In the second half of the 19th century Wilhelm Tempel (1821-1889) ranked among the most popular research scientists because of his many discoveries in astronomy. (Prof. Dr. Dieter B. Herrmann, astronomy historian, Berlin)
Tempel explored five Minor Planets, 21 Comets and numerous cosmic nebulas. The most well-know is maybe the comet Tempel-Tuttle, which disintegration products cause the meteor stream of the Leonids (November shooting stars). And also the planned flight of a sonde (NASA) to the comet Tempel 1 in 2004/05 promises to become very interesting.
Illustration: W. Tempel 1868 and his private telescope