It also occurs in the Earth's crust in minute traces from the spontaneous fission of uranium, but its short half-life -- one and a half million years for the 98 isotope -- means it could not have been an original consitutuent element on Earth.
In 1952, American astronomer Paul Merrill discovered that the 99 isotope of this element is present in S-type stars.  It also occurs in the Earth's crust in minute traces from the spontaneous fission of uranium, but its short half-life -- one and a half million years for the 98 isotope -- means it could not have been an original consitutuent element on Earth. FTP, name this element first discovered in a sample of molybdenum that had been bombarded with deuterons at Berkeley by Carlo Perrier and Emilio Segre (SEG-ray).
In 1952, American astronomer Paul Merrill discovered that the 99 isotope of this element is present in S-type stars.  
Technetium