Norman Horowitz (geneticist)
Norman Harold Horowitz (March 19, 1915 – June 1, 2005) was a geneticist at Caltech who achieved national fame as the scientist who devised experiments to determine whether life might exist on Mars. His experiments were carried out by the Viking Lander of 1976, the first U.S. mission to successfully land an unmanned probe on the surface of Mars.
Horowitz was a member of both the National Academy of Sciences and the American Academy of Arts and Sciences. In 1965 he began work with the Jet Propulsion Laboratory in Pasadena, serving for five years as chief of JPL’s bioscience section and as a member of the science teams for the Mariner and Viking missions to Mars. From 1977 to 1980, he was chairman of the biology division at Caltech.
Among advocates of space exploration, he was noted for his opposition to a space program centered on the use of human astronauts. Charlene Anderson recalls, "In personal discussions, he could be particularly vociferous on the topic of human versus robotic exploration. Norm argued that human exploration could only interfere with scientific exploration and confuse the public as to why we should explore space. In his view, science should drive the endeavor, not a lust for adventure."
Scientific career 
Horowitz earned his BS in biology at the University of Pittsburgh in 1936 where his experience conducting research as an undergraduate help to persuade him to pursue further graduate training in science. He later established the endowed Norman H. Horowitz Fellowship at the University of Pittsburgh to support undergraduate research. He completed his PhD at Caltech in 1939 under embryologist Albert Tyler, and then became a postdoctoral researcher at Stanford University in the laboratory of George W. Beadle. Horowitz returned to Caltech as a faculty member in 1946 and stayed at the Institute for the remainder of his career. He served as chair of the Biology Division from 1977 to 1980, and became professor emeritus in 1982.
As a scientist, Horowitz is best known for his discovery and demonstration in 1944 that a metabolic pathway is a series of steps, each catalyzed by a single enzyme. Working with Neurospora crassa, Horowitz demonstrated that each step in the metabolism of arginine from its precursors depends on the intactness of a single gene. His discovery helped to clinch the case for George Beadle and Edward Tatum's "one gene-one enzyme hypothesis" (a term Horowitz coined for their concept).
- Horowtiz, N. (1987). "Man on Mars: A Turnabout". Science 238 (4823): 10–11. doi:10.1126/science.3659898. PMID 3659898.
- Metzenberg, R. L. (2005). "Norman Harold Horowitz, 1915–2005". Genetics 171 (4): 1445–1448. PMC 1456073. PMID 16371517.
- The Norman H. Horowitz Fellowship, accessdate=2009-02-06
- Horowitz, N. H. (1995). "George Wells Beadle. 23 October 1903-9 June 1989". Biographical Memoirs of Fellows of the Royal Society 41: 44–26. doi:10.1098/rsbm.1995.0003.
- Norman Horowitz Dies; Conducted Experiment with Viking Lander to Search for Life on Mars. Caltech Press Release, June 1, 2005.
- The Times, 27 August 1976, Experiment points to life in Mars soil
Further reading 
- Anderson, Charlene. In Memoriam: Norman Horowitz (1915-2005) The Planetary Society.
- Horowitz, N. H. (1945). "On the Evolution of Biochemical Syntheses". Proceedings of the National Academy of Sciences of the United States of America 31 (6): 153–157. PMC 1078786. PMID 16578152.
- Horowitz, Norman Harold (1986). To utopia and back: the search for life in the solar system. San Francisco: W.H. Freeman. ISBN 0-7167-1766-2.