A wavelength, or frequency, of light that is more energetic than visible light, but less energetic than x-ray radiation. Ultraviolet, or UV, radiation ranges in wavelength between 10^-8 and 10^-7 meters and in frequency between 10^15 and 10^17 Hz. UV rays can be very harmful to life because they are strong enough to ionize atoms and destroy cells. Fortunately, the Earth's atmosphere shields us from most UV radiation. Astronomers who want to study UV light from celestial sources must do so from space-borne telescopes, such as the Hubble Space Telescope.