Apollo 17 astronaut Harrison Schmitt was allergic to moon dust

What are the chances of discovering you have an allergy to something that doesn't exist on Earth? For astronaut Harrison Jack Schmitt, the chances are 100%. In 1972, Harrison took part in the final NASA Apollo mission to the moon before the program was discarded and was in fact the last living man to walk on the moon. While strolling across the moon for the last time, he accidentally inhaled some lunar dust that made him sick and credited him with the only known allergy to a substance not on this planet.