Maurice (Moritz) Loewy (April 15, 1833 – October 15, 1907) was a French astronomer.

Born in Mariánské Lázne , in what is now the Czech Republic, Loewy's Jewish parents moved to Vienna in 1841 to escape the antisemitism of their home town. Loewy became an assistant at the Vienna Observatory , working on celestial mechanics. However, the institutions of Austria-Hungary did not permit a Jew to advance to a senior position without renouncing their faith and embracing Catholicism. The director of the observatory Karl L. Littrow was a correspondent of Urbain Le Verrier, director of the Paris Observatory and he secured a position there for Loewy in 1860, Loewy going on to become a naturalised French citizen.

He worked on the orbits of asteroids and comets and on the measurement of longitude, improving the accuracy of the Connaissance des Temps . He also worked on optics and the elimination of the aberration of light.

He was elected a member of the Bureau des Longitudes in 1872 and of the Académie des Sciences in 1873.

Loewy became director of the Paris Observatory in 1896, reorganising the institution and establishing a department of physical astronomy. He further spent a decade working with Pierre Puiseux on an atlas of the Moon composed of 10,000 photographs, L’Atlas photographique de la Lune (1910), the definitive basis for lunar geography for over half a century. A crater on the Moon is named after him and asteroid 253 Mathilde is believed to be named after his wife.

He died in Paris at a government meeting of a sudden and unanticipated cardiac arrest.

Honours

• Gold Medal of the Royal Astronomical Society, (1889)