To observe celestial bodies and study them, mankind uses telescopes - devices that allow you to "see" a distant object by collecting information about its electromagnetic radiation.
The telescope is designed to observe remote space objects, such as:
- planets;
- asteroids;
- comets and meteors;
- stars and their clusters;
- galaxies;
- nebulae.
All these space objects are located at a considerable distance, and a powerful optical device is required to study them. The telescope, which was invented in Holland in 1608, became such a device. The first consisted of the simplest lenses and had very meager capabilities by modern standards, but at that time it was a significant breakthrough in the study of space.
Lens and mirror telescopes
The most widespread are lens telescopes, which are based on the principle of refraction, that is, the refraction of light and focusing it at one point. Lens telescopes are the cheapest, but they have disadvantages such as aberrations, that is, distortion of the visible image.
The next generation of telescopes is SLR. Their action is based on a lens in the form of a spherical mirror, which collects rays of light, and then reflects them towards the lens. These telescopes are becoming more widespread due to the low cost of their manufacture. Also, with the help of mirror telescopes, it became possible to take photographs of the objects under study.
Radio telescopes
In connection with the development of modern technologies, fundamentally new types of telescopes began to appear, such as radio telescopes, which make it possible to study very distant space objects. They are based on a paraboloid bowl made of metal. A radio signal transceiver is installed in the bowl, which sends a signal for further processing to a computer complex. The principle of their work is based on the reflection of the sent signal from the object under study.
The advantages of these telescopes include the fact that they can be used to study celestial bodies in any weather on Earth. Also, with the help of radio telescopes, the accuracy of research is increased, since all data is processed without human intervention, that is, scientists see ready-made research output data that cannot be interpreted otherwise due to the peculiarities of the perception of an object by human vision.
Infrared telescopes
Infrared telescopes have also become widely used in astronomical research recently. These types of devices register thermal radiation from space objects. The disadvantage of such telescopes is that they can only study objects that emit heat, for example, the planets of the solar system.
In connection with the development of astronautics, telescopes to improve the quality of observation began to be put into Earth's orbit in the form of satellites. The most famous orbiting telescope is the Hubble Telescope. Orbiting, that is, space telescopes, are most often of three types:
- radio telescopes;
- infrared telescopes;
- gamma telescopes.
