively on the night sky to help them find their way to their destination. In fact, when “Columbus sailed the ocean blue in 1492″ and “discovered” America, he could not have done it without astronomy and the help of navigation of the cosmos, much of which is made possible because of the important constellations.
When learning to find the great constellations in the sky, we use the “find one, you found them all” system. That is because the easiest constellation to find will guide us to the rest of them. That constellation is The Big Dipper. Look to the northern sky on a clear night and widen your field of vision from just focusing on one star and it will pretty much jump out at you. In will look like a big kitchen pot or ladle, right side up in the fall, upside down in the spring.
When you have the big dipper under control, you can pretty easily find the North Star. This is the star that those ancient sailors depended on the most to find their way to land. Start with the far edge of the bowl of the Big Dipper, the side that is opposite the handle. There are two stars that make up that side of the bowl. So start at the bottom of the pot and mentally draw a line to the top star of the bowl. These two stars are “pointing” to the North Star. Just keep following that line, curving a bit with the sky and the bright star that you come to is the North Star. You can impress your friends or family if you know the scientific name for this star is Polaris.
The North Star can then take you to The Little Dipper. The key here is that Polaris is the tip of the handle of The Little Dipper and the bowl hangs down from the handle like it was hanging up in the kitchen. Be patient with this one as the stars that make up The Little Dipper are dimmer than The Big Dipper. But it pretty cool once you find it.
These are the obvious starting places but from The Little Dipper you can find the constellation known as “The Swan” or Cygnus. Just use the same system you used to find The North Star but continue drawing that line that started in those pointer stars in the bowl of The Big Dipper. Go about half as far as you went to find Polaris and you are there. You will see a trapezoid of stars about as big as The Big Dipper. This trapezoid forms the tail of The Swan.
That line that we are drawing from the pointer stars is our roadmap to another well known constellation which is Cassiopeia. If you use that line and imagine you are directly under the two pointer stars, you will se a big “W” just off to the left of the line. This is the constellation Cassiopeia, the wife of the king of Egypt, Cepheus, in Greek mythology. There are so many more wonderful constellations to find and a good star map can continue your search.
Like Cassiopeia, all of the constellations have wonderful stories and myths related to Greek culture. It is just as fun to find the star clusters themselves as it is to enjoy the rich culture related to that constellation. For all of the signs of the zodiac, for example, there is a related constellation in the sky. So whether you are serious about astrology or not, its fun to find the constellation that relates to your “sign” (or that of your children) and be able to see how the ancients related to these pictures in the sky.
The number on the eyepiece is the focal length of the eyepiece. It is not the magnification of the eyepiece.
Eyepiece Magnification
The magnification of any telescope eyepiece used with your telescope will be the focal length of the telescope (consult your manual) divided by the focal length of the eyepiece. A telescope with a focal length of 1200mm will yield a magnification of 60x when you insert a 20mm eyepiece into the focuser. A telescope with a focal length of only 600 mm, however, will yield only 30x when used with the same 20mm eyepiece.
Telescope Eyepieces for Beginners
ALWAYS start observing with the lowest magnification eyepiece available until you become skilled in the use of your telescope. This will be the eyepiece marked with the BIG number (longer focal length), not one of the smaller numbers. Again, the number you see on the eyepiece is the focal length, not the magnification.
Low vs High Magnification
A low magnification eyepiece has a wider field of view (the amount of sky you see when looking through the eyepiece) than a high magnification telescope eyepieces. The low-magnification eyepiece therefore makes it easier to “capture” an object you are trying to find in your telescope. Your lowest magnification eyepiece will also give you the sharpest image as well as the brightest image.
Once you have located an object with your low magnification eyepiece, move the telescope so the object is as close to the center of the telescope field of view as possible. Replace the low magnification eyepiece with one of higher magnification. If the object is not visible after you have changed to the high magnification eyepiece, go back to the low magnification eyepiece and start again.
Increasing Magnification
A basic law of optics states that as magnification increases, image brightness decreases. In fact, if you increase magnification enough, an object will become too faint to see. This happens sooner in a small telescope than large telescopes.
Barlow Lens for Telescopes
A Barlow lens is a lens that you use with your eyepiece. A Barlow lens will double (2x Barlow) or even triple (3x Barlow) the magnification of any eyepiece that you attach to it. To use a Barlow lens, remove the eyepiece from the focuser, insert the Barlow and then insert the eyepiece into the Barlow. Remember, though, that a Barlow is best used with low magnification (long focal length) eyepieces. When used with high magnification eyepieces, it may produce more magnification than your telescope can use.
Disappearing Objects in the Field of View
The telescope is not only magnifying the object you are observing in the sky, it is also magnifying the earth’s rotation! The more magnification you use in your telescope, the quicker an object drifts out of the field of view. Manual telescope mounts will require you to continually “recapture” the object by moving your telescope slightly. Motorized mounts move the telescope for you and keep the object in the eyepiece.
Telescope Magnification Use
Use only enough magnification to provide a useable image. When you reach a point where the image has become so blurred as to lose useful detail, you are using too much magnification! At what point this happens depends on the object you are observing, the seeing conditions (atmospheric clarity and stability) and the size of your telescope (you can get more magnification out of a large telescope before images begin to blur).
Observing Expectations from your Telescope
You will be able to see many of the same things you see in magazines and books, but the images produced in your telescope will smaller and less spectacular. The images in magazines and books are produced by large observatory telescopes that take long exposure photographs with special cameras. It simply isn’t realistic to expect a small amateur telescope to produce visual images of the same quality.
Telescope Observing Benefits
There is so much more to that little smudge of light you see in your eyepiece than meets the eye! Spend a little time and effort to learn about the things you see in your telescope and you will appreciate them much more. Remember, that little smudge of light may actually contain billions of stars and its light may have taken many millions of years to reach your telescope.
Besides, much of the thrill in amateur astronomy is seeing the glories of the night sky with your own two eyes. The difference between seeing a picture of Saturn in a book and seeing Saturn in your backyard through a telescope is a lot like the difference between seeing pictures of Alaska in a book and going to Alaska to see it for yourself.
Amateur Astronomy
Amateur astronomy is also about the challenge of finding faint, hard to see objects. This often frustrates the beginner (hence the popularity of computer GOTO telescopes) but it also keeps the die-hard enthusiasts out late into the night. Even if you use a GOTO telescope, you owe it to yourself to learn how to navigate by means of a star map . There are no words to describe the thrill of finally seeing a faint galaxy or nebula after several hours or even nights of looking for it.
Lastly, there is a great amount of satisfaction that comes with knowing your way around the night sky. At a time when many of us feel alienated from the natural world, astronomy provides a way to reconnect to the universe around us.
When viewing distant objects through the use of a telescope, the most important part of that telescope is called the objective. The objective is that component of the telescope that has the ability of gathering the light that is available. Obviously, the larger the objective the greater is the capacity of the telescope to gather light which in turn allows the viewed image to be better visualized.
In addition, there are two types of telescopes. One type of telescope is called the refractor telescope and the other is known as the reflecting telescope. The difference between these two telescopes is how the light is captured.
The refracting telescope obtains the light through its objective that is made out of glass. Basically, in this type of telescope, the glass lens is situated towards the front of the telescope. As the light is captured by the objective, it is then refracted or deflected through a lens which allows for the viewed image to be magnified. Examples of this type of telescopic equipment include scopes that are used on rifles, binoculars and spyglasses.
A reflecting telescope uses a mirror as its objective. This mirror is located towards the distal end of the telescope. In addition, the mirror has a concave shape. The curvature of the mirror allows for the midpoint of the mirror to be the focal point for all of the light that strikes each part of the surface of the bowl-like mirror. This reflection is then captured by the lens to view the item of interest.
There are several advantages to the use of a reflecting telescope. The major advantage is that distortion of what is being viewed is minimal. This is because, through the use of the mirror, the wavelengths are all reflected consistently. This advantage also leads to the reflecting telescope being less expensive than the refracting telescope.
In addition, through the use of the mirror as the objective, the support for this mirror can be all along the posterior portion of the telescope. This allows for the housing to be very large which will accommodate a larger mirror. Larger mirrors mean more light which results in increased visibility.
Disadvantages
However, as with anything else, there are a few disadvantages in the use of a reflecting telescope. One of those disadvantages is size. This is due to the fact that these types of telescopes can accommodate larger mirrors. This results in the telescope itself being larger which may prove to be an issue when storing or relocating the reflecting telescope.
In addition, because of the use of mirrors, there may need to be occasional adjustments made so that optimum light alignment is maintained.
The World Of Refractor Telescopes
Refractor telescopes are some of the oldest telescopes available, utilized at around the beginning of the 15th century and still around today the refractor telescope is quite possibly one of the oldest telescopes in use today. Made up of concave lenses that allow the light to be refracted and images to appear bright and larger than looking at it with the normal eye the refractor telescope can greatly aid in seeing stars, planets and moons.
These telescopes are made up of convex lenses and an eyepiece lens similar to binoculars, these refractors gather light and bend it in order to view objects at a distance, which is particularly useful when looking at stars and the night sky Refractor telescopes may seem complicated and are made up of lenses that are concave and refract the light.
The telescope come in a variety of versions; the Galilean telescope which is named after its creator was one of the first versions and was improved upon by Johannes Kepler with the Keplerian Telescope, which is a refractor telescope that utilized a convex eyepiece as opposed to a concave of the Galilean model. The decades and centuries since have observed newer inventions and different lenses, with the achromatic refractors invented in the mid 16th century and later with apochromatic refractors.
Pros and Cons of Refractor Telescopes
Telescope for Kids & Adults – 70mm Aperture 500mm AZ Mount Fully Multi-Coated Optics Astronomical refracting Portable Telescopes, with Tripod Phone Adapter, Carrying Bag, Remote Control
I stated previously that refractor telescopes have been around a long time and with that comes a definite plus since there is a definitive ability to know what the pros and cons of the telescope. These telescopes have obviously come a long was since the 15th century yet the technology has increased to a point in which the refractors have improved yet the size of refractor telescopes pose a problem in the fact that the larger the refractor lens the more chance that it can have defects or begin to sag.
While technology continues to grow and there is no telling where refractor lenses in telescopes will go to in the future one thing for sure is that refractor telescopes have been around for centuries and thus show no decline in their use by many of astronomers. So no matter what telescope you choose to utilize to view the universe or neighborhood, you can not dismiss the value of the refractor telescope and the impact that its utilization has had on astronomy and the search of the skies.
We have a special feeling toward the other planets that circle our sun. Maybe it’s all the science fiction stories about visiting the moon, Mars and other planets. But we love to think about those planets that make up what we call “the solar system.” that do what our planet does but do it very differently indeed.
The planets of our solar system have taken on personalities and mythical appeal in our literature and arts. It is easy to find artists who render their vision of the planets that make up our society of planets near our sun. The names of the planets, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune are all from our cultural past being gods from Greek and Roman mythology. But the solar system is not just made up of these planets. The solar system is a very busy place indeed.
In 2006, there was quite a bit of controversy as scholars and astronomers agreed to downgrade Pluto and remove its status as a planet. So you have to wonder, what is it that makes something a planet and what happened to Pluto? It didn’t just go away so it must still be out there. A planet, by scientific definition is any object in orbit around a sun, that has formed into some kind of round object is a planet as long as it has cleared away any other orbiting items around it. By cleared away, that doesn’t mean it has destroyed all space debris etc. For example, our planet has not “cleared away” the moon but it has captured it into its own orbit so we classify as a planet. That’s a relief huh?
There are many objects floating around in our solar system other than the planets we know of. It’s an interesting piece of trivia that in addition to the planets there are 165 moons orbiting around those nine planets. Some of those moons are so advanced that some scientists have suspected that they might have supported life at some point.
In addition to the regular planets and moons, there are dwarf planets, asteroid belts and routine visits by comets that create a lot of traffic in our cosmic corner of the universe. The two known dwarf planets that exist on the outer rim of our solar system are Eries and Ceres. So when Pluto’s status was changed to be removed from the list of planets, it simply joined those two bodies as dwarf planets but still a solid citizen of the community of celestial bodies around our sun.
In addition to these larger bodies, there is an asteroid belt that exists between Mars and Jupiter that most of the asteroids that we see in our night sky come from. There is another belt of large objects further out called the Kuiper belt as well as a “bubble” in space called a heliopause and there is a suspected additional belt outside the known solar system called the Oort belt that we think is the origin of a lot of large asteroids and comets that frequent our solar system and come to orbit our sun.
As fascinating as these many celestial bodies who are our neighbors in space is the origin of our solar system. We have to break it down to simple terms to understand the terms but we know that the early history of the solar system and the universe was one of great bodies of gas and clouds of matter eventually cooling and heating, exploding and spinning off stars and other massive space giants that became more stars, galaxies and solar systems. It was from this erratic activity that our sun separated from the gasses and carried with it the material that became our solar system. The gravity of the sun captured sufficient matter that it began to go through the process of forming, cooling, exploding and separating. This is what happened as the planets all went through he same process eventually establishing stable orbits and small objects falling into orbit around them.
When you think of how powerful and out of control this process is, it’s amazing to step back and see the beauty of the organization of our solar system today. The more detail you learn about the history of our solar system, the more you will enjoy your explorations of the planets with your telescope. That that discovery is part of the fun of astronomy.
If you are a serious astronomy fanatic like a lot of us are, you can probably remember that one event in childhood that started you along this exciting hobby. It might have been that first time you looked through a telescope. But for many of us, it was that first time we saw a rain of fire from the sky that we eventually came to know as a meteoroid shower.
A view of a Meteor Shower and the Milky Way with a pine trees forest silhouette in the foreground. Night sky nature summer landscape. Perseid Meteor Shower observation.
At the time when you see the first one, it’s easy to remember the movie “war of the worlds” or some other fantastic image of aliens entering our atmosphere in droves to take over the planet. But with some guidance and explanation of what was going on, we eventually learned that these showers were not at all threatening or any kind of invasion. For the most part meteoroid showers are harmless, part of nature and very fun to watch.
So what are these strange lights in the sky? Are they aliens invading from Mars? Are the comets coming to start the next ice age? Or perhaps asteroids burning up as they enter the earths atmosphere. The answer to the above questions is no to the first and “yes and no” to the other two.
A meteoroid is actually a small piece of space rubble, usually dust or small rocks that come from either a comet or the break up of an asteroid in space and that eventually plummets toward the earth. We say “toward the earth” because the lights you see are the friction of the atmosphere burning up those small space tidbits and creating a spectacular show for all of us as they do so. A particularly exciting moment to witness is when a meteoroid breaks up or explodes on entry. A meteoroid that explodes is called bolides.
There are some interesting details about the life of a meteoroid that make the viewing of shooting stars even more fun. To be seen, a meteoroid only needs to weigh as little as a millionth of a gram. But the thing that makes them so spectacular to see is the tremendous speeds they reach as they enter the atmosphere. Before burning up, a meteoroid will reach between 11 and 74 kilometers per second which is 100 times faster than a speeding bullet.
We tend to think of seeing a shooting star as a freak event and we associate it with superstition (hence, wish on a lucky star). But there are actually thousands of them every year so it really isn’t that rare to see one. In fact, scientists tell us that over 200,000 tons of space matter enters the atmosphere each year and burns up on entry.
Comets are a big source of meteoroids because of the nature of those long tails. A large amount of dust, ice and other space debris gets caught up in a comet’s tail as it moves toward the sun. Then as the comet moves away from the sun in its orbit, tons of this matter is thrown off into space to disperse. As the Earth moves in its routine orbit around the sun, it often crosses through clouds of this discarded matter which becomes one of those “meteor showers” that are so popular for viewing.
These showers of shooting stars are pretty easy for astronomers to predict so you can get into position to see the excitement at just the right time of night and be looking at the right area of the night sky. Usually the astronomy magazine or site will give you a general time and location to be ready to look when the meteoroids start to fall.
Meteor Shower and the Milky Way with old ruin on foreground
Now keep in mind, this is a phenomenon of nature, so it may not observe the time table exactly. Also note that there is a notation system for where the meteoroid shower will occur based on what constellation is its backdrop. The section of the sky to focus on for the show is called the “radiant” because that is where the entering meteoroids begin to glow or radiate. The radiant is named for the constellation it is nearest too. So if the meteor shower is going to occur in the constellation of Leo, then its radiant will be called Leonid. This will help you decipher the listing of asteroid showers in the publications.
The one thing we love the most in the world of astronomy is a good mystery. And if there was ever a mysterious and yet very powerful force of nature that we witness in the night skies, it is the coming of the mighty comet.
A bright comet with large dust and gas trails as the comets orbit brings it close to the Sun. Illustration.
The arrival of a comet within view of Earth is an event of international importance. Witness the huge media attention that the Haley or Hale-Bopp have had when they have come within view The sight of these amazing space objects is simultaneously frightening and awe inspiring.
Above all, it is during these comet viewings that the astronomer comes out in all of us. But what is a comet? Where did it come from? And how does it get that magnificent tail?
We should never confuse comets with asteroids. Asteroids are small space rocks that come from an asteroid belt between Mars and Jupiter. While still quite stunning to see, they pale in comparison to the arrival of a comet. Asteroids also have received considerable study by the scientific community.
meteorite from outer space, falling toward planet Earth, dramatic science fiction scene
Not as much is known about comets. As a rule, comets are considerably larger than asteroids. The composition of a comet is a mixture of nebulous, gasses, ice, dust and space debris. One scientist called the composition of a comet as similar to a “dirty snowball” because the composition is so diverse and changeable. The center or nucleus of a comet is usually quiet solid but the “snowball” materials often create a “cloud” around that nucleus that can become quite large and that extends at great lengths behind the comet as it moves through space. That trailing plume is what makes up the comet’s magnificent tail that makes it so exciting to watch when a comet comes within view of Earth.
The origins of comets is similarly mysterious. There are a number of theories about where they come from but it is clear that they originate from outside our solar system, somewhere in deep space. Some have speculated they are fragments left over from the organization of planets that get loose from whatever gravitational pull and are sent flying across space to eventually get caught up in the gravity of our sun bringing them into our solar system.
Another theory is that they come from a gaseous cloud called the Oort cloud which is cooling out there after the organization of the sun. As this space debris cools, it gets organized into one body which then gathers sufficient mass to be attracted into the gravity of our solar system turning into a fast moving comet plummeting toward our sun. However, because of the strong gravitational orbits of the many planets in our solar system, the comet does not always immediately collide with the sun and often takes on an orbit of its own.
The life expectancy of comets varies widely. Scientists refer to a comet that is expected to burn out or impact the sun within two hundred years as a short period comet whereas a long period comet has a life expectancy of over two hundred years. That may seem long to us as earth dwellers but in terms of stars and planets, this is a very short life as a space object indeed.
Scientists across the globe have put together some pretty impressive probes to learn more about comets to aid our understanding of these visitors from beyond. In 1985, for example, the United States put a probe into the path of the comet Giacobini-Zinner which passed through the comets tail gathering tremendous scientific knowledge about comets. Then in 1986, an international collation of scientists were able to launch a probe that was able to fly close to Haley’s comet as it passed near Earth and continue the research.
While science fiction writers and tabloid newspapers like to alarm us with the possibility of a comet impacting the earth, scientists who understand the orbits of comets and what changes their paths tell us this is unlikely. That is good because some comets reach sizes that are as big as a planet so that impact would be devastating. For now, we can enjoy the fun of seeing comets make their rare visits to our night sky and marvel at the spectacular shows that these visitors from beyond put on when they are visible in the cosmos.
While it was just a TV show, that little speech at the beginning of the original Star Trek show really did do a good job of capturing our feelings about space. It is those feelings that drive our love of astronomy and our desire to learn more and more about it.
The thing that is most exciting about studying the universe is also the most frustrating and that is that no matter how expert we get, we are always just getting started. But if it’s any consolation, some of the most advanced minds in science and from history always felt that way about space. Even the greats such as Copernicus and Einstein looked up into space and felt like they were just a spec in the presence of such infinity.
USS Enterprise
Of course space is not infinite. It has to be finite which means somehow there must be an end to it. But if there is, nobody on this tiny planet has figured out where it is. The only thing that has brought us to “the end of the universe” is our limited ability to see any deeper into space.
But conquering the final frontier of space means more than just seeing more stars and planets and building the biggest telescope we can. There are some mind blowing concepts about how space works that we have ahead of us to conquer. The big bang and the expanding universe alone was enough to set your mind to spinning. But then we have the coming of Einstein and the theory of relativity to set the entire idea on its ear. All of a sudden space is not just three dimensions but the dimension of time becomes exportable and the twisting and maybe even travel through time seems almost possible.
The frontier of space is as much a journey of the mind as it is of distance. When Steven Hawking showed us the mysteries of black holes, all of a sudden, time and space could collapse and be twisted and changed in those intergalactic pressure cookers. If not for the wonders of radio astronomy, these ideas would remain just ideas but slowly science is catching up with theory.
But the brilliance of mathematicians and genius minds like Hawking and Einstein continue to stretch our concepts of space. Now we have the string theory that could revolutionize everything we know about space, time and how the universe relates to itself. We can’t just say, no, we have discovered enough. It’s the final frontier. The Starship Enterprise would not stop exploring so neither can we. Because there is a hurdle still ahead that has a name but no real answer to it yet. It’s called the Unified Field Theory and those that know tell us that when the Einsteins and Hawkings of our day crack that theory, every other theory will fall into place.
These exciting concepts seem some tools to put the enormity of space in context. That may also be the value of science fiction. Not only are science fiction writers often the visionaries of what comes to be in the future but they give us the idea that space is knowable, that despite how big it is and how small we are, we can conquer this frontier like we have conquered others before us.
For mankind, that is often enough. If we can get the vision that we can conquer something, even if it is something so massive, so impossibly huge, it seems that we are capable of anything. And the love of astronomy, maybe unlike any other force on earth, has brought together mankind toward that common goal of conquering the universe. The quest to establish an international space station and to cooperate on spreading our reach off of this planet seems to find commonality between nations that otherwise cannot get along on the surface of the earth.
That alone may be a reason that we must continue to support astronomy locally and the space program nationally. It is something that seems to bring peace rather than war and make us a better people. But more than that it is as though this is what we were created to do. To reach out to the stars may be our destiny. If so then our love of astronomy is more than a hobby, it’s a calling.
For many of us, our very first experience of learning about the celestial bodies begins when we saw our first full moon in the sky. It is truly a magnificent view even to the naked eye. If the night is clear, you can see amazing detail of the lunar surface just star gazing on in your back yard.
Naturally, as you grow in your love of astronomy, you will find many celestial bodies fascinating. But the moon may always be our first love because is the one far away space object that has the unique distinction of flying close to the earth and upon which man has walked.
Your study of the moon, like anything else, can go from the simple to the very complex. To gaze at the moon with the naked eye, making yourself familiar with the lunar map will help you pick out the seas, craters and other geographic phenomenon that others have already mapped to make your study more enjoyable. Moon maps can be had from any astronomy shop or online and they are well worth the investment.
The best time to view the moon, obviously, is at night when there are few clouds and the weather is accommodating for a long and lasting study. The first quarter yields the greatest detail of study. And don’t be fooled but the blotting out of part of the moon when it is not in full moon stage. The phenomenon known as “earthshine” gives you the ability to see the darkened part of the moon with some detail as well, even if the moon is only at quarter or half display.
To kick it up a notch, a good pair of binoculars can do wonders for the detail you will see on the lunar surface. For best results, get a good wide field in the binocular settings so you can take in the lunar landscape in all its beauty. And because it is almost impossible to hold the binoculars still for the length of time you will want to gaze at this magnificent body in space, you may want to add to your equipment arsenal a good tripod that you can affix the binoculars to so you can study the moon in comfort and with a stable viewing platform.
Of course, to take your moon worship to the ultimate, stepping your equipment up to a good starter telescope will give you the most stunning detail of the lunar surface. With each of these upgrades your knowledge and the depth and scope of what you will be able to see will improve geometrically. For many amateur astronomers, we sometimes cannot get enough of what we can see on this our closest space object.
To take it to a natural next level, you may want to take advantage of partnerships with other astronomers or by visiting one of the truly great telescopes that have been set up by professionals who have invested in better techniques for eliminating atmospheric interference to see the moon even better. The internet can give you access to the Hubble and many of the huge telescopes that are pointed at the moon all the time. Further, many astronomy clubs are working on ways to combine multiple telescopes, carefully synchronized with computers for the best view of the lunar landscape.
Becoming part of the society of devoted amateur astronomers will give you access to these organized efforts to reach new levels in our ability to study the Earth’s moon. And it will give you peers and friends who share your passion for astronomy and who can share their experience and areas of expertise as you seek to find where you might look next in the huge night sky, at the moon and beyond it in your quest for knowledge about the seemingly endless universe above us.
Stan's Hobbies and Interests 