Learning how to make a telescope can be a fun project for amateur astronomers, but before you begin it's good to learn how a telescope works. A telescope is simply a device that collects light from a distant object by employing either an objective lens or a mirror. After the lens or mirror brings the image into focus, it can be viewed through the eyepiece of the telescope.
There are two main types of telescopes: reflecting and refracting. A refracting telescope, sometimes called a Galilean Telescope, has a glass lens at the front. Light passes through the lens and it is bent (refracted) along the way, collecting in the center of the lens, where it can be viewed. A reflecting telescope, also known as a Newtonian Telescope, has a mirror in the the back. Telescope eyepieces mounted on the side of a reflecting telescope let you see the light that collects on the mirror. The Dobsonian telescope is a type of reflecting telescope popularized in the 1960s by astronomer John Dobson.
Building Your Own Telescope
A refracting telescope can easily be built from inexpensive everyday items. This telescope won't have the same magnification as a store-bought refractor, but it's a great introduction to the design principles that make telescopes work.
Materials Needed:
Assembly:
Get two magnifying glasses and a sheet of printed paper, such as a newspaper or magazine page. Hold the larger magnifying glass between your eye and the paper. The image should be blurry. Place the smaller magnifying glass between your eye and the first magnifying glass.
Move the second glass forward or backward until the print comes into sharp focus. The print will be upside down and quite large. Once the print is in sharp focus, measure the distance between the two magnifying glasses.
On the cardboard tube, cut a slot (do not cut all the way through the tube) about an inch from the end. This slot will hold the large magnifying glass. Cut a second slot in the tube at the same distance you measured between the magnifying glasses. This slot holds the smaller magnifying glass.
Tape the two glasses into their slots, then cut off all but one inch of the tube behind the small magnifying glass. You should now have a working telescope.
 | To choose a telescope, you don't need a degree in astrophysics. You just need a basic understanding of measurements and how it works. |
Check our picks in this telescope use beginner's guide, for the best beginner telescope for a child, based on price, ease of use and durability. |
How does the Hubble telescope work? The Hubble telescope gained a reputation years ago when its primary mirror had a design flaw, but that has been remedied, and now the Hubble can capture amazing images in space. |
How do telescopes work? In general, telescopes use either lenses or mirrors to capture light. By focusing that light, a small, distant object appears larger. |
Who invented the telescope? The usual suspects include Galileo and Isaac Newton, but many others have also helped improve telescope technology. |
