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What Does Space Smell Like?

Image credit: NASA


What is the smell clinging to an astronaut after a spacewalk? Some have described it as an acrid aroma — others say it reminds them of seared steak.  After a 2003 mission, astronaut Don Pettit attempted to be a little more precise:

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.

NASA hired chemist Steven Pearce to recreate the odor here on earth.  With his help astronauts-in-training get a little taste — or sniff — of what’s to come after liftoff.

For all the latest science news, check out the National Geographic’s twice-weekly news rundown, EarthCurrent.


  1. Rebecca
    Perth, Australia
    August 10, 2012, 11:51 am

    Quantum physics tells us that space is not a vacuum. I don’t doubt there could be an ‘odour’. The question I ask is whether our olfactory sensory system can pick up this odour, or of is it something man-made that they are smelling. The sensory patches in the nose are detecting something, but what?

  2. Pilot
    August 10, 2012, 4:07 am

    After inhaling pure O2 for a period of time, one’s lungs and nostrils are mildly irritated, therefore sense of smell is enhanced. This metallic-charred smell is nothing more than the ambient smell of the spacecraft’s interior. After the brief description above, I believe it closely matches the same smell we experience in any civil flight simulator…

  3. Karl Hickel
    August 9, 2012, 9:58 pm

    If it smells like something. Would not that something be in molecular relationship to whatever it smells like on earth allbiet poisonous and non eatable?

  4. Bob D
    August 9, 2012, 1:02 pm

    Of course they’re talking about the smell from all of the equipment combined with body odor in a constrained space – the smell of going to space, not the smell of space itself. A big contributor is probably ozone, plus emissions from plastics.

  5. Calla
    August 9, 2012, 12:40 pm

    Make sure Demeter fragrance company gets that scent so we can all buy it! I can see it now, “space” a special edition scent in collaboration with NASA

  6. Lorena
    Earth close to Pacific Ocean
    August 9, 2012, 10:48 am

    Let me understand this, how can they smell the space or out there, if you can not breath????? There is no oxygen…!!!! To smell something is when you give a breath!!!!!!!!!!!!!

  7. Zoë
    August 9, 2012, 10:26 am

    Space is a vacuum more or less, but not completely… because every body put there (planets, stars, etc…) are giving off particles, elements, even molecules that are moving around… Never mind the ever present fields (tiny, but still there) and traveling neutrinos and other subatomic particles… there is the quantum effect of moving particles… I imagine the scent is the scent of stars in the making and un-making. Welding seems appropriate. I like.

  8. vince
    August 9, 2012, 10:21 am

    the comparison to arc welding makes me think that it’s maybe radiation induced damage to the suit’s surface

  9. Daniel Miller
    August 9, 2012, 10:13 am

    Would that not be the smell of pollutants rising from Earth ?

  10. krishna kumar G
    August 9, 2012, 9:59 am

    Smell may differ at different places Near to Earth It may smell Like Tyre Burning smell,Near Sun it may Smell like Volcano .

  11. Joao
    August 9, 2012, 9:44 am

    There are different kinds of radiation in space which are probably creating this “space scent”, regardless of the vacuum.

  12. nokuthula siziba
    August 9, 2012, 9:44 am

    i luv national geography

  13. joe
    st louis, mo
    August 9, 2012, 9:42 am

    There is no such thing as a perfect vacume in nature. Space is full of tiny particles or space dust which I assume stick to a space suit and upon entering a earth like environment begin to decay rapidly giving off a scent.

  14. Pak Nagasing
    United States
    August 9, 2012, 8:29 am

    Interesting tidbits. like it. Don’t know why but I was also thinking of grilled cheese among other substance out there.

  15. Nadrah
    August 9, 2012, 8:23 am

    I never think that space have a smell

  16. Richie John
    Democratic Republic of India
    August 9, 2012, 8:18 am

    objection to the statement that there’s odor in space,which is basically vacuum. n of cz there’s dust. +asteroids releasing gases into space.but still that would be infinitesimal when compared to the size of this expanding universe.so kinda sceptical abt d claim.abt space havin an odor.

  17. JDM
    St. louis, MO
    August 9, 2012, 8:13 am

    You can’t smell sweet. Things also don’t smell sour, bitter, salty, or umami. These five cardinal tastes are things that we perceive with our tastebuds.

  18. Richie John
    August 9, 2012, 8:13 am

    objection to the statement that there’s odor in space,which is basically vacuum. n of cz there’s dust. +asteroids releasing gases into space.but still that would be infinitesimal when compared to the size of this expanding universe.so kinda sceptical abt d claim.

  19. greg
    August 9, 2012, 7:39 am

    Ok…so tell me do you smell fudge..lol

  20. fatih tas
    August 9, 2012, 7:39 am

    How can you smell it, there is no air!

  21. muhammad shahzad
    karachi pakistan
    August 9, 2012, 7:35 am


  22. Riaad Barnes
    Cape town,South Africa
    August 9, 2012, 7:14 am

    I’ve always thought,that space did have a smell to it,but i imagine it would smell like,fresh and cool air.not somethng metalic.lol

  23. John Trainer
    New Hampshire
    August 9, 2012, 6:59 am

    Makes sense that if you could really smell space, it would smell like an arc welding torch. Just like that big yellow blow torch in the sky. I’m pretty sure that what they are smelling is not space, but residual particles from the reaction control systems (thrusters).

  24. Sfynx
    August 9, 2012, 6:45 am

    I’d say it is exactly this lack of smell that causes these sensations, just like you will start seeing green spots after staring into red spots for too long… the brain overcompensates a changed situation.
    Well, that’s my hypothesis 😛

  25. Peter C Masters
    Southern England
    August 9, 2012, 5:58 am

    I’m not sure it is that absurd for NASA to entertain the idea that space would ‘smell’. Firstly, space is not totally empty, rather it contains rarefied amounts of particles of hydrogen and helium, but saying that- these elements are odourless. What is interesting though is that most extra-vehicular activity on space missions occur very close to earth, in low-earth orbit where there is still a significant influence from the earth’s atmosphere, enough even for air particles to cause a drag effect on orbiting craft. I wonder if astronauts who spacewalk are actually smelling the earth on their suits, albeit, in miniscule amounts?

  26. Usama Nagy
    Dubai, UAE
    August 9, 2012, 5:53 am

    That’s funny! Astronauts are breathing oxygen in their space suits and none of them smell anything except the inside of their suits 🙂

  27. Kirk
    August 9, 2012, 5:51 am

    That of the living tissue sensory can create many familiar sensations on it’s own, especially from various frequencies. Space is not exactly “nothingness”… for there ultra-violet rays, very strong radioactive waves, cosmic rays and perhaps much more from what I was taught in public school. Even a black-hole is from a gravitational pull of super density. All of the Universe and most likely way beyond seems to be teeming with subatomic energy that had to exist before “The Ultimate Space Kablooey”

  28. Kris Wingfield
    Wichita, KS
    August 9, 2012, 5:49 am

    Too many people herein seem to think smell must be airborne to be perceived and thus can not exist in space. You should know you are wrong there since aquatic life smells too.

    The vacuum of space does not keep chemicals from being released, it merely keeps us from inhaling to smell them. Just as the vacuum keeps sound waves from traveling, I’m sure everything in space also has a sound (one just needs to produce the proper medium to hear it).

    I’m sure that arc welder metallic scent described above comes from the fact that a fair amount of things in space are very hot with very high metal concentrations. With all of the tiny (and enormous) things floating in space and our very hot sun shooting waves of energy our away from it, I’m sure their space suits get bombarded with all kinds of microscopic burnt minerals and elements.

    In short, it smells like an arc welder because they are eight lightminutes away from the largest arc welder in the solar system.

  29. pimeto
    August 9, 2012, 5:43 am

    Well, how did they smell the “space” ?
    Did some astronaut got out in space and took of his helmet ? Or is it a theory ? ANyways, its funny article!

  30. Susan Avila
    August 9, 2012, 5:41 am

    …The universe smells like rasberries!!

  31. ivan richard
    August 9, 2012, 5:34 am

    How come an airless space have an odor? I think we can smell things with air as the media.. We cannot even breath in space.. How come we can smell the odor? So I think its the odor of the space shuttle and the space suit..

  32. pidpub
    August 9, 2012, 5:27 am

    i have guessed that somebody has opened their helmet and sniff the fume of space without being sucked-out of their helmet.. LOL!

  33. kelly
    August 9, 2012, 5:22 am

    i think they’re describing their space suits’ burnt smell from the bare exposure to the sun? haha! my humble, long shot opinion..

  34. Bill
    August 9, 2012, 5:10 am

    For a moment..I thought it was something exciting to talk about like…it smell like McDonald kitchen ;0)

  35. mujtaba
    August 9, 2012, 4:55 am

    It would be a feeling of smell. Otherwise how do u smell vaccume.

  36. Jobe Doug
    August 9, 2012, 4:43 am

    You are correct. Space is a vacuum, but to what you are referring, a place with no matter is a perfect vacuum. Space is not a perfect vacuum.
    Therefor it is underpressured but with particles of matter floating around, hence space can have such qualities as smell and a temperature

  37. Paul Okudo
    Nairobi, Kenya.
    August 9, 2012, 4:37 am

    My interest is not really swell but sound. Does engine noise and vibration reduce to silent as you leave earth? I hope folks on ISS get olympics coverage and music to relax.

  38. Adrian
    August 9, 2012, 4:37 am

    Astronauts who take space walks are not, as some here have posted, in a complete vacuum. While minute, there are traces of gases from the upper atmosphere, rocket exhaust, and minute particles of dust. They are so small, and so sparse that they don’t cause an immediate effect, but the drag from them is noticeable enough that the International Space Station does need to be boosted now and again due to atmospheric drag.

    So not only is it possible for something to coat the space suit of an astronaut on an EVA, it’s inevitable. Even if you left the Earth-Moon system, you would not be in a complete vacuum. Space is not absolutely empty, it’s just very very very empty by comparison.

  39. Tom L..
    August 9, 2012, 4:25 am

    The smell is likely the trillions of tiny meteors that orbit earth, like metal shavings. All it takes is a molecule to be smelled 🙂

  40. Ashley
    August 9, 2012, 4:22 am

    I am assuming that the reason why space smells like burnt food or melted metal is because of the forever explosions and expansion of the galaxies, stars, and such. It only makes sense to me this way.

  41. Bea
    August 9, 2012, 4:17 am

    I’d attribute the smell clinging to the suit more to the spacecraft itself or to the equipment handled whilst wearing the suit than to space, as everyone keeps pointing out: space being a vacuum shouldn’t have a smell.. :S

  42. Mike Johnson
    Southern California
    August 9, 2012, 4:10 am

    I’m pretty sure I’ve heard that even in the vacuum of space you’d still come in contact with small bits of particles like hydrogen and helium as well as radiation. They obviously can’t smell the outside of their suit while they’re wearing them and especially when outside the shuttle. But one inside I’d assume maybe all the hydrogen and stuff they come in contact with sticks to their suits and they can smell it since scent is particle based.

  43. Brax
    San Jose
    August 9, 2012, 4:07 am

    I thought that nose need some air to be able to smell… or not?

  44. Some random mate
    August 9, 2012, 4:02 am

    The outer space is not a perfect vacuum, because there is no such thing as a perfect vacuum . The interstellar space has a few hydrogen atoms per cubic meter . But he is the closest physical approximation of a perfect vacuum.

  45. Demy
    Manila, Philippines
    August 9, 2012, 4:01 am

    kala ko amoy air-con.. (i though it smells like air-con)

  46. daggan
    August 9, 2012, 3:59 am

    I thought space was full of particles and dust and cosmic rays, etc.

  47. John
    August 9, 2012, 3:55 am

    They are talking about the smell of the astronaut (suit) after he has been on a spacewalk but comes back inside the shuttle. It makes sense that it smells… metallic… machine-like… rock like… since I’m sure there are very small particles of space dust, stuff coming off the shuttle itself etc…. all being attracted to this object walking around out there.

  48. Nootan Ghimire
    August 9, 2012, 3:54 am

    If space smelled like that, wouldn,t vacuum smell the same? If that’s the case, why would you need chemist to render that smell?

  49. Jason
    August 9, 2012, 3:52 am

    It smells like victory.

  50. Ghassan
    Miami, USA
    August 9, 2012, 3:49 am

    I thought they can’t smell space because they are keeping the oxigen masks. Do they remove the masks and inhale?

  51. Ruslan Todorov
    August 9, 2012, 3:39 am

    How vacum can smell ??? 😀

  52. Eve
    August 9, 2012, 3:39 am

    I thought they couldn’t breath in space without their helmets, I am totally ignorant on the subject, but I thought space couldn’t be smelled

  53. Humdinger
    Budapest, Hungary
    August 9, 2012, 3:39 am

    Unless these astronauts did their “space walk” buck naked, I don’t see how their nostrils could have come in contact with anything remotely unaltered from space through their equipment. Not to mention the lack of particles to cause a smell to begin with. This sounds romantic, but space missions always seem to me like a large heap of money spent on things that concern us very little. There are plenty of problems to spend on here on earth.

  54. Rowan
    August 9, 2012, 3:38 am

    Space is not a perfect vacuum by any means, space contains heaps of stuff, planets, stars, galaxy’s as well as a heap of debris, dust and gasses etc… so small particles of dust and gasses may attach themselves to the suit in space and be carried back into the artificial atmosphere of the ship to release scent for those aboard. The only way that space is like a vacuum is that it has no pressure because it has no (conceivable or known) edges that contain the matter within it to create pressure.

  55. Sudhir
    August 9, 2012, 3:34 am

    Would it be something like ozone? like the smell you get when your extremely close to a lightning strike or an electric arc?

  56. Neda
    July 31, 2012, 1:59 am

    I was thinking that space doesn’t smell at all!

  57. doug jobe
    July 30, 2012, 2:30 pm

    It seems absurd that NASA would entertain the thought that space (a vacuum) would have a “smell” being that vacuums would have no elements to cause an odor. I would submit that the vacuum of space probably leached some chemicals or elements from the suits themselves, bringing them to the surface of the suit, where they could be smelled…

  58. Fazal Cheema
    United States
    July 30, 2012, 12:52 am

    as someone who is fascinated with fragrances and science, is there a way i can get to smell this fragrance which is made b Chemist Steven Pearce…i am willing to pay for it. it will be a great vaccine for my intellectual curiosity 🙂

  59. salim khan
    July 29, 2012, 11:28 pm

    i like national geography

  60. K-Alexander
    July 29, 2012, 9:58 pm

    Out of interest, would it not smell like nothing, as there is nothing to smell? Well, nothing but the presence of a human, and his equipment.
    As soon as we bleed, the blood exposed to the air instantly smells of iron (metallic).
    ” Firefighters say that cerebrospinal fluid burns up in a musky, sweet perfume”[http://www.slate.com/articles/news_and_politics/explainer/2007/03/barbyou.html] (sweet)
    (metallic + sweet)
    What is the path of elements to the human olfactory system and brain, without the effect of gravity?
    Would not the resulting sense be that of the human body itself rather than the smell space?

  61. Brian
    July 29, 2012, 9:57 pm

    It smells like the star around which the earth orbits.

  62. Patricia Hanson Locke
    Safety Harbor, Florida
    July 29, 2012, 9:25 pm

    “Burnt Chocolate Chip Cookies” said key note speaker Nasa’s top gun and astronaut who landed the space shuttle with no problems on more than one occasion.Speaking in front of an auditorium of 1st through 5th graders in Safety Harbor, FL
    I am so embarrassed to say this hero’s name has just slipped my mind….was it Andrews?!? Argh…..My apologies!

  63. Pandu
    Semarang, indonesia
    July 29, 2012, 9:11 pm

    Just can’t believe if those space have a smell like that…
    Where was that scent produced from…?