Giacomo F. Maraldi

Giacomo Filippo Maraldi, also known as Jacques Philippe Maraldi, was a French-Italian astronomer and mathematician, born in Perinaldo in modern Liguria on 21 August 1665 and dying on 1 December 1729. He was the nephew of Giovanni Cassini and worked for most of his life at the Paris Observatory, from 1687 to 1718. In May 1724 he recognized that the corona seen during a solar eclipse belongs to the Sun and not to the Moon, and he discovered that R Hydrae is a variable star. He also helped with the survey based on the Paris Meridian. In 1723 he confirmed the observation of his pupil Joseph-Nicolas Delisle, made in 1715, of the bright spot now called Poisson's spot, which was later recognized as convincing evidence for the wave nature of light. In mathematics he is best known for obtaining in 1712 the angle of the rhombic dodecahedron that is still called the Maraldi angle. Craters on the Moon and on Mars are named in honor of him and his nephew Jean-Dominique Maraldi.