Optical Astronomy: It is the observation of the heavenly bodies through the optical window. Some of the techniques that are used for this type of study are reflecting telescopes or refracting telescopes. There are lot of dust particles present in air i.e. in the way between the earth and the universe. So, the particles stop the visible lights from entering the telescope.
Radio Astronomy: It is the observation of the heavenly bodies through radio window. In this the most commonly used are the radio telescopes. Besides this radio astronomy have lots of limitations. Some of them are given below:
1. Wavelength of visible light is less. But on the other hand wavelength of radio waves is much more than that of the visible light. So we have to use radio telescopes in it. These are the telescopes which need large circular hole that controls the amount of light entering into the camera for displaying the same information about the heavenly bodies.
2. Radio waves that are discharged by the heavenly bodies when reach the earth, their intensity become too low. So, lots of sensitive detectors are used to detect the radio waves.
3. The power of radio telescope is not very high. So, due to this the complete study of the heavenly bodies can’t be done.
4. The frequency of radio waves coming from heavenly bodies and those which are generated from radio stations present on earth is almost similar. Due to this proper distinction can’t be done and their act of obstructing each other is very common.
Radio astronomy has lot of disadvantages. On the other hand it also has some advantages.Its advantages are discussed below:
1. Low cost devices are used in case of radio astronomy.
2. Radio waves coming from the heavenly bodies present at large distances can arrive on earth due to their property of passing through obstacles like clouds, dust particles. But on the other hand visible waves can’t.
3. Radio telescope has very large aperture, due to this the detection of even small radio signals can be done easily.
4. By using the radio waves, the supervision of the heavenly bodies can be done at any time. It doesn’t matter, whether it is day or night.
