William Cassidy
The geologist who founded ANSMET, the American programme that has brought more than 20,000 meteorites in from the Antarctic ice.
Key facts
- Born
- 1928
- Died
- 2020
- Nationality
- American
- Field
- Geologist
William Alfred Cassidy, known as Bill, began his career studying impact craters. From the early 1960s he led expeditions to Campo del Cielo in northern Argentina, a field of more than two dozen small craters made about 4,000 years ago by a shower of iron meteorites. He excavated craters and recovered irons there for decades, working into his eighties.
In 1973, at the University of Pittsburgh, Cassidy heard how Japanese teams were finding meteorites on the blue ice near the Yamato Mountains. He realised that the Antarctic ice sheet might hold huge numbers of them and began asking for funding to search. After several refusals, he was funded for the 1976 to 1977 season and went south with the curator Edward Olsen and the Japanese geologist Keizo Yanai.
That first season, and those that followed at the Allan Hills, were a great success. The programme became known as ANSMET, the Antarctic Search for Meteorites, run with NASA and the Smithsonian Institution. Its teams have recovered meteorites from the Moon and Mars, including ALH 84001, and every specimen is made available to researchers worldwide.
Cassidy led ANSMET for many years and described the work in a book in 2003. Cassidy Glacier in Antarctica, the mineral cassidyite and the asteroid 3382 Cassidy are named after him.
On the timeline
- December 1976The first American Antarctic search
See more
The Campo del Cielo meteoriteThe ALH 84001 meteoriteThe Allan Hills 81005 meteorite