Extraterrestrial Noise as a Factor in Space Communications

Present-day refinements in communication systems make it appear that extraterrestrial noise sources may establish a fundamental limitation on long-range communications. The various cosmic and solar system radio sources are considered with respect to their intensities, spectral distributions, and temporal characteristics. The most severe forms of interference occur in the long-wavelength regions of the radio-frequency spectrum, so that the future of space communications probably lies in the perfecting of low-noise microwave systems.