Astronomy is a branch of physics that studies celestial bodies through observatories. Although several tools are used in the process, one of the primary tools is the telescope, which is used to magnify images that are light years away from the Earth. Hence, it is undoubtedly, one of the most important instruments used to study and analyze celestial objects. Furthermore, telescopes not only help in observing heavenly bodies, but they also help in analyzing the radiation signals caught by them.
The first telescope was invented by Galileo in the 17th century, which revolutionized the study of astronomy to study extraterrestrial bodies. Before the telescope’s invention, magnifying objects were never used to study and observe celestial bodies. Since then, many optical telescopes have been invented to learn about objects in electromagnetic spectra. In addition, other tools like cameras, charge-couple devices, the spectrograph, electronic computers, spacecraft, rockets, and many other instruments are used in conjunction with the telescopes to understand celestial bodies in the solar system, Milky Way galaxy, and beyond. In this article, let’s learn more about the different types of telescopes and their brief working principles.
These are also called refractors, which bend light when passing from one medium to another (from air to glass, etc.). Refractors are used to observe the moon, Jupiter, Mars, and other binary stars. The light from a celestial object passes through the objective lens and is inverted at the focal plane. At the eyepiece lens, the observer can view the magnified and inverted image of the celestial body. Many refractors also have a small lens after the eyepiece to erect the picture upright. Since any disturbances and shakiness of the telescope will also be magnified, these telescopes are mounted firmly on a platform.
These telescopes reflect the light back to the focal point and generally use parabolic or concave spherical mirrors to examine light in the visible region of the EM spectrum. In many ways, reflecting telescopes provide more advantages over refractors. One of the main advantages is that they are not subjected to chromatic aberration, making it easy for astronomers to capture the right colors. The Newtonian reflector, where a mirror is placed at a 45-degree angle near the eyepiece, is the most widely used and popular of all the reflecting telescopes.
The Schmidt telescope
In 1930, Bernhard Schmidt, an optician at the Hamburg Observatory in Germany, discovered the Schmidt telescope. This telescope allows astronomers to photograph the larger celestial areas of an object, inducing the best features of both the telescopes mentioned above. It was first used by the National Geographic Society, which made use of a 1.2-meter Schmidt telescope to photograph the blue and green regions of the northern sky in the visible spectrum.