he telescope is an astronomical instrument. It is used to see distant objects in space. The
one of the central instruments of the Scientific Revolution of the 17th century.
It was made popular by Galileo Galilei in 1609. first practical refracting telescopes were
invented in the Netherlands around 1608, These telescopes were credited to three
individuals- Hans Lippershey and Zacharias Janssen, spectacle-makers in Middelburg,
and Jacob Metius of Alkmaar also known as Jacob Adriaanszoon. The first reflector
telescope was made by Niccolo Zucchi,an Italian monk, in 1616.
Types of telescops There are two types of telescops: refractor telescops and reflector
telescops. Refractor telescops are very large in size They use lenses only and do not use mirrors. Reflector telescopes use mirrors.
Johannes Kepler in his book Dioptrice showed that a telescop could also be made by combining a con vex objective lens and a convex ocular len Kepler mentioned that such a combination would produce an inverted image and by adding a third convex lens one can have an erect image.
Galileo made his first telescop in 1609. It could magnitfy objects three times. After his first telescop, Galileo made another one that could magnify objects 20 times. Galileo began to observe the skies with his telescop. He became the first man to see the craters of the moon. He went on to discover sunspots, the four large moons of Jupiter, and the
rings of Saturn using his telescop. He also observed a supernova and verified the phases of Venus.
The Hale at the Palomar Los Angeles is the best-known giant. It is 5.1 m long. The telescope is named after George Ellery Hale, who supervised the construction of telescopes at the Mount Wilson Observatory. It remained the world’s largest effective for 45 years. Giant telescops, like the Hale are used as massive cameras to record images on photographic film. They can be used to detect very faint stars and galaxies.
Hubble Space Telescope
The Hubble Space (HST) is a large space-based observatory. It was launched in
1990. It orbits the Earth every 97 minutes, 571 km above the Earth’s surface. The telescop has provided clear images of remote galaxies and the solar system.
Reflecting telescops are optical telescopes that use mirrors instead of lenses. They are also called reflectors. The reflecting telescope was invented by the great scientist, Sir Isaac Newton. The telescop uses two mirrors that magnify the objects
Catadioptrics are telescops that use a combination of mirrors and lenses to fold the light path and direct it for focus and magnification through a hole in the primary mirror. There are two popular designs of catadioptrics: the Maksutov-Cassegrain catadioptrics and the Schmidt-Cassegrain catadioptrics. Catadioptric telescopes combine the optical advantages of both lenses and mirrors while overcoming their disadvantages. They provide razor sharp images and are excellent for deep sky observations or astrophotography. They are very good for the purpose of observing or photographing lunar or planetary phenomena and binary stars. Most catadioptrics are extremely compact and portable. They are easy to use and have a long life. They are the most versatile kinds of telescops.