The Orion Nebula, in a composite image. This giant cloud of gas and dust is a starbirth region; the area covered by this image is around 3 light years across. The nebula is seen here at radio wavelengths (purple), as observed by the Very Large Array (VLA). Image courtesy NASA / CXC / SAO / S.WOLK ET AL / NSF / NRAO / VLA / Science Photo Library.

The study of how light (or the ‘electromagnetic spectrum’) interacts with matter is called spectroscopy. Most wavelengths of light are not visible to humans, so we must build instruments to detect these “invisible” wavelengths. One such example is radio waves.

If you would like to learn more about radio astronomy, visit the National Science Foundation’s National Radio Astronomy Observatory here.