Solar Radiation and Climate Experiment Solar Radiation and Climate Experiment The Solar Radiation and Climate Experiment (SORCE) is a NASA-sponsored satellite mission that measures incoming X-ray, ultraviolet, visible, near-infrared, and total solar radiation. These measurements specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. These measurements are critical to studies of the Sun, its effect on our Earth system and its influence on humankind. The SORCE spacecraft launched on January 25, 2003 on a Pegasus XL launch vehicle to provide NASA's Earth Science Enterprise (ESE) with precise measurements of solar radiation. SORCE measures the Sun's output using
Ionizing radiation In some Environmental Protection Agency references, the ionization of a typical water molecule at an energy of 33 eV is referenced as the appropriate biological threshold for ionizing radiation: this value represents the so-called "W-value", the colloquial name for the ICRU's mean energy expended in a gas per ion pair formed, which combines ionization energy plus the energy lost to other processes such as excitation. At 38 nanometers wavelength for electromagnetic radiation, 33 eV is close to the energy at the conventional 10 nm wavelength transition between extreme ultraviolet and X-ray radiation, which occurs at about 125 eV. Thus, X-ray