Giacomo F. Maraldi

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