Milton La Salle Humason (August 19, 1891 – June 18, 1972) 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 ...

. He was born in Dodge Center,

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

Biography

Humason dropped out of school and had no formal education past the age of 14. Because he loved the mountains, and Mount Wilson in particular, he became a "mule skinner" taking materials and equipment up the mountain while

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 ...

was being built. In 1917, after a short stint on a ranch in La Verne, he became a

janitor A janitor (American English, Scottish English), also known as a custodian, porter, cleanser, cleaner or caretaker, is a person who cleans and maintains buildings. In some cases, they will also carry out maintenance and security duties. A simil ...

at the observatory. Out of sheer interest, he volunteered to be a night assistant at the observatory. His technical skill and quiet manner made him a favorite on the mountain. Recognizing his talent, in 1919,

George Ellery Hale George Ellery Hale (June 29, 1868 – February 21, 1938) was an American solar astronomer, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-lea ...

made him a Mt. Wilson staff member. This was unprecedented, as Humason did not have a Ph.D., or even a high school diploma. He soon proved Hale's judgment correct, as he made several key observational discoveries. He became known as a meticulous observer, obtaining photographs and difficult

spectrogram A spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time. When applied to an audio signal, spectrograms are sometimes called sonographs, voiceprints, or voicegrams. When the data are represen ...

s of faint galaxies. His observations played a major role in the development of

physical cosmology Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of f ...

, including assisting

Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an Americans, American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects ...

in formulating

Hubble's law Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are, the faster they are moving ...

. In 1950 he earned a D.Sc. from

Lund University , motto = Ad utrumque , mottoeng = Prepared for both , established = , type = Public research university , budget = SEK 9 billion C/1961 R1 Comet Humason, formally designated C/1961 R1 (a.k.a. 1962 VIII and 1961e), was a non-periodic comet discovered by Milton L. Humason on September 1, 1961. Its perihelion was well beyond the orbit of Mars, at 2.133 AU. The outbound orbital peri ...

(Humason), notable for its large

perihelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

distance. Due to merest chance, Humason missed discovering

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

. Eleven years before

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 ...

, Humason took a set of four photographs in which the image of Pluto appeared. There is persistent speculation that he missed discovering the dwarf planet because it fell on a defect in the photographic plate. This is unlikely, however, given that it appeared in four separate photographs over three different nights. Much of the work Humason performed was actually credited to Hubble, the two of whom worked together for many years. He died in

Mendocino, California Mendocino (Spanish for "of Mendoza") is an unincorporated community and census-designated place (CDP) in Mendocino County, California, United States. Mendocino is located south of Fort Bragg at an elevation of . The population of the CDP was 932 ...

In popular culture

In the popular documentary '' Cosmos: A Personal Voyage'' by astronomer

Carl Sagan Carl Edward Sagan (; ; November 9, 1934December 20, 1996) was an American astronomer, planetary scientist, cosmologist, astrophysicist, astrobiologist, author, and science communicator. His best known scientific contribution is research on ext ...

, Humason's life and work are portrayed on screen in episode 10: ''The Edge of Forever.'' Humason was also the inspiration for the

Big Dipper The Big Dipper ( US, Canada) or the Plough ( UK, Ireland) is a large asterism consisting of seven bright stars of the constellation Ursa Major; six of them are of second magnitude and one, Megrez (δ), of third magnitude. Four define a "bowl" ...

song "Humason," which appeared on the Boston group's 1987 album Heavens.

Honors

* The crater

Humason Milton La Salle Humason (August 19, 1891 – June 18, 1972) was an American astronomer. He was born in Dodge Center, Minnesota. Biography Humason dropped out of school and had no formal education past the age of 14. Because he loved the m ...

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 ...

is named after him as are " Humason-Zwicky stars".

Cited sources

External links

Obituary

{{DEFAULTSORT:Humason, Milton 1891 births 1972 deaths People from Dodge Center, Minnesota 20th-century American astronomers Discoverers of comets