Frederick Charles Leonard (March 12, 1896 – June 23, 1960) [1] was an American astronomer. As a faculty member at the University of California, Los Angeles, he conducted extensive research on double stars and meteorites, largely shaping the university's Department of Astronomy. He received his undergraduate degree from the University of Chicago in 1918 and his PhD in astronomy from the University of California, Berkeley in 1921. Leonard was an astronomer from his teenage years, founding the Society for Practical Astronomy in 1909. [2] In 1933 he founded The Society for Research on Meteorites, which later became known as the Meteoritical Society. He was its first president and was the Editor of the Society's journal for the next 25 years. [3] The Society instituted the Leonard Medal in 1962, its premier award for outstanding contributions to the science of meteoritics and closely allied fields. [4]
Leonard was born in Mount Vernon, Indiana in 1896 and moved with his family to Chicago in about 1900, eventually settling near the University of Chicago. [5] From the age of eight, he showed great interest in the stars and by early adolescence had become an active amateur astronomer. In 1909 he attended the annual meeting of the Astronomical and Astrophysical Society of America, held at the Yerkes Observatory. The same year, he organized the Society for Practical Astronomy (SPA), [6] a national amateur organization. Leonard's leadership raised concerns among professional astronomers [2] as not all were in favor of amateur contributions to the profession. [7] [8] Nonetheless, the organization flourished until Leonard's departure in 1919. [9]
Leonard was a prolific writer and by the age of 14 [10] had attracted the attention of numerous publishers. [11] He authored a year-long series of articles titled "Mr. Leonard's Star Colors" in the English Mechanic and World of Science. [11] A Chicago Tribune reporter characterized him as a "co-worker with such savants as Prof. F. R. Moulton" [11] and Francis P. Leavenworth.
After graduating from Hyde Park High School in Chicago, Leonard completed his bachelor's and master's degrees at the University of Chicago. He continued his graduate education at the University of California, Berkeley with Armin Leuschner, being awarded his PhD in 1922 [12] for his thesis "An Investigation of the Spectra of Visual Double Stars". [13]
Leonard joined the University of California, Los Angeles faculty in 1922 as instructor of astronomy in the Department of Mathematics [14] [15] and founded the Department of Astronomy in 1931 [15] which he headed till his death in 1960.
Leonard initially focused his university research on double stars, which he studied using the facilities at Mount Wilson Observatory. [9] (The equipment for astronomy teaching was very poor at that time; but he got access to telescopes on Mt.Wilson and continued to observe stars and planets for some years). [14] The University didn't obtain the research university mandate till after the World War II. Before shifting his focus to meteoritics he discovered at least 25 double stars. [5] His interest in meteorites started in the mid to late 1920s. [16] Leonard started corresponding with Harvey H. Nininger about meteorite purchases in 1930, [17] and from that point forward, the majority of Leonard's contributions to astronomy surrounded his study of meteorites with a special focus on their systematics and statistics. [9] In 1933 he founded The Society for Research on Meteorites, now known as the Meteoritical Society, with himself as president and Harvey H. Nininger as secretary. [18] [19] He accumulated a large collection of meteorites, examining them as part of his studies to form a revised and simplified meteorite classification scheme. Although the scheme's validity is still a subject of some controversy, it remains one of Leonard's most well-known contributions. [9] Leonard translated his research into teaching material and offered the first class in Meteoritics at the university in 1937. [20] He did his best for the Meteoritical Society to flourish and managed a lot of difficulties during WWII and especially after the war period. [14]
Throughout Leonard's career, even during times of intense research, teaching remained his primary dedication. [9] Three of "Leonard’s prize pupils" became planetarium directors later in life. [21] He was honoured by "striking a medal in his name" after his death for the contribution he had made to the development of the Meteoritical Society [14]
Leonard was one of the first astronomers to hypothesize the existence of a trans-Neptunian population. [22] In 1930, soon after Pluto's discovery by Clyde Tombaugh, Leonard pondered whether it was "not likely that in Pluto there has come to light the first of a series of ultra-Neptunian bodies, the remaining members of which still await discovery but which are destined eventually to be detected". [22]
Leonard married Rhoda Walton in Victoria, B. C., Canada in 1942. [23] They had two sons – Roderick and Frederick.
Leonard suffered a stroke in May 1960 and died on June 23. [5]
A meteorite is a rock that originated in outer space and has fallen to the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples "bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater.
Pallas is the third-largest asteroid in the Solar System by volume and mass. It is the second asteroid to have been discovered, after Ceres, and is a likely remnant protoplanet. Like Ceres, it is believed to have a mineral composition similar to carbonaceous chondrite meteorites, though significantly less hydrated than Ceres. It is 79% the mass of Vesta and 22% the mass of Ceres, constituting an estimated 7% of the mass of the asteroid belt. Its estimated volume is equivalent to a sphere 507 to 515 kilometers in diameter, 90–95% the volume of Vesta.
Meteor Crater, or Barringer Crater, is an impact crater about 37 mi (60 km) east of Flagstaff and 18 mi (29 km) west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are officially called the Canyon Diablo Meteorite, after the adjacent Canyon Diablo.
George Ogden Abell was an American educator. Teaching at UCLA, priorly he worked as a research astronomer, administrator, as a popularizer of science and of education, and as a skeptic. He earned his B.S. in 1951, his M.S. in 1952 and his Ph.D. in 1957, all from the California Institute of Technology. He was a Ph.D. student under Donald Osterbrock. His astronomy career began as a tour guide at the Griffith Observatory in Los Angeles. Abell made great contributions to astronomical knowledge which resulted from his work during and after the National Geographic Society - Palomar Observatory Sky Survey, especially concerning clusters of galaxies and planetary nebulae. A galaxy, an asteroid, a periodic comet, and an observatory are all named in his honor. His teaching career extended beyond the campus of UCLA to the high school student oriented Summer Science Program, and educational television. He not only taught about science but also about what is not science. He was an originating member of the Committee on Scientific Investigation of Claims of the Paranormal now known as the Committee for Skeptical Inquiry.
Carlyle Smith Beals, FRS was a Canadian astronomer.
Brother Guy J. Consolmagno, SJ, is an American research astronomer, physicist, religious brother, director of the Vatican Observatory, and President of the Vatican Observatory Foundation.
A micrometeorite is a micrometeoroid that has survived entry through the Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. The IAU officially defines meteoroids as 30 micrometers to 1 meter; micrometeorites are the small end of the range (~submillimeter). They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).
Meteoritics is the science that deals with meteors, meteorites, and meteoroids. It is closely connected to cosmochemistry, mineralogy and geochemistry. A specialist who studies meteoritics is known as a meteoriticist.
Harvey Harlow Nininger was an American meteoriticist and educator. Although he was self-taught, he revived interest in scientific study of meteorites in the 1930s and assembled the largest personal collection of meteorites up to that time.
Alastair G. W. Cameron was an American–Canadian astrophysicist and space scientist who was an eminent staff member of the Astronomy department of Harvard University. He was one of the founders of the field of nuclear astrophysics, advanced the theory that the Moon was created by the giant impact of a Mars-sized object with the early Earth, and was an early adopter of computer technology in astrophysics.
Oscar E. Monnig was an American amateur astronomer, acknowledged for his contributions to meteoritics.
Meteoritics & Planetary Science is a monthly peer-reviewed scientific journal published by Wiley-Blackwell on behalf of the Meteoritical Society. It specialises in the fields of meteoritics and planetary science.
A meteor air burst is a type of air burst in which a meteoroid explodes after entering a planetary body's atmosphere. This fate leads them to be called fireballs or bolides, with the brightest air bursts known as superbolides. Such meteoroids were originally asteroids and comets of a few to several tens of meters in diameter. This separates them from the much smaller and far more common "shooting stars", that usually burn up quickly upon atmospheric entry.
European Fireball Network is an international astronomy organization based in Central Europe. Its purpose is systematic and simultaneous night observation of meteors and other nebular objects.
The Grant Meteorite is a meteorite that was discovered in the Zuni Mountains, about 45 miles (72 km) south of Grants, New Mexico. It was unearthed in 1929 although the date of its original groundfall is unknown.
The Vermillion meteorite is a pallasite (stony-iron) meteorite and one of two members of the pyroxene pallasite grouplet.
Robert Norman Clayton was a Canadian-American chemist and academic. He was the Enrico Fermi Distinguished Service Professor Emeritus of Chemistry at the University of Chicago. Clayton studied cosmochemistry and held a joint appointment in the university's geophysical sciences department. He was a member of the National Academy of Sciences and was named a fellow of several academic societies, including the Royal Society.
Toshiko K. Mayeda was a Japanese American chemist who worked at the Enrico Fermi Institute in the University of Chicago. She worked on climate science and meteorites from 1958 to 2004.
Katharina Lodders is a German-American planetary scientist and cosmochemist who works as a research professor in the Department of Earth and Planetary Sciences at Washington University in St. Louis, where she co-directs the Planetary Chemistry Laboratory. Her research concerns the chemical composition of solar and stellar environments, including the atmospheres of planets, exoplanets, and brown dwarfs, and the study of the temperatures at which elements condense in stellar environments.
{{cite book}}
: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)Hockey, Thomas A; Bracher, Katherine (November 20, 2007), The Biographical Encyclopedia of Astronomers, Springer (published 2007), ISBN 978-0-387-31022-0
Leonard, Frederick D. (March 1, 2018). "Frederick C. Leonard: A history and personal recollections". Meteoritics & Planetary Science. 53 (3): 359–374. Bibcode:2018M&PS...53..359L. doi: 10.1111/maps.13015 . ISSN 1945-5100. S2CID 134276257.