How Do Astronomers Use Radio Waves?

Unlike the common misconception, radio waves are not something that we can hear. They are a form of radiation that make up a small part of the electromagnetic spectrum, along with the visible light that we see with our eyes, microwaves, ultraviolet light, infrared light, X-rays, and gamma rays.

Out of all the waves in the electromagnetic spectrum, radio waves have the lowest frequencies and longest wavelengths that can range from 1mm long to a size larger than our planet. They travel at the speed of light and can penetrate through surfaces that visible light can’t.

How Do Astronomers Use Radio Waves in Astronomy?

Nearly all types of astronomical objects give off some radio radiation and because of this, radio waves since their discovery have played a significant role in studying the universe and the objects within it. Radio Astronomy, through radio telescopes, makes use of radio waves to get a clearer and better understanding of distant planets, stars, black holes, and other cosmic objects. 

Some of the most important discoveries in astronomy have been made by studying radio waves from space. In 1965, radio astronomers discovered pulsars, which are rapidly spinning neutron stars that emit a beam of radio waves. This discovery helped confirm the existence of neutron stars and also showed that they could be strong sources of radiation.

Pulsars are not the only type of astronomical object that gives off radio waves. Black holes, for example, emit powerful jets of energy and particles that release enormous amounts of radiation across the electromagnetic spectrum, including radio waves. By studying these objects using radio telescopes, astronomers have been able to learn more about the nature of black holes and how they interact with the matter around them.

Other Applications of Radio Waves

Radio waves can be classified into different classes based on their frequency, but their widespread use is in communication, such as broadcasting television and radio. These include Very High Frequency (VHF) between 30 and 300 MHZ and wavelength between 1 to 10 m. Due to their small wavelengths, these waves use small transmitting antennas that can be fitted on a car or building.

Another wide and signification application of radio waves is in wireless networks such as Wi-Fi, Bluetooth, and our mobile phones. Even shorter than VHF, these applications use UHF (ultra high frequency) with wavelength ranging between 10cm to 1m. They use even smaller transmitting antennas that can fit handheld devices that we use daily such as phones, walkie-talkies, and GPS. Their small wavelength, however, makes them prone to a loss of quality due to interferences such as walls, trees, and rain. This can result in poor or intermittent reception depending on the location and weather.

Moreover, radio waves are used for radar technology which is a system that uses electromagnetic waves to detect the range, speed, and other characteristics of objects such as aircraft or ships.


Radio waves are used for a lot of significant real-life applications, such as communication and wireless networks. Additionally, they play a big role in better understanding the universe through radio astronomy. As technology advances, we will find more and more ways to put radio waves to good use.

Andy Morgan