William Henry Pickering , born with Boston the 15 February 1858 and died in Mandeville (Jamaica) the January 17th 1938, is a American Astronome , the brother of another famous astronomer, Edward Charles Pickering.

He discovered the ninth Natural satellite of Saturn, Phœbé, in 1899, starting from photographic plates taken in 1898. He also thought of having discovered the tenth moon for this same planet in 1905, that he called THEMIS, but this satellite since remained untraceable, being probably an error of observation, dependant on atmospheric disturbances. Pickering accepted the Prix Lalande of the Academy of Science in 1906 for its “discovery of the ninth and tenth Saturn satellites”.

It led several forwardings intended for the observation of the eclipse S solar, and intensively studied the craters of impact on the the Moon. It contributed intensively to the installation new astronomical observatories, in particular the Observatoire Lowell with Flagstaff.

In 1919, it predicts the existence and the position of a new planet, named Planet X, while being based on the anomalies measured in the Orbite S of Uranus and Neptune, but the research led to the Observatoire of the Mount Wilson did not bring any result. Pluton was discovered in 1930 by Clyde Tombaugh in Flagstaff, but we know today that the mass of Pluto is too much low to be able to generate observable effects on the movements of Uranus and Neptune.

It passed most of the end of its life in its observatory deprived in Jamaica, and published an atlas of the Moon: The Moon: In Summary off the Satellite Existing Knowledge off our - New York: Doubleday, Page & Company, 1903.

The Pickering crater , a lunar crater, bears its name to pay homage to him, like with his/her brother.