Where Does The Moon's Smell Come From?

No, it's not from the cheese.

What's That Smell?

NASA

In 1969, mankind got its first few whiffs of the lunar surface after astronauts tracked moon dust into the Apollo lander.

In an article on Space.com, Apollo 17 astronaut Harrison "Jack" Schmitt describes the Moon's scent as being similar to spent gunpowder. Buzz Aldrin of Apollo 11 says it smells like charcoal, or fireplace ashes sprinkled with water. And scientist Larry Taylor, director of the Planetary Geosciences Institute at the University of Tennessee in Knoxville, thinks he knows where the lunar regolith -- the layer of dust, sand, and rock on the Moon's surface -- derives its scorched aroma: the broken electron bonds between atoms. Columnist Leonard David explains:

Taylor said that when a geologist smashes a rock here on Earth, that person will smell some odor that has been generated by the smashing of minerals, thereby creating the so-called dangling bonds. But on the moon, the dangling bonds can exist for a long time, Taylor said. And because lunar rock and soil is roughly 43-percent oxygen, most of these unsatisfied bonds are from oxygen. "In a nut-shell, I believe that the astronauts all smelled unsatisfied dangling bonds on the lunar dust … which were readily satisfied in a second by the lunar module atmosphere, or nose membrane moisture," Taylor told Space.com.

Apparently the rest of space smells like a Nascar race for similar reasons.

For a more detailed account of astronauts' first encounters with moon dust (including the fact that they were worried it might explode inside the cabin), check out the Space.com article.