RadioWe have artificially produced radio waves for over one hundred years now, but the universe was filled with radio emissions long before that. Astronomers have been able to make useful observations at radio wavelengths for only 70 years or so. Since radio waves are long in wavelength, our radio telescopes must also be huge.
Microwaves We are familiar with microwaves because we use them to heat our food. But microwave astronomical observations will reveal relatively cool objects in the universe, such as interstellar dust.
InfraredWe sense infrared as heat. Infrared has a wavelength slightly longer than visible light. Some predators, such as snakes, are able to locate their prey by the infrared radiation they emit.
VisibleVisible is what we see, of course. Humans have also come to divide visible light into what we call colors. You are perhaps familiar with Roy G. Biv.
UltravioletU.V. radiation has a slightly smaller wavelength than visible light and therefor, slightly more energy. That extra energy can damage skins cells. Fortunately, Earth’s ozone layer saves us.
X RaysWith short wavelengths and high energies, X Rays can do a lot of damage. They are generated in this universe by objects that have temperatures of millions of degrees.
Gamma RaysGamma rays are the most energetic of all electromagnetic radiation. They are generated by the massive explosions called supernovae. In recent decades, we have been puzzled by short bursts of gamma rays in the sky.