Urbain Le Verrier was a French mathematician and astronomer born on March 11, 1811. He is best known for his work in celestial mechanics, particularly for predicting the existence of the planet Neptune. Using mathematical calculations, he was able to determine Neptune's position in the sky before it was observed through a telescope. Le Verrier's predictions were confirmed in 1846 when Johann Galle and Heinrich d'Arrest discovered Neptune based on his calculations. His contributions significantly advanced the field of astronomy and demonstrated the power of mathematics in understanding celestial bodies. Le Verrier also worked on the orbits of other planets and contributed to the study of Mercury.