No. 33: May-Jun 1984
When the periodic comet Kopff was photographed on August 13, 1983, using the 4-meter Mayall reflector at Kitt Peak, the black-and-white photo showed nothing out-of-the-ordinary. But digitization and computer enhancement revealed a previously unnoticed cloud of matter -million miles long trailing the nucleus. Curiously, the cloud resembled a huge smoke ring -- a distinct departure from the long, flowing tails shown in the textbooks.
(Anonymous; "The Unusual Dust Cloud of Comet Kopff," Sky and Telescope, 67:226, 1984.)
Comment. Obviously forces other than the solar wind were at work here.