Lesson Two : The Advantages of Radio Astronomy
We have already established that radio wavelengths are much longer than optical wavelengths. The difference in the length of these waves gives radio astronomy many advantages over optical astronomy.An obvious advantage of radio astronomy is that it can be done during the night and under the cover of clouds. Consequently, radio astronomers can work during the day (as well as the night) and are not as dependent upon the weather conditions.
Another advantage of radio astronomy is that more radio waves reach earth than optical waves. Many optical waves are blocked by interstellar dust particles. In addition optical light is subject to distortion by Earth's atmosphere while radio waves are not not. Nor are radio waves obscured by light polution on the planet.
Finally, many objects in space do not emit a significant amount of visible light and can only be studied through their radio waves. For example, the two gigantic clouds of energy emitted the active galaxy Cygnus A are invisble in optical wavelengths but appear quite dramatically when studied in the radio spectrum.
Cygnus A in optical and radio
We acknowledge the use of NASA's SkyView facility located at
NASA Goddard Space Flight Center