A very unenergetic wavelength, or frequency, of light. Microwaves are a type of radio radiation, meaning that they are less energetic than infrared radiation. They are not harmful to life because they are not strong enough to ionize atoms or destroy cells. While the Earth's atmosphere shields us from some microwave radiation, it does allow some frequencies to pass through. Astronomers study these microwaves with large radio telescopes or antennas, which resemble giant satellite dishes.