Every form of the element technetium is radioactive. Not surprisingly, it’s found nowhere on Earth, except in particle accelerators, where we make it on demand. Technetium exhibits this distinction in its name, which derives from the Greek technetos meaning “artificial.” For reasons not yet fully understood, technetium lives in the atmospheres of a select subset of red giant stars. This alone would not be cause for alarm except that technetium has a half-life of a mere two-million years, which is much, much shorter than the age and life expectancy of the stars in which it is found. In other words, the star cannot have been born with the stuff, for if it were, there would be none left by now. There is also no known mechanism to create technetium in a star’s core and have it dredge itself up to the surface where it is observed, which has led to exotic theories that have yet to achieve consensus in the astrophysics community. Not to worry. Inventive theorists eventually found a way to not only make technetium in the depths of stars, but also dredge it rapidly to the surface where it is observed. So all is well in the universe.
~Neil deGrasse Tyson