How does it work?
So, it’s called a Newtonian, because of who invented it. But
it’s also called a “reflector,” because of how it works. At the
heart of the Newtonian telescope is a system of mirrors that
gather and reflect light to your eye. Luckily, the Celestron
STEM Newtonian 50mm Telescope has a removable panel
on one side, so you can see the inner mirrors for yourself.
Here’s how the telescope works:
Your eyes take in light from the world around you and form
images that are sent to your brain, allowing you to SEE the
objects you are looking at. The Newtonian telescope uses
mirrors to reflect that light in a small space (the telescope
tube) and direct it through the eyepiece, magnifying the
object before it reaches your eye.
The light enters the telescope tube at the open end, travels
all the way to the primary mirror, at the opposite end of the
tube, where it is reflected to the secondary mirror. The
secondary mirror is mounted at a 45° angle, which diverts
the light to the eyepiece.
The eyepiece magnifies the image and passes the image to
your eye.
LIGHT
LIGHT
Primary Mirror
Secondary Mirror
What is a Newtonian Telescope?
You might be asking “why is this called a Newtonian
telescope?” Well, it’s because it was invented by Sir Isaac
Newton himself. In case you didn’t know, Sir Isaac was one
of the world’s most renowned Scientists and Philosophers.
Around 1668, in-between formulating the laws of gravity,
advancing calculus and discovering that white light is made
up of ALL colors, he took some time to create a better
telescope design that would cut out “chromatic aberration”
(blurry images). He did this by removing lenses and replacing
them with mirrors. This basic design is still used today, some
350 years later!
Sir Isaac Newton
Now that you know the history, get out there and use your Celestron Kids Newtonian Reflector telescope. Start by pointing at
the moon, or stars, and remember:
NEVER LOOK AT THE SUN THROUGH YOUR TELESCOPE. PERMANENT DAMAGE TO
YOUR EYES MAY RESULT
How to Determine your Telescope’s Magnification
To determine the magnification level of your telescope with a given eyepiece, use this simple calculator:
FOCAL LENGTH OF TELESCOPE (FL(T)) ÷ FOCAL LENGTH OF EYEPIECE (FL(EP)) = MAGNIFICATION (MAG)
FL(T) ÷ FL(EP) = MAG
Your Celestron Newtonian STEM Telescope has a 200mm focal length. The eyepiece included is a 10mm eyepiece. Can you
figure out what the magnification is?
÷
=
