Webb Telescope Optics Meet Expectations

The James Webb Space Telescope team has announced that they’ve completed a key stage in deploying its primary mirror. Find out why NASA now confirms that the telescope’s audacious design will deliver on its demanding science goals.

I still have the first telescope I bought at the now defunct Efston Science store in Toronto about thirty years ago. The Edmund Scientific Company (also now defunct) produced that basic but easy to use 75mm (3 inch) Newtonian reflector.

Columnist Alex Berezov has made the case that Sir Isaac Newton was “the smartest person who ever lived.” He contributed to many fields, but for this story, we’ll focus on his Newtonian telescope design.

The Newtonian telescope uses mirrors instead of lenses. There’s a large, round, concave mirror at the back of the tube that reflects the light to a smaller mirror near the front.

Newtonian Telescope Uses Mirrors Instead of Lenses

The light then passes vertically through an eyepiece to the observer. Newton’s design eliminates the distorted colours we tend to see with lenses.