Observations at Yale of planetary nonthermal noise were first made in 1957 from March to June at 21.1 Mc/s by a single close-spaced phase-switching interferometer with Yagi elements. To be accepted as possibly planetary, noise events had to be unidentifiable as terrestrial; they had to fit the interferometer pattern; and they had to occur when the planet was in the Yagi beams. Thirteen events satisfied these criteria for Jupiter (Fig. 1a), giving the rotation histogram Fig. 2a when plotted according to the System III period of Carr et al. [1]. The pattern is quite similar to that obtained for the immediately preceding months by the Florida group (Fig. 2b).