In 1972, Harrison Schmitt became the most recent person to walk on the moon, joining 11 others who can claim that miraculous feat. But the moon must not have liked being trampled on: No sooner did Schmitt take his helmet off inside the lunar capsule than his nasal passages swelled and he became congested. The cause was the moon dust that Schmitt and his crew mates were bringing back to Earth, both by accident and on purpose. Soil samples that they collected included one that NASA has called “the most interesting sample” ever brought back. Luckily for Schmitt, the congestion passed quickly. “First time I smelled the dust I had an allergic reaction, the inside of my nose became swollen, you could hear it in my voice. But that gradually went away for me, and by the fourth time I inhaled lunar dust I didn’t notice that.” Still, Schmitt says the reaction made it clear that we need to gain a better understanding of how mankind reacts to places like the moon, if for no other reason than to ensure a safe return. Currently, NASA plans to again send humans to the moon — including a woman for the first time — by the year 2024.
More about moon dust:
Silicon dioxide is the main component of moon dust, which also contains iron, magnesium, and calcium.
Astronauts have tasted moon dust, and they say it smells and tastes like gunpowder.
Moon dust lies on the lunar surface but also floats above it for nearly 60 miles (96.5 km).