How Do Telescopes Work? Fascinating Lens Facts For Curious Kids!

Anusuya Mukherjee
Jan 24, 2024 By Anusuya Mukherjee
Originally Published on Oct 29, 2021
Monocular telescope at sunset
Age: 3-18
Read time: 4.3 Min

The word ‘telescope’ is from an Ancient Greek word that means ‘far’ and ‘to look and see’.

A telescope is used to watch objects from a distance. Magnification is the main function of a telescope.

Telescopes have always seemed fascinating to kids but how do they work?

The earliest known telescope dates back to 1608 when its patent was submitted to the government in the Netherlands. As all of the traditional telescopes worked with lenses, the creative minds joined the race of making better ones using mirrors for smoother production and clearer images. The achromatic lens was invented in 1733 which corrected the color aberrations in the lenses used in telescopes beforehand. Reflecting telescopes use mirrors while refracting telescopes use lenses to focus light rays. A telescope lets you gather information on even the most distant stars.

After reading all about telescopes and their lenses, do read how do ships float and how do mirrors work?

How do telescopes magnify?

How telescopes work is a question that many of us come across but rather conveniently ignore. Do you ever use a telescope and wonder how it functions? For the magnification of an object, a reflecting telescope has to collect the light rays coming from the object and magnify them. The better a telescope can gather light, the clearer and brighter the image of the object will be. The characteristic that lets a telescope collect light is known as its diameter or its aperture.

There are three types of telescope:

A reflecting telescope is one that uses mirrors to collect and focus light. Unlike a refracting telescope, these Newtonian telescopes (the reflecting telescope was founded by Isac Newton) don’t use a lens to make an image. The use of mirrors ensures ease in creating an image as they are lighter than a lens and can be shaped smoothly. The fact that reflecting telescopes use mirrors and not lenses give them an edge over a refracting telescope. The type of mirrors that a reflecting telescope needs are spherical and concave. The primary mirror in reflecting telescopes makes them better to use. These mirrors are the reason why reflecting telescopes are considered the best to own.

A refracting telescope uses lenses to magnify an image at a focal point. While the optical telescope was invented by Galileo Galilei (as he was the first person to observe a night sky with a telescope), the credit of inventing refracting telescopes goes to Hans Lippershey. The curved lens in refracting telescopes focuses the light down towards a tube, along with the second lens that is also known as an eyepiece. A refracting telescope consists of an eyepiece. The earliest of the telescopes were all the refracting ones.

Catadioptric telescopes are the most modern type of telescope and were invented as recently as the early 20th century. These combine mirrors and lenses to form an image. In addition to their small and handy design, this telescope makes light fold to make it focus, rather than making it travel all the way down like traditional telescopes.

Telescope on the roof

What makes a telescope more powerful?

The power of your telescope will depend on its focal length. The longer the focal length is, the smaller the field of view is, making the image larger along with it.

As the size of the mirrors and lenses used in a telescope grows bigger, the amount of light that it can capture increases, making it more powerful.

How do space telescopes work?

Once you get the hang of how telescopes work, you may begin to wonder if space telescopes work in the same way, considering the big difference in the uses of these telescopes. A space telescope, or a space observatory like the Hubble space telescope, is located in space to observe all types of astronomical objects. The observatory is useful to identify various objects in space and focus on their details. The most famous space telescope, the Hubble space telescope, is a telescope that was launched into the lower orbit of Earth in 1990 and is in operation to this date. Although it wasn’t the first telescope located in space, it soon became the most significant one. Named after astronomer Edwin Hubble, this telescope is one of NASA’s great observatories.

What two lenses are needed to make a telescope?

It is impossible for a kid who is into astronomy to not have tried making a telescope at home. So, what do you think, can you make a telescope at home? With the right method, nothing can stop you.

Two types of lenses, namely the ‘optical lens’ and the ‘eyepiece lens’, are needed to construct a telescope.

Watching the night sky with a telescope may make you feel like an astronaut. With materials like two magnifying glasses (for the aperture), a cardboard tube, scissors, a ruler, and sheets, you can make yourself a basic telescope at home.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for how do telescopes work? curious lenses facts for budding kids! then why not take a look at how long do glofish live? Fin-tastic tetra aquarium facts for kids! or bobcat vs mountain lion: difference between big cats simplified!

We Want Your Photos!
We Want Your Photos!

We Want Your Photos!

Do you have a photo you are happy to share that would improve this article?
Email your photos

More for You

See All

Written by Anusuya Mukherjee

Bachelor of Arts and Law specializing in Political Science and Intellectual Property Rights

Anusuya Mukherjee picture

Anusuya MukherjeeBachelor of Arts and Law specializing in Political Science and Intellectual Property Rights

With a wealth of international experience spanning Europe, Africa, North America, and the Middle East, Anusuya brings a unique perspective to her work as a Content Assistant and Content Updating Coordinator. She holds a law degree from India and has practiced law in India and Kuwait. Anusuya is a fan of rap music and enjoys a good cup of coffee in her free time. Currently, she is working on her novel, "Mr. Ivory Merchant".

Read full bio >