Most Common Questions About Telescopes – REVISED

Since I work with the public on a regular basis, and often do outreach events, I get asked these questions about telescopes all the time. This article answers and explains the more complex questions first. Other questions on this article are frequent visitor questions that are either compelling, dumb, or rather snobby.

What is the Power of this Telescope?

In this case, people are asking the wrong question. Usually, what they mean is, “how much is the telescope zoomed in?” or “How much does it magnify?” While I can give a simple numerical answer, it still won’t mean anything if they don’t understand it.

Telescopes are meant to collect light, hence the wider the telescope the more it can collect and resolve finer details. You can actually calculate the telescope’s light gathering power by dividing the aperture by the max width of your pupil, which is 7mm, and then square it.

A 60mm telescope for example has 73x (60÷7²) more light gathering power than your human eye. My 203 mm telescope has 841x light gathering power.

A telescope’s focal length is best thought of like a camera lens – it’s how far zoomed in you are getting. This especially is true when it comes to cameras, as rigging a camera to a 1000 mm focal length telescope essentially turns the telescope into a 1000 mm focal lens. The magnification – is determined by the telescope focal length divided by the eyepiece. You can learn more about telescope magnification by reading the following article: Magnification Viewing Guide for Telescopes.

How Far Can This Telescope See?

Once again, people are not asking the right question.

Remember that a telescope is collecting light, so the correct question is what’s the farthest object bright enough to be seen in the telescope?

Before I give you the answer, let’s understand a few things.

For the brightness of an object, we call it apparent magnitude – or how bright the object appears from Earth. The lower the number, the brighter. All telescopes have a limit in how faint an object can still be to be seen under optimal conditions. This is called your limiting magnitude. Once more, the wider the telescope, the more you can see fainter objects. Anything within the magnitude limit can be observed no matter how far the object is.

There are also plenty of closer objects, such as comets, asteroids, dwarf planets, and even some smaller stars that are simply too small and/or too far away, thus if they are dimmer than the limit, than you can’t see them.

Under a good dark sky, your naked eye’s limiting magnitude is 6.

My 203 mm telescope can pick up objects as faint as mag.14.2 on a good night. This works for any sharp point of light at this magnitude, but for galaxies, the light is spread out, thus appear dimmer than their book value.

Theoretically, my telescope can pick up Quasar 3C-273, which is at magnitude 12.6 and 2.4 billion light years away. Usually, this Quasar is the most distant object an average amateur astronomer can observe. But it won’t look like anything other than a star. Considering the radius of the known universe is 46.6 billion light years, most telescopes can only see the “tip of the iceberg” if you will!

However, don’t forget about sky conditions and especially light pollution – they severely limit your telescope’s capabilities.

So essentially, the answer to all of this is, “it depends on what’s bright enough to pick up, and if you can still see it through the light pollution.”

How Much Does it Cost/ Do I Need an Expensive Telescope?

My whole set up with my main telescope, including the camera and accessories I’ve bought over time specifically for it accumulates to about $1,500 to $2,000.

Good beginner telescopes will minimally set you back a couple hundred bucks. The money starts adding up when you go for more advanced telescopes and/or the accessories that enhance the viewing experiences. There’s other factors to consider, such as your wants, the needs, and who the telescope is for.

You can get a better idea by reading, What Can $200 Get Me On A Telescope Budget?

Can You Point to the Lunar Lander?

No. The moon is too far away and no Earth based telescopes can resolve features that small. It would be like trying to find a pixel in a football field from a mile away!

However, NASA’s Lunar Reconnaissance Orbiter (LRO), a satellite that can dip as low as 31 miles above the Moon’s surface, can easily resolve the landing sites in good detail! Some of the sites still have the modules left intact, and even the tracks left behind their rovers!

Go look it up! It’s a simple Google search that will get you to the correct website!

Why Can’t I see Anything?

woman

  1. Are the dust caps off?
  2. Are you looking through the eyepiece properly? Lots of times people’s eyes are not properly aligned so all they see is black.
  3. The clouds are blocking the object!
What are You Looking For?

Nothing, I already found it!

How Did you Find That?

It’s simple… I know where it is!

If you repeatedly observe the sky, and practice using telescopes, then you too can gain a knowledge of where the planets and other interesting objects are in the sky. It helps to learn the constellations and how to read star charts!

This Looks Small, Can’t You Make it Bigger?
  1. You’re looking at a star. No matter how much I magnify it will always appear like a point of light.
  2. You’re looking a distant or far away planet, so chances are I’m already zoomed in as good as I can.
  3. Yes I can, but I’m not going to. The conditions are limiting how much I can magnify before it gets too distorted.
  4. I’m already at the telescope’s limit. If I magnify any more it’ll just be mushy!
Can You Point it to Something Else?

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While my mouth is saying, “no, sorry,”  I’m internally thinking, “Sure, let me just move the telescope exclusively for you and make the other people behind you wait even longer… wait, no, I’m not doing that!”

Is that it?

Image result for facepalm

No matter how inspiring the object can look in the telescope, we always encounter those who say, “is that it?” Other times they give a disappointed reaction and insert the J-word, “just,” as in, “it’s just the Moon,” or “it’s just a bunch of stars.”

Of course it irritates us, and internally we’re thinking, “well, you came to an observatory or star party offering free viewing through their telescopes, what did you expect to see?”

If you expected Hubble quality pictures from long exposure, your expectations are way too high. If you leave your ego at home and realize the things you can actually still see with your own eyes, then you start enjoying what you’re seeing!

Yes, we started trailing off near the end, but this gives you an idea of what it’s like handling the public when they approach you with your telescope. This can happen at star parties and even observatories! At the end of the day we have to realize that most of the public has little to no knowledge of the heavens, or has never had the chance to even look through a working telescope!

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