... and unexpected event and only powerful USSR-like radar can provide comprehensive scientific information about cometary nucleus and coma, because of impossibility to install and direct dedicated space probe towards this comet for such short (~ year) time ...
... R. F., Winkler R., Yeomans D. K., Choate D., Cormier R., Giorgini J. D., Mitchell D. L., Chodas P. W., Rose R., Kelley D., Slade M. A., Thomas M. L. "Radar Detection of the Nucleus and Coma of Comet Hyakutake (C/1996 B2)", Science, 278 , 1921-1924, 1997 ...