It is with sadness that we report the demise of RASC Honorary Member and distinguished planetary scientist, Audouin Dollfus. He was 85.

Dollfus was known for his important polarimetric and reflectance studies of solar system objects. These included among other results the successful determination of the iron oxide nature of much of the Martian regolith. On 1966 December 15 he discovered one of the inner Saturnian moons (Saturn X). He conducted highly-technical astronomical observations from innovative aerostatic balloons in the mid '50s. A master of studies involving electronic detectors, some of which he designed and made himself, interestingly Dollfus did not neglect scientific visual observation, and indeed he was a very gifted and accurate planetary artist.

Dollfus' many contributions to the history of astronomy included, not surprisingly, papers and books on the first scientific balloon flights, his mentor Bernard Lyot, his predecessor Christiaan Huygens, the development of Meudon Observatory, where he spent much of his scientific career, Arago's polarimetry, and the Pic du Midi Planetary Observation Project: 1941-1971, of which he was an important member.

He remained scientifically engaged to the end of his life. Asteroid 2451 Dollfus was named in his honour. He was a member of many distinguished scientific organizations. He was created a chevalier de la Légion d'honneur in 2009, and was a recipient of the Société Astronomique deFrance's prix Jules Janssen in 1993.

A more complete obituary will be published in the December 2010 Journal.