Infrared thermal radiation of Venus

Data on peculiarities of the infrared thermal radiation from Venus, obtained on the base of the ground and airborne measurements are given. The average value of the planet spherical albedo equals 0.766+-0.018 (228 K effective temperature). The equatorial and latitudinal distributions of escaping radiation are tabulated. The Venus thermal radiation is subject to an intensive effect of darkening at the edge, the nature of darkening being different for various longitudes and latitudes. Some specificities are characteristic of the polar region radiation. The solar-related (daily) component is clearly manifested, the night time planet radiation somewhat exceeding the daytime radiation. Numerous data testify to the variability of Venus thermal radiation global characteristics during the period of one year or several years. Such variability is supposed to be related to comparatively short flashes of aerosol particle formation in the atmosphere caused by a sharp increase of the Venus volcanic activity