Rotation of venus: continuing contradictions

Abstract

Optical observations of Venus have yielded various values of the rotation period extending from less than one to several hundred days. Radar observations give a retrograde rotation of the solid globe in 244 +/- 2 days. Recent ultraviolet photographs, however, show relatively rapid displacements of clouds in the high atmosphere of Venus which suggest a retrogrode rotation in only 5 days. The two rates seem to be physically incompatible.