On this date in 1695, Christian Huygens, the man who discovered Saturn's largest moon, Titan, died at the age of 66. A leading scientist of his time, Huygens made scientific contributions in the areas of what. In terms of astronomy, Huygens invented a 50 power refracting telescope, which he then used to discover the first moon of Saturn, Titan, and complete the most detailed examination of Saturn's rings up to that time, becoming the first man to suggest that Saturn was, in fact, surrounded by a ring at all. In addition, Huygens is noted for his making of the first drawing of the Orion Nebula and for his discovery of several nebulae and binary stars.
Additionally, shortly before his death, Huygens wrote Cosmotheros, in which he made arguments for the existence of alien life and proposed a system for determining stellar distances based upon the star Sirius. In fact, if Sirius were as intrinsically bright as the Sun (which it is not), Huygens' estimates would have been very close.