Toshiko Mayeda
The chemist who, with Robert Clayton, measured the oxygen isotopes of meteorites from every part of the Solar System.
Key facts
- Born
- 1923
- Died
- 2004
- Nationality
- American
- Field
- Chemist
Toshiko Kuki Mayeda was born in the United States to Japanese parents and spent part of her childhood in Japan. During the Second World War she was held in an internment camp for Japanese Americans. Afterwards she studied chemistry and in 1949 joined the laboratory of Harold Urey at the University of Chicago.
There she became an expert in measuring isotopes, first helping to show how oxygen isotopes in ancient shells record the temperature of past oceans. In the 1960s she began working with Robert Clayton, and their partnership lasted the rest of her life.
Mayeda carried out much of the painstaking laboratory work that separated oxygen from meteorite samples, using chemicals so reactive they had to be handled with great care. Together they measured oxygen isotopes in hundreds of meteorites and found that each group has its own distinctive mix. Their measurements helped show in 1983 that the Antarctic meteorite ALH A81005 came from the Moon, and that the SNC meteorites all come from Mars.
Mayeda was a co-author on more than a hundred research papers. The Meteoritical Society named an asteroid after her, and her work remains a foundation of how meteorites are classified.
On the timeline
- 1973Oxygen isotopes fingerprint meteorites
- 18 January 1982The first meteorite recognised from the Moon
See more
The Allan Hills 81005 meteoriteThe Allende meteorite