The Sweet Smell of Molecules
Jan. 23, 2012
A vacuum is a condition that is nearly devoid of molecules, and space is a molecular desert that makes the Empty Quarter of the Saudi Arabian peninsula seem like an oasis in comparison. But the space vacuum still has some molecules—residue from galactic processes, solar wind or atomic detritus spalled off from our atmosphere. And molecules, typically floating in the surrounding air, can be sensed via smell.
To talk about the smell of space makes no sense at all. Even if we had space-adapted noses, there is no air to transport the trace molecules. However, space does have a definite smell, and we can smell it in a roundabout way.
I have had the pleasure of operating our space station airlock for many crewmates while they went on spacewalks. Each time, when I repressurized the airlock, opened the hatch, and greeted my tired returning friends, a peculiar essence drifting about the newly repressurized chamber tickled my olfactory senses. I noticed that the smell was coming from the spacesuit fabric, the tools, and any other equipment that had been brought inside. It was more pronounced on fabrics than on metal or plastic surfaces. It most definitely did not come from the air lines that pressurized the chamber.
That’s me with John Herrington in the Quest Airlock during the STS-113 Endeavour mission to the International Space Station in 2002.
At first I couldn’t quite place the smell. The best description I can come up with is that it’s rather pleasantly metallic. It brought me back to my college summers, when I used an arc welding torch to repair heavy equipment for a small logging outfit. It reminded me of sweet-smelling welding fumes. To me this is the smell of space.
Reptiles have smell sensors located not within their nasal passage, but on the roof of their mouth. They smell by waving their moist tongue in the air, then pressing it against the roof of their mouth, thus indirectly transferring molecules from the air to the olfactory sensors. It occurred to me that I was smelling the essence of space through an indirect transfer, in a manner not unlike that of our lizard friends.
Other posts by this author
- A Poem for Saturday: Embrace Me, May 5, 2003
- A Poem for Saturday: Helen of Earth
- From the Diary of a Space Zucchini: Fresh Air
- From the Diary of a Space Zucchini: My Aching Roots
- Personal Reality
- A Poem for Saturday: I Wonder Why
- From the Diary of a Space Zucchini: Crewmates for Astro-Z
- Astro-Z in Zero-G: The Diary of A Space Zucchini - A Rose
- Astro-Z in Zero-G: The Diary of a Space Zucchini - Part 1
- Europe's Automated Transfer Vehicle Docks
Jan. 24, 2012
beth b.
Mike Fincke thinks space smells like burnt cookies. That's my kind of sweet smell of space. Makes me want to burn a pan now, in your honor. :)
Jan. 29, 2012
Paul T.
Don, the only thing I can think to compare this to would be ionized air. What you describe is what I would compare to the smell of my living room after playing with slot cars when I was a kid. My brother and I would run those things until they were hot to the touch, and the room would have a distinct ionized smell. Now and then I encounter that smell when electric motors are running. I always associate that smell with fun!
Is the smell of space similar?
Jan. 30, 2012
Jacob F.
The molecules coalescing on your EVA suits is "planet-building" going on a micro scale, I presume. How interesting!