Variable Features on Mars: Mariner 9 Observations of Promethei Sinus Sagan, C. ; Veverka, J. ; Fox, P. ; French, R. ; Dubisch, R. ; Gierasch, P. ; Quam, L. ; Lederberg, J. ; Levinthal, E. ; Tucker, R. ; Eross, B. ; Pollack, J. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: March 1973 Bibcode: 1973BAAS....5S.295S