EUV continuum radiation(10–30 nm) arising only from very low energy pulsed pinch gas discharges comprising some hydrogen was first observed at Black Light Power, Inc. and reproduced at the Harvard Center for Astrophysics(Cf A). The source was determined to be due to the transition of H to the lower-energy hydrogen or hydrino state H(1/4) whose emission matches that observed wherein alternative sources were eliminated. The identity of the catalyst that accepts 3 · 27.2 eV from the H to cause the H to H(1/4) transition was determined to HOH versus 3H. The mechanism was elucidated using different oxide-coated electrodes that were selective in forming HOH versus plasma forming metal atoms as well as from the intensity profile that was a mismatch for the multi-body reaction required during 3H catalysis. The HOH catalyst was further shown to give EUV radiation of the same nature by igniting a solid fuel comprising a source of H and HOH catalyst by passing a low voltage, high current through the fuel to produce explosive plasma. No chemical reaction can release such high-energy light. No high field existed to form highly ionized ions that could give radiation in this EUV region that persisted even without power input. This plasma source serves as strong evidence for the existence of the transition of H to hydrino H(1/4) by HOH as the catalyst and a corresponding new power source wherein initial extraordinarily brilliant light-emitting prototypes are already producing photovoltaic generated electrical power. The hydrino product of a catalyst reaction of atomic hydrogen was analyzed by multiple spectroscopic techniques. Moreover, the m H catalyst was identified to be active in astronomical sources such as the Sun, stars and interstellar medium wherein the characteristics of hydrino match those of the dark matter of the Universe. EUV continuum radiation (10-30 nm) arising only from very low energy pulsed pinch gas discharges including some hydrogen was first observed at Black Light Power, Inc. and reproduced at the Harvard Center for Astrophysics (Cf A). The source was determined to The due of the transition of H to the lower-energy hydrogen or hydrino state H (1/4) whose emission matches that observed alternative sources were eliminated. The identity of the catalyst that accepts 3.27.2 eV from the H to cause the H to H (1/4) transition was determined to HOH versus 3H. The mechanism was elucidated using different oxide-coated electrodes that were selective in forming HOH versus plasma forming metal atoms as well as from the intensity profile that was a mismatch for the The multi-body reaction required during 3H catalysis. The HOH catalyst was further shown to give EUV radiation of the same nature by igniting a solid fuel comprising a source of H and HOH catalyst by passing a low voltage, high current throu No high-field consumed to form highly ionized ions that could give radiation in this EUV region that persisted even without power input. This plasma source serves as strong evidence for the existence of the transition of H to hydrino H (1/4) by HOH as the catalyst and a corresponding new power source where initial extraordinarily brilliant light-emitting prototypes are already producing photovoltaic generated electrical power. The hydrino product of a catalyst reaction of atomic hydrogen was analyzed by multiple spectroscopic techniques. Moreover, the m H catalyst was identified to be active in astronomical sources such as the Sun, stars and interstellar medium where the characteristics of hydrino match those of the dark matter of the universe.