| Blast from the past.Since 1994, when comet Shoemaker-Levy plunged to its spectacular demise on Jupiter, astronomers have been curious as to whether any records exist of such impacts in the past. A Yokohama engineer and amateur astronomer, Isshi Tabe, hit pay dirt while digging through old manuscripts in the library of the Paris Observatory. The drawing below was made by the famous 17th century astronomer Giovanni-Dominique Cassini, who recorded how a spot on Jupiter - much like the dark bruises Shoemaker-Levy left on its gassy surface - varied over 18 days following its appearance on 5 December 1690. "I was really surprised," says Tabe, who says he didn't think such detailed drawings were done before the 1800s. Junichi Watanabe, public information officer at Japan's National Astronomical Observatory in Tokyo, says "The variation over time looked very much like of Shoemaker-Levy 9. It was really exciting." A letter on the find will appear next month in Publications of the Astronomical Society of Japan. |
