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1609
On hearing about this new instrument, Italian physicist Galileo Galilei builds his own. He improved Lippershey’s design and using his new telescope the following year, he discovers the four largest moons of Jupiter (Io, Ganymede, Callisto and Europa), sunspots on the surface of the Sun, the phases of Venus and physical features on the Moon - such as craters. -
1616
Italian priest and astronomer Niccolo Zucchi creates a concave spherical mirror (a mirror that bulges inwards - very much like a cave!) to magnify objects and he used it to discover Jupiter’s belts 14 years later. -
1630
German priest and astronomer Christoph Scheiner builds a telescope based
on a design that astronomer Johannes Kepler made in 1611. Kepler’s design
improves on Galileo’s by replacing the concave lens with a convex lens (a
lens that bulges outwards). This helped to reduce spherical aberration.
Astronomers find spherical aberration quite annoying as it means that they
do not get perfect images when they look through their telesco -
1655
Inspired by the observations of Jupiter made by Galileo, Dutch astronomer Christian Huygens builds the most powerful telescope ever and uses it to view the planets in our Solar System. He spotted a bright moon in orbit around Saturn and called it “Saturni Luna.” All astronomers used this name until 1847 when John Herschel (famous astronomer William Herschel’s son) decided that the moon should be called Titan. Huygens studied Saturn much more with his telescope and discovered the true shape of th -
1666
After studying the reflection of light through prisms, Sir Isaac Newton
decides that the problem of chromatic aberration cannot be solved. He
makes an improved version of the reflecting telescope. -
1672
Laurent Cassegrain, a catholic priest from France, develops a telescope that
bears his name - the Cassegrain telescope. This instrument uses mirrors that
are called hyperbolic and parabolic mirrors.