Learn About The Telescope And Get Lost In The Stars

Learn About The Telescope And Get Lost In The Stars

There is little in this world that sparks so many musings than that of the night sky. It’s so massive and there is so little that we know of it, it’s nearly impossible to not wonder! Surely we can’t be the only planet that is habitable, right?

It’s that sense of wonder that would have many looking up to the night sky, dreaming of becoming an astronaut, astronomer, astrophysicist or theorist. It’s that sense of wonder that has people purchasing a telescope so they can do their own bit of space observation.

Telescope On Terrace

Today, we want to talk about the tool that makes star gazing that much better – the telescope. The telescope is an optical instrument that has been designed to make things that are far away, look closer.

These devices contain a series of lenses, or a mixture of curved mirrors and lenses. The way we can see objects is thanks to the rays of light that has been collected and focused, thus causing the image to appear magnified.

People have used telescopes for centuries. Mostly, it was used to look out in the distance for hunting, sailing, or even spying on enemies and protecting lands. However, it wasn’t until Galileo that we started using the telescope for star gazing.

The History Of The Telescope 

Many people believe that the telescope was invented by Galileo Galilei in the 1600s, but that is not correct. He didn’t invent the telescope, he was just the first person to look at the sky with one.

Galileo Looking On His Telescope

We don’t know the name of the person who actually invented the telescope, but many historians believe that the discovery of what two lenses could do when held together was made sometime in the late 1500s.

With that said, the first patent for a telescope was submitted by Dutch eyeglass maker, Hans Lippershey in 1608. His device featured a concave eyepiece that aligned with a convex objective lens, thus boasting a 3x magnification.

Galileo hear about Lippershey’s design in 1609 and designed a scope of his own. He made a few improvements on his original design and then he presented the creation to the Venetian Senate, who then were so marveled by his work, double his salary and made him a lecturer at the University at Padua.

When Galileo pointed his telescope to the sky, he was able to see the mountains and craters that made up the moon’s landscape. He was also able to see the Milky Way. He also made the discovery that there were sunspots on the sun and that Jupiter had moons orbiting the gas giant.

The next great improvement to the telescope didn’t come until 1668 when Sir Isaac Newton created the first reflecting telescope. This design used two-inch diameter concave spherical mirror, a flat mirror that was angled, and a convex eye piece.

In 1675, Christian Huygens is credited for developing aerial telescopes, which were just objectives on top of a pole. He also developed a compound negative eyepiece that utilized two air-spaced convex lenses. This creation cancelled some of the chromatic pollution that had a tendency to occur with a single lens eyepiece.

Fast forward several centuries to the 1970s when the European Space Agency and the National Aeronautics and Space Administration (NASA) started to work together to build the Hubble Space Station.

In 1990, a team of 5 astronauts were the Discovery shuttle that deployed the telescope in an orbit about 380 miles from the surface of the Earth. It was then that the Hubble telescope transmitted the astounding images that would make history.

Types Of Telescopes

There are three main types of telescopes that people use to look up at the sky, each having their own list of advantages and disadvantages.

White Refracting Telescope

The Refracting Telescope

These telescopes are basic telescopes that are the most recognizable. These telescopes are great options for beginners because they are the easiest to use and they tend to be more reliable because the optics remain in a fixed position and always aligned.

With that said, these telescopes can be heavy, especially if you are using a telescope with a large aperture. They will also have longer bodies, which will impact its portability and where you can store it. Also, these tend to be more expensive because you’re going to want high quality lenses, which cost more to create.

How Refracting Telescopes Work 

A refracting telescope bends light with the lenses housed in a long tube. The telescope gathers and focuses the light by using an objective lens to make a small picture of the object being viewed. Then the lens in the eyepiece magnifies the image.

The curvature of the lens impacts the quality of the image the telescope produces. The size of that image is going to be directly related to the lens’ focal length. This means that as the focal length increases, the size of the image is going to increase.

This can be a disadvantage because a long focal length means it’s going to be a long telescope, which is going to be harder to transport and store, but it is also going to be heavier and possibly more expensive as well.

Another drawback to the refractor telescopes is their inability to transmit all the light it takes in because some of that light is lost due to absorption or reflecting. Also, these telescopes require a larger lens, which is more difficult to make.

The Reflecting Telescope

A reflecting telescope is like a refracting telescope, except it is a bit more involved. These telescopes got their name because unlike the refracting telescope that uses lenses, this telescope uses mirrors on the inside to reflect the light.

These are decent telescopes – especially if you are traveling or if you’re short on space – because they are more compact. These telescopes tend to be a little more affordable because it does use mirrors.

While there are some pluses to using a reflecting telescope, it’s worth noting that the mirrors in these telescopes are not fixed and they will need to be re-aligned frequently because they can slip out of place with the slightest bump.

Blue Reflecting Telescope

Also, these telescopes are prone to spherical aberrations, which is a form of a defect when light reflects from the edge of a mirror and it doesn’t meet at the same places as the light in the center of the mirror.

How A Reflector Telescope Works

These telescopes are generally made with two mirrors, the large mirror being called the “primary” and the smaller one is called the “secondary.” The primary is typically placed at one end of the telescope and the secondary is placed in the eyepiece’s line of vision. The eyepiece will have a magnifying lens to make the image larger.

Depending on the type of reflecting telescope you have, the two mirrors. This can be a combination of flat, concave, or convex mirrors. When the secondary mirror is flat, it will be placed at a 45 degree angle.

To see an image, the telescope is directed at an object and the light will enter the tube. The light will then hit the primary mirror and that image is reflected to the secondary mirror, which is then reflected to the eyepieces. Here, you will see the magnified image.

The Catadioptric (Compound) Telescope

This telescope is a combination of both the refractive telescope and the reflective telescope. This means it uses a combination of mirrors and lenses to enhance the effectiveness of the focal length, while allowing the telescope to be folded into a size that is more compact and convenient to travel with and store.

The optics used with these telescopes give you the advantages of both mirrors and lenses, thus making it a great all-purpose telescope.

On the downside, these telescopes are prone to losing some light because of where the secondary mirror is positioned. Also, you can experience a jump in focus with these telescopes, as this is a common result of the primary mirror being moved when you’re trying to focus the telescope.

How A Catadioptric Telescope Works

The primary mirror in these telescopes are going to have a deeper curve than your regular reflector telescope. This deep curve brings the focal plane closer to you. The secondary mirror isn’t flat like with a reflector telescope though.; it’s curved outward and takes the last bit of the light cone from the primary mirror and stretches it.

Illustration Of How A Catadioptric Telescope Works

The light is then bounced back through a small hole in the primary mirror where there is a diagonal mirror and an eye piece.

More information about the three types of telescopes can be found in accompanying article also located on this site.

Anatomy Of A Telescope

Every telescope has 3 primary pieces to it:

Lenses And Mirrors

Each telescope is going to have an objective lens and an eyepiece. These components are going to be biconcaved, which means the lens is curved outward on both sides. The objective lens will be located at the end of the telescope that is pointed at the object you are trying to observe. Additionally, the objective lens (refracting telescope) or objective mirror (reflecting & compound telescope) play a vital key role in computing the overall viewing effectiveness of a telescope called the MUM Factor. To learn more about it and why it is so important, be sure to check out our MUM Factor article that describes it is detail.

Eyepiece

The eyepiece is as important as the lens because it is what you are going to look through. When you have a high quality eye piece, this will make the image of what you’re looking at that much clearer and amazing.

If you’re using a handheld telescope, the eyepiece is going to be at the other end of the objective lens. However, if you’re using a larger telescope, it will often be on the side or on top of the telescope.

Optical Tube Assembly

The body of the telescope is called the optical tube assembly. This is where the objective (or objective) is located, and it is the structure that supports it and allows you to look through it.

Diagonals And Prisms

Telescopes are difficult to look through when you’re trying to look at things that are directly overhead. Diagonals or prisms will redirect the light so that it is easier to look through the telescope. The diagonals are either on a plane mirror at a 90 degree angle, or a prism. A prism can reflect light at either 90 degrees or 45 degrees.

Telescope Diagonal

For astronomy, a mirror is more preferred because it is going to reduce the light loss, but if you want a smaller telescope, a prism that corrects the image can be preferred if you want to do terrestrial viewing instead.

Focuser

The focuser is going to be the feature you use to bring the image into focus. This can vary in design from telescope to telescope, ranging from being able to move the eyepiece manually or a motorized system that will move the mirror.

Mount

The mount is what you want to put your telescope on while you are using it. Sometimes you’ll see these called tripods, as they work very similarly. There are two types of mounts that you could choose from:

Equatorial Mount

These mounts are aligned to the Earth’s axis and they move easily in any direction, which makes it easier for you to locate things in the sky. .

Alt-Az Mount

These telescopes in altitude from horizon to zenith and azimuth (North, East, South, West and is measured in how many degrees away from due North).

Finder

The finder is a device on top of the telescope that will help you find what you’re looking for in the night sky. These can be just a few raised bumps, a hollow tube that’s aligned with the tube, or red dot and telrad finders.

Note

Reflector telescopes will have a counterweight, which is a heavy weight that will side up and down on a bar that will balance the telescope so that it is easier to move. The reflector will sometimes also include a motor that will help turn the telescope.

Telescope Motor Drive

Popular Manufacturers

When you are looking to purchase a telescope, you may not want to go with just anything. We recommend purchasing a telescope from a reputable brand, such as these:

Orion Telescopes

Orion Telescopes and Binoculars has been creating top quality products for more than 40 years. They are well known for quality products at a great price and unparalleled customer service.

They offer products for every skill level, meaning both novices and experts can find something that will be useful to them. Other than telescopes, you can find barlow lenses, things for astrophotography, mounts, cameras, and much more.

Meade Telescopes

Meade Instruments is a company that is one of the most well-known and well-respected companies in the telescope industry. They are known for their ground breaking designs and the technological advances they have developed over the years.

They work hard to make the beginner astronomer feel confident as they learn along the way. Other products in their lineup includes a variety of accessories for your telescope, but also binoculars, filters, weather stations and more.

Celestron Telescopes

Celestron has been creating innovative optics for more than 45 years when Tom Johnson introduced the C8, a game changing telescope, back in the 1960s. Since then, Celestron has dedicated all their efforts to continuing his legacy by creating innovative and exciting products with revolutionary technology.

Other products in the Celestron lineup includes items like solar observing gear, astroimaging cameras, mounts, binoculars and much more.

Proper Care And Maintenance For Your Telescope 

Generally speaking, telescopes do not require a lot of maintenance, even if you use it regularly and you take care of it. Here are some tips on how to properly clean and maintain your telescope so that it will last for many, many nights of star gazing.

Washing Telescope Mirror

To Clean

When you want to clean your telescope, you’ll want to follow the manufacturer’s recommendations for cleaning supplies and kits. You don’t want to use tissues, household chemicals, or anything abrasive on the telescope’s optics.

Also, you should avoid compressed air to clean your telescope because the trace chemicals of the aerosol propellant could cause damage to the lens.

The tools you will need include:

  • Soft brush (e.g., a camel hair brush): Use this to gentle sweep any specs of dust or dirt from the lenses and/or mirrors
  • Rubber Bulb Air Blower (e.g., ear syringe): Use this to blow away any dust or lint
  • Cleaning Agent (e.g., distilled water, recommended cleaning solution): Use this to clean the optical components
  • Lens Cleaning Cloth: Use this to wipe the optic surfaces dry

Cleaning Lenses

Cleaning the optics, you’ll want to use a soft brush or an ear syringe to gently sweep/blow away any dust particles that may have collected on the surface. Then you’ll want to lightly dampen your cleaning cloth with the cleaning solution/distilled water. Make sure the lens pointed downward slightly so that any water doesn’t drip into the telescope.

Starting from the center of the lens, use gentle circular motions and work your way out to the edge. Your final wipe should end with an upward lift so there aren’t any smidges left. Let the lens dry completely before replacing the dust covers.

Corrector Plates

The corrector plates on the inside of your telescope isn’t going to need regular cleaning because the inside of the telescope is going to be protected well. Should you have to clean the corrector plates, you should go to someone who has experience removing corrector plates.

Telescope Corrector Plate

Storage

When you are finished using your telescope, you will want to tuck it away and store it somewhere safe. To do this, you will want to have the reflectors facing downward to prevent an excess of dust build up.

The telescope’s lens should be covered with a tight-fitting lens cap, when isn’t being used. You could also cover the entire telescope if you don’t have a lens cap.

Sometimes the lens will dew up if in hot areas. It’s best to keep your telescope in its case with a few desiccant packs to absorb any moisture. Also, keep your case in a temperature controlled room, set at average room temperature. This will prevent mold or mildew from forming.

If you have any extra accessories, lenses, or eyepieces, you should store these in sealed containers that will protect them from damage and dust.

Looking At The Night Sky

Lots of people get started with astronomy just because they happened to look up at the stars one night and they got hooked with what they observed. As a matter of fact, did you know that you can see planets with just your eyes? It's true!  To find out more about which planets you can see and how to do it, check out our article that reveals everything that you need to know.

Kids Are Special Too !

Be sure to check our our special guide that reveals how to choose the best telescope for a child. It is a comprehensive guide that shows what you need to consider before purchasing a telescope for a loved one.

Can You Also Look At Land-Based Objects?

If you're wondering if you can use a telescope for looking at objects that are on land, the answer is, YES! To learn more about what you need for your telescope and how it works, be sure to read our article on using a telescope for terrestrial viewing. 

Astronomy Binoculars?

If you're wondering if binoculars can be used to astronomy, be sure to check out our article that delves into the possibility of viewing the stars and planets above with astronomy binoculars.

Final Thoughts

Being given a telescope as a child is often the catalyst that makes someone become fascinated with space. And it’s no wonder because with a telescope, we able to see celestial bodies in a way that we can appreciate at even photograph!

While there may be three main types of telescopes available today, there are many different versions offered by a number of manufacturers. It’s understandable that someone would get frustrated when they are looking for telescopes – there’s just so many options!

We anticipated this and have created a buying guide that breaks down what you should look for when buying a telescope. We also include five mini reviews of top rated telescopes where we talk about the telescopes features and give you brief summaries of what reviewers had to say about each product. At the end of the guide, we give you our top recommendation.

Looking At Night Sky With Telescope

Leave us a comment below and tell us why you want a telescope. Observing the stars with a telescope can be a lot of fun for the whole family, but it is also a great hobby that can help you relax.

Are you getting one for your child or grandchild? Are you a student? Or maybe you’re an amateur astronomer who just wants to get a better look at the man at the moon? We’d love to know!

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