People naturally assume that space is devoid of any smells. Its very nature (and emptiness) makes it impossible for us to imagine the cosmos having any sort of defining features. After all, how could Nothingness smell like anything?
However, we have proof otherwise. Apparently, smell does persist in the vacuum of the universe, despite what common sense might suggest. It’s fairly obvious that you cannot survive in a vacuum, so you can’t really smell space first-hand, but a distinct smell has always been noted every time an astronaut has come back to the space station after his/her space walk. The smell of space clings to the space suit, making it possible for humans to safely assess its characteristics – and odor!
Here’s what astronauts over the years have had to say about their impressions of the stench of space.
What Astronauts Say
Don Pettit, an astonishingly poetic astronaut, has this to say regarding the topic on the NASA blog:
“The best description I can come up with is metallic; a rather pleasant sweet metallic sensation. It reminded me of my college summers where I labored for many hours with an arc welding torch repairing heavy equipment for a small logging outfit. It reminded me of pleasant sweet-smelling welding fumes. That is the smell of space.”
Other astronauts have had eerily similar olfactory experiences regarding space. Most of them compare it to the scents of burning metal, steak and welding. Take three-time spacewalker Thomas Jones, for example. He states that space smells sulfurous, somewhat like gunpowder, while also carrying ‘a distinct odor of ozone, an acrid smell’. To Alexander Gerst, space smells like a combination of fragrances – namely walnuts and the brake pads of a motorbike. Space tourist Anousheh Ansari wrote in her blog that it was ‘strange…kind of like a burnt almond cookie’. Even Buzz Aldrin, the legendary astronaut of Apollo 11, compared the odor to burnt charcoal.
Causes
There seems to be a consensus as to what space smells like, but what generates the smell in the first place?
The boring answer is that it’s probably due to the air ducts that recompress the compartment once the astronaut comes back inside. Materials, like the spacesuit for example, which had been exposed to a vacuum, can react strongly if suddenly brought back into an atmosphere that is rich in oxygen. The reaction that occurs is similar to combustion within the Earth’s atmosphere, which also depends on oxidation for burning. That being said, the vacuum-to-atmosphere reaction burns at a much faster rate, thus causing the burning aroma.
So, does that mean that the smell is just a reaction within the spacecraft and not actually an interstellar aroma? Does that mean we’ve been duped?! Come on Science, we deserve a better answer than that!
