..if you wish to see the planets with detail! They may help you by preventing you from being wiped off of the face of the Earth by a bus, but when it comes to inspecting the Moon and making conspiracy theories to as why there appears to be a face on the Moon.. You’ll need a telescope!
In the picture above we see the great Sir Patrick Moore with his 15ins telescope at his house in Farthings, Selsey, 30 years ago. I’m going to assume that most of you have heard of Patrick Moore, especially after the unfortunate, yet inevitable, death. You may also know that he was an English amateur astronomer that was indeed quite fond of telescopes.
However, this article isn’t focusing on Patrick Moore, but more on how telescopes work and the different types of telescopes. If you wish to read up on him, then this is quite a good article.
Different types of Telescopes? Surely you’re not telling me that there’s MORE than one type of Telescope?!
You have much to learn, young Padawan. There are many different types of telescopes: Optical telescopes, Radio telescopes, X-ray telescopes, Gamma-ray telescopes, High-energy particle telescopes, etc. I’m going to focus on Optical telescopes and there are three main types of these: Refractors, reflectors and the compound/catadioptric telescope.
The type of telescope is determined by the part of the telescope that gathers light. This part is called the objective. Refractors use a glass lens as its objective, so that the glass lens is at the front of telescope and light is bent/refracted as it passes through this lens. A reflector uses a mirror instead as its objective. The mirror is close to the rear of the telescope and light is bounced off/reflected off as it strikes the mirror. Compound telescopes use both mirrors and lenses to collect and focus the incoming light.
Which one is the best telescope for me?
Well, it depends on what you’d like to see. Refractors are known for sharp, detailed and well-contrasted images. They are said to be best for viewing the moon and planets. A small refractor of 60 mm to 80 mm aperture will make a good starting scope to observe the Moon and planets. They’re portable and inexpensive and a refractor is possibly the best choice if you will be doing most of your observing from the city or suburbs, where there is light pollution.
Newtonian reflectors are great-all around scopes that aren’t too expensive either. You can view both planetary and deep-sky viewing; however, these scopes are more fragile and require more maintenance than the others.
Compound telescopes/catadioptrics are said to be the most versatile telescopes and have the best all around, all-purpose design. They tend to be very portable and compact, and if you use them in the right situations (away from light pollution with a clear night sky), then you should be able to see excellent views of the Moon, planets and faint deep sky objects such as clusters, galaxies, nebulae comets, etc. This is probably the most suited telescope for astrophotography, yet you’ve got to pay the slightly expensive price for one of these.. However, to quote spacephilosopher “You lose your house, but you get the Universe”.
Unfortunately, telescopes don’t float around in the air and position themselves perfectly for us… yet. They need to be supported by some type of stand, or mount, unless you feel like doing a bit of weight-lifting. There are two basic types of telescope mounts: Alt-azimuth and Equatorial.
The alt-azimuth mount is similar to a camera tripod, it uses a vertical (altitude) and a horizontal (azimuth) axis to locate an object. This type of mount is simple to use, but it doesn’t track the motion of stars properly. When it tries to, it produces a “zig-zag” motion instead of a smooth arc across the sky. This makes this type of useless for taking photographs of the stars.
The equatorial mount uses two axes (right ascension, or polar, and declination) aligned with the poles to track the motion of an object across the sky. Instead of being orientated up and down, it’s tilted at the same angle as the Earth’s axis of rotation.
The Sky at Night book - Sir Patrick Moore & Chris North (Worth buying)