Vocation : Science : Astronomy

Jean Abraham Chrétien Oudemans (Amsterdam, 16 December 1827 – Utrecht, 14 December 1906) was a Dutch astronomer. He was the director of the Utrecht Observatory from 1875 until 1898, when he retired.
Oudemans was born in Amsterdam, son of the poet, teacher and philologist Anthonie Oudemans Sr. and Jacoba Adriana Hammecker. He entered Leiden University when he was just 16 as a student of the noted astronomer Frederik Kaiser. He became a high school teacher in Leiden when he was just 19 (1846). The next six years he worked on his dissertation on the determination of the latitude of Leiden. Next he studied asteroids and variable stars, meanwhile hoping for an academic appointment. In 1855 he became member of the Royal Netherlands Academy of Arts and Sciences.
He married Pauline Adriana Verdam (the daughter of a well-known mathematics professor Gideon Jan Verdam ) in 1856. In the same year he was appointed a professor at Utrecht University and became the first director of its observatory. However, his interest drew him towards geography. He traveled to the Dutch East Indies as head surveyor, and worked in that capacity for 18 years, publishing his works on the triangulation of the island of Java in six books.In 1874 he organized an astronomical expedition to the island of Réunion to observe the transit of Venus but, due to bad weather, the results were disappointing.Oudemans crater on Mars was named in his honor.
A brother was the botanist Corneille Antoine Jean Abram Oudemans. One of his sons was Anthonie Cornelis Oudemans Jzn, one of the fathers of cryptozoology.

Emmett W. Chappelle (October 24, 1925 – October 14, 2019) was an American scientist who made valuable contributions in the fields of medicine, philanthropy, food science, and astrochemistry. His achievements led to his induction into the National Inventors Hall of Fame for his work on bioluminescence, in 2007. Being honored as one of the 100 most distinguished African American scientists of the 20th Century, he was also one of the members of the American Chemical Society, the American Society of Biochemistry and Molecular Biology, the American Society of Photobiology, the American Society of Microbiology, and the American Society of Black Chemists.

Albert George Wilson (July 28, 1918 – August 27, 2012) was an American astronomer and a discoverer of minor planets.He was born in Houston, Texas. He received his Ph.D. in mathematics from Caltech in 1947; his thesis title was Axially Symmetric Thermal Stresses in a Semi-Infinite Solid advised by Harry Bateman.
In 1949 he accepted a job at Palomar Observatory, and led the Palomar Sky Survey. In 1953 he became assistant director of Lowell Observatory, and served as director from 1954 to 1957. He later worked at Rand Corporation and other private sector positions. In 1962 he became founding editor of the astronomical magazine Icarus. In 1966, he accepted the position of associate director of McDonnell-Douglas Corporation Advanced Research Laboratories (DARL), which he held from 1966 until 1972. Wilson then became an adjunct professor at USC, teaching courses in philosophy and science until his retirement. After retiring Wilson was associated with the Institute on Man and Science and the Institute of the Future, lecturing and consulting for both groups.He discovered a number of asteroids, and also co-discovered the periodic comet 107P/Wilson–Harrington with Robert George Harrington. The object is also known as the minor planet 4015 Wilson–Harrington.

Harold (Hal) Masursky (December 23, 1922* – August 24, 1990) was an American astrogeologist.After leaving Yale University without defending his dissertation, he started his career in the early 1950s as a field geologist in Wyoming and Colorado working for the United States Geological Survey (USGS). In the early 1960s, he moved to the Astrogeology division of the USGS and began working at NASA's Jet Propulsion Laboratory in Pasadena, California. In the mid-1960s, he moved to Flagstaff, Arizona as a founding planetary geologist at the newly constructed USGS Astrogeology Science Center. Throughout his professional career with the USGS, his work contributed to the mission of NASA in the areas of economic, structural, and planetary geology.
He was responsible for the investigation of planetary and lunar surfaces, especially in finding scientifically valuable landing places. This included for the Apollo program, where, in the 1960s, he played a major role in choosing landing sites and assisted in training astronauts in the basics of geology so they would know what to look for on the surface of the Moon. In the 1970s, he headed the team that mapped the surface of Mars and was once again involved in choosing landing sites, this time for the Mars Viking missions. In the 1980s, he worked with the Voyager program to explore the surfaces of Jupiter, Saturn, Uranus, and Neptune.
Masursky was a strong advocate for the exploration of Venus and he was a key member of Pioneer Venus Orbiter team. He worked on numerous other space missions and programs, including, for Moon exploration, Ranger, Surveyor, the Lunar Orbiter, and the mapping of Mars by Mariner 9, as well as contributing to the missions of the Galileo and Magellan spacecraft. He was often interviewed on television as his enthusiasm for the planetary discoveries of the space missions was both edifying and infectiousAn especially key role was his work as the president of the Working Group for Planetary System Nomenclature of the International Astronomical Union (IAU). He created a small stir in 1986, when he was required to reject a popular suggestion that new moons of Uranus, discovered earlier that year, be named for the seven astronauts lost in the Space Shuttle Challenger explosion - the IAU has strict guidelines that prohibit major bodies being named in honor of persons from a particular country.In 1985, Masursky was the recipient of the Distinguished Service Award, which is the highest honorary recognition an employee can receive within the Department of the Interior. Quoting from the award, the 1985 USGS Yearbook states: “Harold Masursky, Geologist, for his imaginative leadership in the field of astrogeology which has influenced almost every facet of lunar and planetary exploration since the beginning of the nation's space program.”The Masursky crater on Mars was chosen because it is effluvial, meaning "flow" (it looks like water ran through it), to honor his fervent belief that Mars once had flowing water on the surface. In 1981, the asteroid 2685 Masursky was discovered and named in his honor. The Masursky Award for Meritorius Service to Planetary Science, first awarded to Carl Sagan in 1991, and the Masursky Lecture, originating in 1992 and given during the annual Lunar and Planetary Science Conference (LPSC), are named for him as well.
*Note there is some confusion about the year of Harold Masursky's birth; in some places it is reported as 1922 and in some places is reported as 1923.

Trịnh Xuân Thuận (born August 20, 1948) is a Vietnamese-American astrophysicist.

Charles Joseph Étienne Wolf (9 November 1827 in Vorges – 4 July 1918) was a French astronomer.
In 1862, Urbain Le Verrier offered him a post as assistant at the Paris Observatory.
In 1867 he and Georges Rayet discovered Wolf–Rayet stars.
He was elected to the positions of Vice-President (1897) and President (1898) of the French Academy of Sciences.

David Beaglehole (8 January 1938 – 21 March 2014) was a New Zealand physicist.

Alexei Vladimir "Alex" Filippenko (; born July 25, 1958) is an American astrophysicist and professor of astronomy at the University of California, Berkeley. Filippenko graduated from Dos Pueblos High School in Goleta, California. He received a Bachelor of Arts in physics from the University of California, Santa Barbara in 1979 and a Ph.D. in astronomy from the California Institute of Technology in 1984, where he was a Hertz Foundation Fellow. He was a postdoctoral Miller Fellow at Berkeley from 1984 to 1986 and was appointed to Berkeley's faculty in 1986. In 1996 and 2005, he a Miller Research Professor, and he is currently a Senior Miller Fellow. His research focuses on supernovae and active galaxies at optical, ultraviolet, and near-infrared wavelengths, as well as on black holes, gamma-ray bursts, and the expansion of the Universe.

George Edward Alcorn Jr. (born March 22, 1940) is an American physicist, engineer, inventor, and professor. He taught at Howard University and the University of the District of Columbia, and worked primarily for IBM and NASA. He has over 30 inventions and 8 patents resulting in his induction into the National Inventors Hall of Fame in 2015.