Who devised a new way for calculating the orbits of comets?

   German astronomer and physician Heinrich Wilhelm Matthaus Olbers (1758-1840) was a man of amazing energy and intellect. He was respected equally in both the med­ical and astronomical communities. As a physician, he was praised for his vaccination campaigns and for heroically treating people during several epidemics of cholera. As an astronomer, Olbers was best known for his discovery of five comets and for devising a new method of calculating their orbits. He discovered his first comet in 1780, at the age of twenty-two. The next year Olbers established his medical practice in Bremen and quickly drew a large clientele. He also set up an observatory in the second floor of his house, where he pointed telescopes out of two large bay Windows. He acquired a number of high-quality instruments and an extensive astronomical library. By the time of Olbers's death, his library held 4,361 items and was considered one of the best private collections in Europe.

   Olbers published a work in 1797 that gained him a reputation as one of the leading astronomers of the time. This publication was based on a comet Olbers had discov­ered the previous year, for which he devised a new way of calculating its orbit. Olbers's method proved more accurate and easier to use than the cumbersome set of equations developed a few years earlier by French astronomer Fierre Simon Laplace. While the pursuit of comets remained Olbers's primary astronomical interest, he also was one of the first discoverers of asteroids. Ceres, the first asteroid, was discovered on New Year's day 1801 by Italian monk Giuseppe Piazzi. While following the path of Ceres, Olbers discovered a second asteroid, Pallas, in March 1802. He found a third asteroid, Vesta, in March 1807. After that Olbers returned to comet hunting. By the end of his life he had found four new comets and calculated the orbits of eighteen others. Olbers also hypothesized, correctly, that matter ejected by a comet's nucleus is swept back into a tail by the force of the Sun.