HOW THE TELESCOPE WAS INVENTED
Follow the timeline to discover centuries of advancement in the way we observe the universe
WORDS AILSA HARVEY
DID YOU KNOW?
Galileo based the first astronomical telescope on Hans Lippershey’s 1608 invention
GALILEO’S EARLY VISION
Over 400 years ago, the telescope was first used for astronomical observations
1 EYEPIECE The eyepiece was a concave lens that was used to magnify the image from the lens opposite.
2 OBJECTIVE LENS The larger end had a convex lens. This focused the light from distant objects into the telescope.
3 BODY The main tube of the telescope was wooden and kept the lenses at an optimal distance. Galileo’s telescope was around one metre long.
4 MOUNTING BRACKETS These wooden rings held the lenses securely in place for a clear image.
5 SLIDING TUBE The tube had an external covering so that it could be elongated or shortened. This enabled the user to focus the image by changing the distance between the lenses.
CLARITY WITH KEPLER
1611
German astronomer Johannes Kepler improved the magnification of Galileo’s telescope, which had a magnification of just 30 times. Rather than using a concave lens for the eyepiece, Kepler’s telescope used a convex lens. A convex lens is thicker in the middle than it is at the edges, helping focus light to one point. As a result, Kepler’s telescope produced much clearer images.
However, these clearer images were flipped upside down. As the light rays crossed the focal point, rays at the top were bent downwards and those at the bottom were bent upwards. The same happened vertically across the focal point, producing an inverted image.