Eugene Newman Parker (June 10, 1927 – March 15, 2022) was an American solar and plasma physicist. In the 1950s he proposed the existence of the

solar wind The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the sol ...

and that the magnetic field in the

outer Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

would be in the shape of a

Parker spiral The heliospheric current sheet, or interplanetary current sheet, is a surface separating regions of the heliosphere where the interplanetary magnetic field points toward and away from the Sun. A small electrical current with a current density of ...

, predictions that were later confirmed by spacecraft measurements. In 1987, Parker proposed the existence of

nanoflare A nanoflare is a very small episodic heating event which happens in the corona, the external atmosphere of the Sun. The hypothesis of small impulsive heating events as a possible explanation of the coronal heating was first suggested by Thom ...

s, a leading candidate to explain the

coronal heating problem A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma. The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total so ...

. Parker obtained his PhD from

Caltech The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

and spent four years as a

postdoctoral researcher A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). The ultimate goal of a postdoctoral research position is to pu ...

at the

University of Utah The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of De ...

. He joined

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private university, private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park, Chicago, Hyde Park neighborhood. The University of Chic ...

in 1955 and spent the rest of his career there, holding positions in the physics department, the

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

and astrophysics department, and the

Enrico Fermi Institute __NOTOC__ The Institute for Nuclear Studies was founded September 1945 as part of the University of Chicago with Samuel King Allison as director. On November 20, 1955, it was renamed The Enrico Fermi Institute for Nuclear Studies. The name was s ...

. Parker was elected to the National Academy of Sciences in 1967. In 2017,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

named its

Parker Solar Probe The Parker Solar Probe (PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+) is a NASA space probe launched in 2018 with the mission of making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii ...

in his honor, the first NASA spacecraft named after a living person.

Biography

Parker was born in Houghton, Michigan to Glenn and Helen (MacNair) Parker on June 10, 1927. He received his

Bachelor of Science A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University o ...

degree in

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

from Michigan State University in 1948 and a

Doctor of Philosophy A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

from Caltech in 1951. Parker spent four years at the

before joining the University of Chicago in 1955, where he spent the rest of his career. He held positions in Chicago's physics department,

and astrophysics department, and the

. Parker was elected to the National Academy of Sciences in 1967.

Hypotheses

In the mid-1950s, Parker developed the theory of the supersonic

and predicted the

shape of the solar magnetic field in the

. His theoretical modeling was not immediately accepted by the astronomical community: when he submitted the results to ''

The Astrophysical Journal ''The Astrophysical Journal'', often abbreviated ''ApJ'' (pronounced "ap jay") in references and speech, is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and ...

'', two reviewers recommended its rejection. The editor of the journal, Subrahmanyan Chandrasekhar, overruled the reviewers and published the paper anyway. Parker's theoretical predictions were confirmed by satellite observations a few years later, especially the 1962

Mariner 2 Mariner 2 (Mariner-Venus 1962), an American space probe to Venus, was the first robotic space probe to conduct a successful planetary encounter. The first successful spacecraft in the NASA Mariner program, it was a simplified version of the B ...

mission. Parker's work increased understanding of the

solar corona A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma. The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar ...

, the

, the magnetic fields of both the Earth and the Sun, and their complex electromagnetic interactions. He published several

textbook A textbook is a book containing a comprehensive compilation of content in a branch of study with the intention of explaining it. Textbooks are produced to meet the needs of educators, usually at educational institutions. Schoolbooks are textbook ...

s, including ''Cosmical Magnetic Fields'' in 1979, and one on magnetic fields in X-ray astronomy in 1994. Seeking to address the

, in 1987 Parker proposed that the solar corona might be heated by myriad tiny "

s", miniature brightenings resembling

solar flare A solar flare is an intense localized eruption of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other sol ...

s that would occur all over the surface of the Sun. Parker's theory became a leading candidate to explain the problem.

Personal life

Parker was married to his wife, Niesje, for 67 years, with whom he had two children. He died in Chicago on March 15, 2022, at the age of 94.

Honors and awards

* 1969: Arctowski Medal of the National Academy of Sciences * 1969: Henry Norris Russell Lectureship of the American Astronomical Society * 1978:

George Ellery Hale Prize The George Ellery Hale Prize, or Hale Prize, is awarded annually by the Solar Physics Division of the American Astronomical Society for outstanding contributions over an extended period of time to the field of solar astronomy. The prize is named in ...

, Solar Physics Division of the American Astronomical Society, first time this prize was awarded *1979: Chapman Medal, Royal Astronomical Society * 1989:

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social scienc ...

* 1990:

William Bowie Medal The William Bowie Medal is awarded annually by the American Geophysical Union for "outstanding contributions to fundamental geophysics and for unselfish cooperation in research". The award is the highest honor given by the AGU and is named in honor ...

* 1992:

Gold Medal of the Royal Astronomical Society The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...

* 1997:

Bruce Medal The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was fi ...

* 2003:

Kyoto Prize The is Japan's highest private award for lifetime achievement in the arts and sciences. It is given not only to those that are top representatives of their own respective fields, but to "those who have contributed significantly to the scientific, ...

* 2003: James Clerk Maxwell Prize of the American Physical Society. Citation: "For seminal contributions in

plasma astrophysics Astrophysical plasma is plasma outside of the Solar System. It is studied as part of astrophysics and is commonly observed in space. The accepted view of scientists is that much of the baryonic matter in the universe exists in this state. When ...

, including predicting the

, explaining the

solar dynamo The solar dynamo is a physical process that generates the Sun's magnetic field. It is explained with a variant of the dynamo theory. A naturally occurring electric generator in the Sun's interior produces electric currents and a magnetic field ...

, formulating the theory of

magnetic reconnection Magnetic reconnection is a physical process occurring in highly conducting plasmas in which the magnetic topology is rearranged and magnetic energy is converted to kinetic energy, thermal energy, and particle acceleration. Magnetic reconnecti ...

, and the

instability In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds. Not all systems that are not stable are unstable; systems can also be mar ...

which predicts the escape of the magnetic fields from the galaxy." * 2010: Member of the

Norwegian Academy of Science and Letters The Norwegian Academy of Science and Letters ( no, Det Norske Videnskaps-Akademi, DNVA) is a learned society based in Oslo, Norway. Its purpose is to support the advancement of science and scholarship in Norway. History The Royal Frederick Unive ...

. * 2017:

renamed its ''Solar Probe Plus'' to ''

'' after Parker, the first time that a space vessel was named after a living person. Parker was present at its August 12, 2018, launch. * 2018: Medal for Exceptional Achievement in Research of the American Physical Society. Citation: "For fundamental contributions to space physics, plasma physics, solar physics and astrophysics for over 60 years." * 2020:

Crafoord Prize The Crafoord Prize is an annual science prize established in 1980 by Holger Crafoord, a Swedish industrialist, and his wife Anna-Greta Crafoord. The Prize is awarded in partnership between the Royal Swedish Academy of Sciences and the Crafoord Foun ...

in Astronomy

Books

* ''Cosmical Magnetic Fields: Their Origin and their Activity'', 1979, Oxford University Press. . * ''Spontaneous Current Sheets in Magnetic Fields: With Applications to Stellar X-rays'', 1994, Oxford University Press. . * ''Conversations on Electric and Magnetic Fields in the Cosmos'', 2007, Princeton University Press. .

References

{{DEFAULTSORT:Parker, Eugene 1927 births 2022 deaths 20th-century American astronomers 21st-century American astronomers American astrophysicists American plasma physicists Fellows of the American Physical Society Fellows of the Royal Astronomical Society Foreign Fellows of the Royal Astronomical Society Kyoto laureates in Basic Sciences Members of the Norwegian Academy of Science and Letters Members of the United States National Academy of Sciences Michigan State University alumni National Medal of Science laureates People from Houghton, Michigan Recipients of the Gold Medal of the Royal Astronomical Society Scientists from Michigan University of Chicago faculty University of Utah faculty Writers from Michigan