Maarten Schmidt

Maarten Schmidt


Date of Birth
December 28, 1929
Date of Death
September 17, 2022

A native of Groningen, Maarten Schmidt earned his bachelor's degree at the University of Groningen. While a graduate student at Leiden University, he spent a year operating an observatory and measuring stellar positions for the second Leiden expedition in Kenya. He returned to Leiden to participate in the first radio survey of the northern sky, using the 21-cm line to measure radial velocities of hydrogen clouds and thus map out the spiral arms in half of the Galaxy. He earned his Ph.D. in 1956 under Jan H. Oort with a thesis on the mass distribution in the Galaxy as determined from rotation curves obtained from 21-cm observations. He spent the next two years as a Carnegie Fellow at the Mt. Wilson and Palomar Observatories, returned to Leiden for one year, and then joined the faculty of the California Institute of Technology, where he stayed for the rest of his life. He formally retired in 1996 but continued publishing research for more than a decade. At first he continued working on the mass distribution and dynamics of the Galaxy, including the exchange of matter between stars and gas clouds. When Rudolph Minkowski retired, Schmidt took over his project of taking spectra of objects which had been found to be radio emitters. In 1963 he identified the first quasar, showing that these starlike objects exhibit ordinary hydrogen lines, but at redshifts far greater than those observed in stars. After that he  investigated the evolution and distribution of quasars, discovering that they were more abundant when the universe was younger, one of the major reasons for the decline in favor of steady state models of the universe. He and his colleagues found that the abundance of quasars was a maximum at an early time (a redshift of about 2.5), and that they were less abundant at very early times, and he long sought to find the redshift above which there are no quasars. In later years he joined teams finding x-ray and gamma ray sources from orbiting observatories such as ROSAT and the Compton Gamma Ray Observatory. He then obtained their optical spectra at the Keck Observatory. He spent several years as an administrator at Caltech, heading astronomy from 1972-75 and the physics, mathematics and astronomy division for the next three years. From 1978-80 he served as the last director of the Hale Observatories before initiating the divorce of Caltech and its Palomar Observatory from the Carnegie Institution of Washington and its Mount Wilson Observatory.

Presentation of Bruce medal

Cowley, Anne, Mercury 21, 6, 197-198 (1992).

Other awards

American Academy of Arts & Sciences, Rumford prize, 1968.
American Astronomical Society, Helen B. Warner Prize, 1964; Henry Norris Russell Lectureship, 1978.
Astronomische Gesellschaft, Karl Schwarzschild Medal, 1968.
Kavli Foundation, Kavli Prize for Astrophysics, 2008
National Academy of Sciences, James Craig Watson Medal, 1991.
National Radio Astronomy Observatory, Jansky Lectureship, 1979.
Royal Astronomical Society, Gold medal, 1980.

Some offices held

American Astronomical Society, President, 1984-86.

Biographical materials

New Netherlands Institute
Schmidt, Maarten, interview with Alan Lightman, in Lightman, Alan & Roberta Brawer, Origins: The Lives and Worlds of Modern Cosmologists (Harvard Univ. Press, Cambridge, UK, 1990), pp. 102-19.
Schmidt, Maarten, Autobiography on  receiving the Kavli Prize, 2008
Schmidt, Maarten, “Exploring the Universe,” Ann. Rev. Astron. & Astrophys. 53, 1-14 (2015) [includes videos].


California Institute of Technology, 19 Sept 2022
Schneider, Donald P., Physics Today, 76(1), 59 (2023).

Academic genealogy



Caltech Archives [several]
AIP Center for History of Physics [several]
Time Magazine cover, 11 March 1966 [painting]

Named after him

Minor Planet #10430 Martschmidt


Papers, etc.

There are oral history interviews with Schmidt from 1975, 1977, and 1989 at the Niels Bohr Library & Archives. There are oral history interviews from 1992, 1996, and 2000 and other materials at the Caltech Archives.

Other References: Historical

Fifty Years of Quasars: A symposium in Honor of Maarten Schmidt, Caltech, 2013
includes links to talks by Schmidt and others and their slides.

Chapman, David M.F., “Reflections: Maarten Schmidt and the Discovery of Quasar Redshifts,” JRASC 97, 13 (2003).

Devorkin, David, Schmidt and 3C327 (video)

Ellis, Barbara, “Redshift Turns Gold for Maarten Schmidt,” Caltech News 42, (4), 3 (2008).

Kellermann, K.I., “The Discovery of Quasars and its Aftermath,” Journal of Astronomical History and Heritage 17, 267-82 (2014).

Preston, Richard, First Light: The Search for the Edge of the Universe (Atlantic Monthly Press, NY, 1987).

Preston, Richard, “Beacons in Time — Maarten Schmidt and the Discovery of Quasars,” Mercury 17, 2 (1988).

Schmidt, Maarten, “Discovery of Quasars,” in K. Kellermann & B. Sheets, eds., Serendipitous Discoveries in Radio Astronomy: Proceedings of a Workshop Held at the National Radio Astronomy Observatory, Green Bank, West Virginia on May 4, 5, 6 1983 (NRAO, Green Bank, WV, 1984), pp. 171-74.

Schmidt, Maarten, “The Discovery of Quasars,“ in B. Bertotti, et al, eds., Modern Cosmology in Retrospect (Cambridge Univ. Press, Cambridge, UK, 1990), pp. 347-54.

Trimble, V., R. Blandford, R. Green, I.N. Reid, & M. Schmidt, “Conference report — Astronomical Luminosity Functions: A Celebration for Maarten Schmidt,” Comments on Astrophys.18, 119-137 (1995).

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Other References: Scientific

Oort, J.H. & M. Schmidt, “Differences between New and Old Comets,” Bull. Astr. Inst. Netherlands 11, 259-70 (1950).

Schmidt, M., “Spiral Structure in the Inner Parts of the Galactic System Derived from the Hydrogen Emission at 21-cm Wavelength,” Bull. Astr Inst. Netherlands 13, 247-68 (1957).

Schmidt, Maarten, “The Rate of Star Formation,” Ap.J. 129, 243-58 (1959).

Kraft, Robert P. & Maarten Schmidt, “Galactic Structure and Galactic Rotation from Cepheids,” Ap.J. 137, 249-67 (1962).

Schmidt, M., “3C273: A Star-like Object with Large Red-shift,” Nature 197, 1040 (1963) [excerpted with commentary and related papers in Lang, Kenneth R. & Owen Gingerich, eds., A Source Book in Astronomy & Astrophysics, 1900-1975 Harvard Univ. Press, Cambridge, MA, 1979), 803-10].

Greenstein, Jesse L. & Maarten Schmidt, “The Quasi-Stellar Radio Sources 3C 48 and 3C 273,” Ap.J. 140, 1-34 (1964) [excerpted with commentary in Lang, Kenneth R. & Owen Gingerich, eds., A Source Book in Astronomy & Astrophysics, 1900-1975 Harvard Univ. Press, Cambridge, MA, 1979), 811-18].

Matthews, Thomas A., William W. Morgan, & Maarten Schmidt, “A Discussion of Galaxies Identified with Radio Sources,” Ap.J. 140, 35-66 (1964).

Blaauw, Adriaan & Maarten Schmidt, Galactic Structure (Univ. of Chicago Press, Chicago, 1965).

Schmidt, Maarten, “Quasi-stellar sources,” Mitteilungen der Astronomischen Gesellschaft 25, 13-17 (1968) [Karl Schwarzschild lecture].

Bahcall, John N., Maarten Schmidt, & James E. Gunn, “Are Some Quasi-Stellar Objects Associated with Clusters of Galaxies?” Ap.J. 157, 77 (1969).

Schmidt, Maarten, “Quasistellar Objects,” Ann. Rev. Astron. & Astrophys. 7, 527-52 (1969).

Schmidt, Maarten, “Quasars and Cosmology” (1971 Halley Lecture), Observatory 91, 209-14 (1971).

Richstone, Douglas O. & Maarten Schmidt, “The Spectral Properties of a Large Sample of Quasars,” Ap.J. 235, 361-76 (1980).

Green, Richard F., et al, “Observations of Quasars with the International Ultraviolet Explorer Satellite,” Ap.J. 239, 483-94 (1980).

Schmidt, Maarten & Richard F. Green, “Quasar Evolution Derived from the Palomar Bright Quasar Survey and Other Complete Quasar Surveys,” Ap.J. 269, 352-74 (1983).

Tananbaum, H., et al, “X-ray Observations of the Bright Quasar Survey,” Ap.J. 305, 57-67, 310, 518-33 (1986).

Schmidt, Maarten, Donald P. Schneider, & James E. Gunn, “Spectroscopic CCD Surveys for Quasars at Large Redshift. A Deep PFUEI survey,” Ap.J. 306, 411-27 (1986).

Kellermann, K.I., et al, “VLA Observations of Objects in the Palomar Bright Quasar Survey,” Astronomical Journal 98, 1195-1207 (1989).

Schmidt, Maarten, Donald P. Schneider, & James E. Gunn, “Luminosity Function of Quasars at Large Redshifts from GRISM Surveys,” The Space Distribution of Quasars, ASP Conference Series 21 (1991), 109-16.

Kellermann, K.I., et al, “The Radio Structure of Radio Loud and Radio Quiet Quasars in the Palomar Bright Quasar Survey,” Astronomical Journal 108, 1163-77 (1994).

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Other Works: Popularizations, Fiction, etc.

Schmidt, Maarten & Francis Bello, “The Evolution of Quasars,” Sci. Am., May 1971, pp. 55-69.

50-Year Cosmic Mystery: 10 Quasar Questions for Discoverer Maarten Schmidt,