Asaph Hall

Asaph Hall (* October 15, 1829 in Goshen, Connecticut, † November 22, 1907 in Annapolis, Maryland) was an American astronomer and is the discoverer of the two Martian moons Phobos and Deimos.

After the death of his parents, Hall took on an apprenticeship as a carpenter and then attended the University of Michigan, where he studied astronomy. Lack of money, he was forced to leave the university and in 1857 to accept a position at the Harvard College Observatory in Cambridge. There he became an expert in calculating orbits. In August 1862 Hall moved to the United States Naval Observatory in Washington, DC, where he remained until 1891. He was professor of mathematics in 1863.

1877 was the Mars unusually favorable for the observational astronomers turned their attention to the red planet world. This led on the one hand to the discovery of the " canals of Mars " by Giovanni Schiaparelli and on the other hand to the discovery of the two moons of Mars, Phobos and Deimos by Hall. Here he was very actively supported by his wife Chloe Angeline Stickney Hall, who encouraged him repeatedly to further observations. Hall used to the large 26- inch refractor "Great Equatorial ", which at the time largest instrument of its kind in the world. Hall also calculated the orbits of the two moons. He and his wife had four children.

Asaph Hall in 1879 was awarded the Gold Medal of the Royal Astronomical Society of Great Britain. 1891 Hall left Washington and went to Annapolis, where he died in 1907.

The lunar crater Hall and the asteroid ( 2023) Asaph are named after him.