Alfred O. C. Nier (1911 – 1994) is aptly called the “Father of modern mass spectrometry”. He developed the mass spectrometer from a rather cumbersome machine, difficult to build and maintain, to a much simpler instrument which revolutionized isotope geo- and cosmochemistry and other fields of science, some of which Nier pioneered himself.
He was trained in electronics engineering and physics at the University of Minnesota, where he also spent most of his career as a professor of Physics. His early fundamental contributions include the discovery of the rare isotope potassium-40, which later became the basis of potassium-argon dating, and studies of the isotopic composition of lead in ores, which formed the basis of uranium-thorium-lead geochronology and hence the now accepted age of the Earth. His studies of carbon isotopes in natural samples laid the foundation for stable isotope geochemistry. During World War II, Nier worked on the enrichment of uranium-235 as part of the Manhattan project. In the 1960s, he developed miniaturized mass spectrometers robust enough to be sent to Mars. During the Viking missions, such instruments provided the first data on the elemental and isotopic composition of the Martian atmosphere, data that were later crucial in determining that some of the meteorites in our collections are from the red planet. After his official retirement, Al Nier used a similar instrument to measure noble gases in tiny interplanetary dust particles.
Al Nier was a member of the U.S. National Academy of Sciences, received an honorary doctorate from his university, and has a martian crater and the mineral nierite discovered in meteorites named after him. In 1995, to honor the memory of Alfred O. C. Nier, an endowment gift given by Mrs. Ardis H. Nier established the Nier Prize, which is given annually and recognizes outstanding research in meteoritics and closely allied fields by early career scientists.