Observing over the entire electromagnetic spectrum
		• Different phenomena produce different wavelength waves – Ordinary stars:  Visible light – Cool planets or dust clouds:  Infrared light – Moving charged particles, cool molecules:  Radio waves – Very hot objects:  X-Rays and Gamma Rays – Quasars: ALL wavelengths • Only visible, some IR, and radio make it through atmosphere – Need to observe from space for other wavelengths • Going into space also lets you obtain more detailed images – On Earth telescope size isn’t only limit on image resolution – Temperature fluctuations in atmosphere cause “seeing” (blurring)