Spectrophotometry of Jupiter's 3400–10000 Å spectrum and a bolometric albedo for Jupiter

Abstract Photoelectric measurements of the monochromatic flux from Jupiter in the region from 3400 to 10 000 A are reported. From these measurements and published data for the ultraviolet and infrared outside the region of measurement a bolometric geometrical albedo of 0.28 was obtained. With an adopted bolometric phase integral of 1.6 the bolometric Bond albedo is then found to be 0.45, corresponding to a temperature of equilibrium with absorbed sunlight of 105°K. If the difference between this temperature and the radiometric temperature of 128°K is due to heat from the interior the mantle is probably melted. Rough calculations suggest that even with convective cooling the initial contraction energy could explain the present radiometric temperature. Radioactivity, meteor bombardment, tidal friction, and magnetic field decay do not appear to be feasible alternative energy sources for the radiometric temperature. A simple interpretation of the radiometric temperature is that Jupiter is radiating only absorbed sunlight with a temperature of 145°K and emissivity of 0.27.