Charles Y. Johnson

DETECTION OF LYMAN-

A rocket-borne photometer has detected far ultraviolet night glow radiations that are identified as Lyman-β (HI 1026 angstroms), and the helium lines at 304 or 584 angstroms, or at both. At an altitude of 227 kilometers the measured intensity for Lyman-β was about 10 rayleighs. The discrimination characteristics of the broad-band helium radiation filter give helium line intensities, at 227 kilometers, of 4.8 and 12 rayleighs, respectively, pending identification of the wavelength of the radiation as 304 or 584 angstroms. These ultraviolet radiations appear sufficient to maintain the night E and F1 regions of the ionosphere.