William Henry Pickering (February 15, 1858 – January 16, 1938) was an American

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

. Pickering constructed and established several

observatories An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. His ...

or astronomical observation stations, notably including

Percival Lowell Percival Lowell (; March 13, 1855 – November 12, 1916) was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars, and furthered theories of a ninth planet within the Solar System. ...

's Flagstaff Observatory. He led

solar eclipse A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of the Earth, totally or partially. Such an alignment occurs during an eclipse season, approximately every six month ...

expeditions and studied craters on the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

, and hypothesized that changes in the appearance of the crater Eratosthenes were due to "lunar insects". He spent much of the later part of his life at his private observatory in

Jamaica Jamaica (; ) is an island country situated in the Caribbean Sea. Spanning in area, it is the third-largest island of the Greater Antilles and the Caribbean (after Cuba and Hispaniola). Jamaica lies about south of Cuba, and west of His ...

Biography

William Pickering was born on February 15, 1858 in Boston, Massachusetts. His older brother was

Edward Charles Pickering Edward Charles Pickering (July 19, 1846 – February 3, 1919) was an American astronomer and physicist and the older brother of William Henry Pickering. Along with Carl Vogel, Pickering discovered the first spectroscopic binary stars. He wrote ' ...

, director of the

Harvard College Observatory The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, United St ...

for three decades. He graduated from the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

in 1879 then became an instructor in physics from 1880 to 1887. He was elected a Fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

in 1883 at age 25. He discovered

Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...

's ninth

moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

Phoebe in 1899 from plates taken in 1898. He produced a photographic atlas of the Moon: ''The Moon : A Summary of the Existing Knowledge of our Satellite'' in 1903. He believed he discovered a tenth Saturnian moon in 1905 from plates taken in 1904, which he called "

Themis In Greek mythology and religion, Themis (; grc, Θέμις, Themis, justice, law, custom) is one of the twelve Titan children of Gaia and Uranus, and the second wife of Zeus. She is the goddess and personification of justice, divine order, fai ...

". For this discovery he was awarded the

Lalande Prize The Lalande Prize (French: ''Prix Lalande'' also known as Lalande Medal) was an award for scientific advances in astronomy, given from 1802 until 1970 by the French Academy of Sciences. The prize was endowed by astronomer Jérôme Lalande in 180 ...

of the French Academy of Sciences in 1905. "Themis" was later shown to not exist. Following

George Darwin Sir George Howard Darwin, (9 July 1845 – 7 December 1912) was an English barrister and astronomer, the second son and fifth child of Charles Darwin and Emma Darwin. Biography George H. Darwin was born at Down House, Kent, the fifth chi ...

, he speculated in 1907 that the Moon was once a part of the Earth and that it broke away where now the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

lies. He also proposed a version of

continental drift Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The idea of continental drift has been subsumed into the science of pla ...

before

Alfred Wegener Alfred Lothar Wegener (; ; 1 November 1880 – November 1930) was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher. During his lifetime he was primarily known for his achievements in meteorology and ...

where America,

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

, and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

once formed a single continent, which broke up because of the separation of the Moon. In 1908 he made a statement regarding the possibility of airplanes that had not yet been invented, saying that "a popular fantasy is to suppose that flying machines could be used to drop dynamite on the enemy in time of war". In 1919, he predicted the existence and position of a

Planet X Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and continued at the start of the 20th with Percival Lowell's ...

based on anomalies in the positions of

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus ( Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars), grandfather of Zeus (Jupiter) and father of ...

and

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

but a search of

Mount Wilson Observatory The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observat ...

photographs failed to find the predicted planet.

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest ...

was later discovered at Flagstaff by

Clyde Tombaugh Clyde William Tombaugh (February 4, 1906 January 17, 1997) was an American astronomer. He discovered Pluto in 1930, the first object to be discovered in what would later be identified as the Kuiper belt. At the time of discovery, Pluto was cons ...

in 1930, but in any case it is now known that Pluto's mass is far too small to have appreciable gravitational effects on Uranus or Neptune, and the anomalies are accounted for when today's much more accurate values of planetary masses are used in calculating orbits. When the planet was named, he interpreted its symbol as a monogram referring to himself and Lowell by the phrase "Pickering-Lowell". He claimed to have found vegetation on the Moon in 1921. In 1923 he retired from

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

. He died on January 16, 1938 in

Mandeville, Jamaica Mandeville is the capital and largest town in the parish of Manchester in the county of Middlesex, Jamaica. In 2005, the town had an estimated population of 50,000, and including the immediate suburbs within a radius of the total population w ...

Awards

He won the Prix Lalande in 1905 and the Prix Jules Janssen in 1909. The asteroid

784 Pickeringia 784 Pickeringia ('' prov. designation:'' ''or'' ) is a large background asteroid, approximately in diameter, located in the outer region of the asteroid belt. It was discovered on 20 March 1914, by American astronomer Joel Hastings Metcalf at ...

, and the craters Pickering on the

and Pickering on Mars, are jointly named after him and his brother

References

External links

William H. Pickering Papers, 1892–1893
from the

Smithsonian Institution Archives Smithsonian Libraries and Archives is an institutional archives and library system comprising 21 branch libraries serving the various Smithsonian Institution museums and research centers. The Libraries and Archives serve Smithsonian Institution ...

;Obituaries
JRASC 32 (1938) 157
(one paragraph)

PA 46 (1938) 299
{{DEFAULTSORT:Pickering, William Henry 1858 births 1938 deaths American astronomers Discoverers of moons Fellows of the American Academy of Arts and Sciences Harvard University faculty Massachusetts Institute of Technology alumni Massachusetts Institute of Technology School of Science faculty Recipients of the Lalande Prize Scientists from Boston