Nobody has actually been able to smell the surface of the Moon, because visiting astronauts had keep their faces inside their spacesuit helmets to be able to breathe. The Moon's surface is covered with a fine powder, also called lunar soil or moondust, that clings to astronauts' spacesuits, boots and gloves. When they were back in their ships, astronauts observed that the moondust smelled like gunpowder. Many astronauts have experience in handling firearms, so it makes sense that they would be able to identify the gunpowder-like scent of lunar soil.
More about moondust:
- Astronauts described lunar soil as both soft and abrasive.
- There is significant concern in the scientific community that moondust could have damaging effects on the health of astronauts as well as the machinery of spaceships.
- Despite the similarity in fragrance, gunpowder and moondust do not have the same chemical composition. Scientists do not understand why the substances smell so much alike, although some have suggested that moondust takes on the gunpowder smell only after it has been brought into the relatively moist atmosphere of a spaceship.