| ▲ | corysama 4 hours ago |
| I recall an article from a long time ago that basically said “astronauts report” the moon smells like spent gunpowder and outer space smell like… I think it was ozone. What they were actually reporting was the smell of the airlocks after they returned from their excursions. The moon has no atmosphere, so it has been accumulating dust from billions of years of asteroid impacts that have never come in contact with oxygen. Many of the chemicals in the dust are oxidative and so when it is exposed to air for the first time it rapidly oxidizes just like gunpowder! And I think the outer space report was from space walks, and the explanation was that the first time the airlock itself was exposed to hard vacuum, the surfaces of the airlock would have a reaction that left a scent of ozone. |
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| ▲ | jordanb 3 hours ago | parent | next [-] |
| There was some concern when Apollo 11 landed that when they repressurized the LEM with moon dust samples inside it would start a fire. I think they had a small test article that they blew a small stream of oxygen over to ensure it wouldn't auto-ignite. |
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| ▲ | helterskelter 4 hours ago | parent | prev | next [-] |
| At least some ISS astronauts describe smelling burnt metal after returning from EVA, if memory serves. (Others may smell ozone, I've just always remembered hearing burnt metal). |
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| ▲ | thescriptkiddie 3 hours ago | parent | next [-] | | the exterior of the ISS is constantly exposed to small mounts of atomic oxygen, which is an incredibly strong oxidizer. probably in addition to ozone there is a huge variety of organic and inorganic oxides that get tracked in through the airlock. https://en.wikipedia.org/wiki/Materials_International_Space_... | | |
| ▲ | sbierwagen 3 hours ago | parent [-] | | Fun trivia (well, perhaps not fun) in the second paragraph: "the Long Duration Exposure Facility (LDEF), which was retrieved in 1990 after spending 68 months in LEO" Long exposure, 68 months, right. But it was only supposed to be in orbit for 11! Challenger being destroyed on reentry made a mess of things. https://en.wikipedia.org/wiki/Long_Duration_Exposure_Facilit... >It was placed in low Earth orbit by Space Shuttle Challenger in April 1984. [...] At LDEF's launch, retrieval was scheduled for March 19, 1985, eleven months after deployment.[4] Schedules slipped, postponing the retrieval mission first to 1986, then indefinitely due to the Challenger disaster. After 5.7 years its orbit had decayed to about 175 nautical miles (324 km) and it was likely to burn up on reentry in a little over a month.[6][9]: 15 | | |
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| ▲ | junon 4 hours ago | parent | prev [-] | | I always heard burnt steak. |
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| ▲ | Bender 4 hours ago | parent | prev [-] |
| My UV sterilizing lights make my room smell like O3 Ozone and that smells nothing like spent gun-powder to me. The only other time I have smelled the same thing is when there has been mass lightening events in the sky. Were they talking about actual black powder or nitrocellulose? I've smelled black powder at the range when people bring out their antique rifles and that also does not smell like Ozone to me. |
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| ▲ | lifeisstillgood 4 minutes ago | parent | next [-] | | Sorry for the tangent, but you sterilise a whole room with UV light? Is that efficient ? Do you do it after tidying / cleaning ? Is there a medical reason for the extra part? Is it just cool :-) | |
| ▲ | mr_toad 3 hours ago | parent | prev | next [-] | | ‘Ozone’ is the smell of ionisation, ‘gunpowder’ the smell of oxidisation. | |
| ▲ | coffeebeqn 4 hours ago | parent | prev | next [-] | | Photocopiers smell like ozone when they run if anyone’s forgotten the smell | | |
| ▲ | saltcured 3 hours ago | parent | next [-] | | I also associate ozone with some electric motors, I think because they have brushes that arc during operation. Older power tools I encountered in the 1980s often did this, and you could see the blue arc if you looked into the vents at the right angle. | | |
| ▲ | aduty 26 minutes ago | parent [-] | | Brushless motors are popular now, but if you get the cheaper cordless tools they'll still have brushed motors. I have some Black & Decker 20V ones that do it. They tend to have less torque but I don't need Milwaukee or Makita tools just for diy around the house. |
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| ▲ | Bender 4 hours ago | parent | prev [-] | | Photocopiers smell like ozone when they run if anyone’s forgotten the smell Those are similar but sweeter. If I sterilize a room with UV it has a very distinct smell like nothing else aside from lightening and stun guns. I would UV the bathroom right now but then I have to vent the entire house and its 34F outside right now. | | |
| ▲ | rrr_oh_man 2 hours ago | parent | next [-] | | Side quest: Can you tell more about the UV sterilisation thing? Why do you do that? How often? Where? It seems like such a specific thing to do. | | |
| ▲ | Bender an hour ago | parent [-] | | I primarily use them in the bathroom to kill off mold and bacteria about once every 3 months. I open up the water heater closet, drawers, etc... then I fire one of them up. I've used them in other places but the more they are used the more I have to vent the house. |
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| ▲ | echelon 4 hours ago | parent | prev | next [-] | | I don't think any of you should want to be smelling Ozone. Diatomic oxygen is already a highly reactive fuel that is killing us and giving us cancer every single day. The ozone species is even more oxidative. Oxygen is how we move about the energy gradient, but it's also killing us. Ozone is worse. "Air purifiers" with ionization are probably not worth the squeeze. | | |
| ▲ | dmurray 2 hours ago | parent | next [-] | | Aside from "killing us and giving us cancer every single day", isn't "diatomic oxygen" the stuff we breathe every single minute and need to survive? I'm not normally one to miss the sarcastic or satirical posts, but this one seems oddly earnest. | | | |
| ▲ | Bender 4 hours ago | parent | prev | next [-] | | Absolutely. I vent the house after running UV lamps using a 4400 CFM air mover. I leave the house and run errands. I have 3 of these [1] They have a remote control that "arms" them and it starts beeping slow, the faster, then much faster then activates. It kills insects be destroying their lungs and entirely destroys mold, bacteria and even damages viral material. Hospitals run the same lamps in wings that they close down for sanitation. The entire area has to be 100% vented. [1] - https://www.amazon.com/AeraLight-Whole-Surface-UV-Sanitizer/... | | |
| ▲ | alfiedotwtf 3 hours ago | parent [-] | | I worked for a germaphobe, and he put one of these ozone-injecting air purifiers in our tiny office. Every morning I would walk in and it felt like I was walking into a thunderstorm from the smell. No gunpowder, just thick ozone | | |
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| ▲ | KennyBlanken 2 hours ago | parent | prev [-] | | The permissible exposure limit for ozone is 0.1 PPM. The IDLH (Immediately Dangerous to Life and Health) level for ozone is five ppm. That's half of chlorine which is 10 ppm. Most major brand air purifiers put out a very minimal amount; the ionization is beneficial because it makes the really tiny (and thus most hazardous) particles clump and fall/stick to surfaces faster. It's the offbrand units that generate lots of ozone to make people think they're "doing something", and commercial ozone generators for car/room deodorizing, that you have to be extremely careful with. Those need to be set up and then the room left for hours for the ozone to react with stuff, and then ventilated thoroughly. |
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| ▲ | LoganDark 2 hours ago | parent | prev | next [-] | | Brushed DC motors (as in some drills, toothbrushes, etc.) emit ozone. Some light switches also create ozone-producing electrical arcing if you hold them perfectly between the on and off positions, or slowly cross the midpoint. (Less easy with the newer-style, less accessible rocker switches.) | |
| ▲ | KennyBlanken 2 hours ago | parent | prev | next [-] | | The only thing you're doing by sterilizing your house like that is making your immune system weaker. Humans are built to withstand a constant assault on their immune systems. We couldn't have survived if we didn't. | | |
| ▲ | Bender an hour ago | parent | next [-] | | Don't worry I know what I am doing. | |
| ▲ | VoidWarranty an hour ago | parent | prev [-] | | Careful. The venn diagram bubble depicting your statement overlaps heavily with the anti-vaccine bubble. Its a bit naieve to claim that cleaning one's home will result in an extinction of enough microbes so as to be threatening to our immune system. | | |
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| ▲ | colechristensen 4 hours ago | parent | prev [-] | | You might be smelling the oxidation of biologicals via ozone and UV might have the same chemical effect | | |
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| ▲ | corysama 3 hours ago | parent | prev [-] | | The ozone report was specifically about space walks. The gunpowder report was about moon walks. Presumably, moonwalks would also have some ozone like the space walk did. But, maybe the burning-moon-dust gunpowder smell was a lot stronger than the vacuumed-metal/paint ozone smell. |
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