Audouin DollfusBorn 12 Nov 1924.French astronomer who was the successor to Bernard Lyot as the principal French authority on the solar system. Dollfus made several balloon flights for high-altitude observations, including the first stratospheric ascension in France. On the basis of comparative light-polarizing qualities, he concluded that the surface material of Mars consists of pulverized limonite (an iron oxide, Fe2O3) and prepared a map of Venus showing what he believed to be permanent features. On 15 Dec 1966, he discovered Saturn's tenth known satellite, Janus. Subsequently lost, it is now accepted to be satellite 1980S1 orbiting Saturn in an almost circular orbit of radius 151,472 km in a period of 0.69433 days. A small satellite of diameter no more than 220 km, Janus is a co-orbital satellite with Epimetheus. |
