Born in France in 1732, Jerome de Lalande initially planned to pursue law. But while studying in Paris, he was drawn to the lectures at the observatory of Joseph-Nicolas Delisle, and quickly began assisting there. When he finished his law degree, he traveled to Berlin to measure the parallax of the Moon and Mars; after his return to Paris, he was elected to the Academie des Sciences. He would go on to a fruitful astronomical career, predicting the timing for the return of Halley’s Comet, coordinating observations of the transit of Venus in 1761 and 1769, becoming known for the precision of his observations and measurements. With his family assisting, he compiled a catalog of over 47,000 stars (Historie celeste francaise, 1801), as well as several other almanacs and textbooks.
Lalande was a professor of astronomy for 46 years at the College Royale (College de France), and served as the director of the Paris Observatory. He was a mentor for students there as well as an advocate for women in science, admitting women to all classes at the College Royale and collaborating with his female relatives on calculations and research. He died on April 4, 1807, likely of tuberculosis.
