Observing Stars Our view of the sky at night is possible because of the emission and reflection of light. 'Light' is the better-known term for the electromagnetic spectrum, which includes waves in the visible, ultra-violet, infra-red, microwave, radio, X-ray and gamma-ray regions. The scale of the spectrum is so large that no region is distinct, several overlap each other. Each of these regions in the electromagnetic spectrum represent transverse waves, travelling as electrical and magnetic fields which interact perpendicularly to each other, with different ranges of wavelength. …