1972 — The “Sierra Leone,” the largest diamond uncovered to date at 969.8 carats, is found in Sierra Leone, Africa. Also that year:

_ Hexachlorophene, a widely-used germ killer, is banned when research shows that it may cause damage to the nervous system.

_ Pioneer 10 is launched to explore the asteroid belt and Jupiter. It is the first man-made object to leave the solar system.