astrophysicist responsible for theories regarding the formation of the
unstable element technetium within the core of red giant stars and of
the disappearance of Earth's original atmosphere.
Cameron was born in Winnipeg, Manitoba, and educated at Manitoba and
Saskatchewan. He emigrated to the USA 1959 and held successive posts
at the California Institute of Technology; the Goddard Institute for
Space Studies, New York; and Yeshiva University, New York. In 1973 he
became professor of astronomy at Harvard.
Spectral lines denote the presence in red giants of technetium, an element
too unstable to have existed for as long as the giants themselves. This
means the element is created in the stellar core. Cameron suggested
that technetium-97 (half-life 2.6 x 106 years) might result from the
decay of a nucleus of molybdenum-97, a usually stable nuclide that becomes
unstable when it absorbs an X-ray photon at high temperatures.
Cameron also suggested that the Earth's original atmosphere was blown
off into space by the early solar 'gale' - as opposed to the present
weak solar 'breeze' - with its associated magnetic fields.