Number 253 (Story #3), January 4, 1996 by Phillip F. Schewe and Ben Stein A GIGANTIC CELESTIAL MASER provides evidence for the presence of a supermassive black hole in an active galaxy. Theorists believe that in galactic masers coherent microwaves are produced and amplified within gas clouds; the energy supply would come from a nearby black hole. The new maser is ten times more powerful than any previous specimen. Furthermore, the astronomers at the Max Planck Institute (Germany) who discovered the new water-vapor giga-maser believe that it hints at the existence of yet more powerful masers at higher red shifts and that the study of such distant objects may facilitate an alternative measurement of the Hubble constant. (Koekemoer et al., Nature, 14 December 1995.)