1 00:00:01,920 --> 00:00:04,280 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio, 2 00:00:07,680 --> 00:00:11,080 Speaker 1: Hey brain Stuff, Lauren vog Bomb. Here, we all know 3 00:00:11,160 --> 00:00:15,360 Speaker 1: that space is empty. Most of space is completely absent 4 00:00:15,400 --> 00:00:19,720 Speaker 1: of anything, not dust, not planets, nor Sun's, not even air. 5 00:00:21,640 --> 00:00:24,360 Speaker 1: So why do many of the people who have been 6 00:00:24,400 --> 00:00:27,360 Speaker 1: to space and spend time in it report that space 7 00:00:27,680 --> 00:00:32,280 Speaker 1: has a smell? It turns out that space does smell, 8 00:00:32,520 --> 00:00:35,760 Speaker 1: and our solar system in fact, has a very particular scent. 9 00:00:36,520 --> 00:00:39,320 Speaker 1: This is likely the result of several factors, but all 10 00:00:39,360 --> 00:00:42,720 Speaker 1: are clear. Our corner of the universe is kind of stinky. 11 00:00:44,960 --> 00:00:48,240 Speaker 1: While no astronaut has ever been unwise enough to unclasp 12 00:00:48,320 --> 00:00:51,000 Speaker 1: and remove their helmet in the near vacuum of space, 13 00:00:51,400 --> 00:00:56,360 Speaker 1: many have reported having experienced sense up there upon their return. Specifically, 14 00:00:56,560 --> 00:01:00,640 Speaker 1: many astronauts report different smells in the airlock after participating 15 00:01:00,720 --> 00:01:06,119 Speaker 1: in spacewalks. American astronaut Don Petite described it in this 16 00:01:06,160 --> 00:01:09,600 Speaker 1: way after returning from NASA's Expedition six to the International 17 00:01:09,600 --> 00:01:13,399 Speaker 1: Space Station in two thousand three. A quote, The best 18 00:01:13,400 --> 00:01:17,640 Speaker 1: description I can come up with is metallic, a rather pleasant, sweet, 19 00:01:17,680 --> 00:01:21,600 Speaker 1: metallic sensation. It reminded me of my college summers, where 20 00:01:21,600 --> 00:01:24,360 Speaker 1: I've labored for many hours with an arc welding torch 21 00:01:24,480 --> 00:01:28,240 Speaker 1: repairing heavy equipment for a small logging outfit. It reminded 22 00:01:28,280 --> 00:01:31,840 Speaker 1: me of pleasant, sweet smelling welding fumes. That is the 23 00:01:31,880 --> 00:01:35,600 Speaker 1: smell of space. Other astronauts have described it in similar 24 00:01:36,240 --> 00:01:40,280 Speaker 1: varying ways, burning metal, a distinct odor of ozone and 25 00:01:40,360 --> 00:01:45,839 Speaker 1: acrid smell, walnuts and brake pads, gunpowder, and even burnt 26 00:01:45,880 --> 00:01:50,440 Speaker 1: almond cookie a much like wine, connoisseurs may smell something 27 00:01:50,480 --> 00:01:53,480 Speaker 1: a bit different from the same bottle. Astronaut reports differ 28 00:01:53,560 --> 00:01:56,800 Speaker 1: slightly in their scent notes, but have one thing in common, 29 00:01:57,280 --> 00:02:02,680 Speaker 1: a burnt smell. So what might explain why space smells burnt? 30 00:02:03,320 --> 00:02:07,600 Speaker 1: There are two possible explanations. OH one hypothesis relates to 31 00:02:07,640 --> 00:02:10,799 Speaker 1: the process that occurs in the airlock as astronauts return 32 00:02:10,919 --> 00:02:14,000 Speaker 1: from space to the I, S, S, or whatever spacecraft 33 00:02:14,040 --> 00:02:19,160 Speaker 1: they call home temporarily during repressurization. The chemical reaction of 34 00:02:19,200 --> 00:02:23,200 Speaker 1: oxidation occurs atoms of oxygen in space attached to the 35 00:02:23,240 --> 00:02:26,919 Speaker 1: astronaut suit and flowed in during the depressurized time when 36 00:02:26,919 --> 00:02:30,480 Speaker 1: the airlock is open, and then combined to form atmospheric 37 00:02:30,520 --> 00:02:35,280 Speaker 1: oxygen or O two. This process is similar to combustion 38 00:02:35,600 --> 00:02:39,360 Speaker 1: without the flame and smoke and smells similar to which 39 00:02:39,440 --> 00:02:44,280 Speaker 1: might explain the smoky, charred odor that astronauts report. A 40 00:02:44,360 --> 00:02:49,480 Speaker 1: second hypothesis relates to stellar explosions, that is, dying stars. 41 00:02:50,120 --> 00:02:52,480 Speaker 1: Though we've only been studying the night sky for a 42 00:02:52,520 --> 00:02:56,560 Speaker 1: few millennia, the universe is some thirteen point seven billion 43 00:02:56,639 --> 00:02:59,480 Speaker 1: years old. Our Solar system is estimated to be about 44 00:02:59,520 --> 00:03:02,520 Speaker 1: four and a half billion years old. This means that 45 00:03:02,600 --> 00:03:06,359 Speaker 1: for literally billions of years before Solar System ever formed, 46 00:03:06,840 --> 00:03:11,720 Speaker 1: stars were being born and dying across the universe. When 47 00:03:11,760 --> 00:03:14,919 Speaker 1: stars die, it tends to be a dramatic affair, and 48 00:03:15,120 --> 00:03:21,240 Speaker 1: this bombastic process creates compounds called polycyclic aromatic hydrocarbons or 49 00:03:21,360 --> 00:03:24,519 Speaker 1: p h s. P a h s are present throughout 50 00:03:24,520 --> 00:03:27,560 Speaker 1: the Solar System, including here on Earth. They can be 51 00:03:27,600 --> 00:03:31,920 Speaker 1: found in some foods, in coal and oil, among other materials. 52 00:03:32,520 --> 00:03:36,080 Speaker 1: They also occur when coal, tobacco, wood, meat, and other 53 00:03:36,120 --> 00:03:40,720 Speaker 1: substances are burned. Perhaps part of the reasons space has 54 00:03:40,760 --> 00:03:44,520 Speaker 1: a distinctly burnt and charcoal smell is because it, like 55 00:03:44,600 --> 00:03:47,680 Speaker 1: a grill on a summer evening, is emitting smelly p 56 00:03:48,080 --> 00:03:52,720 Speaker 1: H is outside of our Solar system it's not as stinky. 57 00:03:53,120 --> 00:03:56,160 Speaker 1: Other parts of the universe do have compounds and elements 58 00:03:56,200 --> 00:03:59,840 Speaker 1: that create different smells, though't no human is likely to 59 00:04:00,040 --> 00:04:03,800 Speaker 1: or take a big whiff to confirm, but just for example, 60 00:04:04,160 --> 00:04:08,240 Speaker 1: the dust cloud Sagittarius B two has a high concentration 61 00:04:08,280 --> 00:04:11,680 Speaker 1: of ethel formate, which is the compound that gives raspberries 62 00:04:11,720 --> 00:04:15,520 Speaker 1: and rum part of their distinctive odors. So if you 63 00:04:15,640 --> 00:04:18,560 Speaker 1: love a good raspberry dacory, that maybe the corner of 64 00:04:18,560 --> 00:04:28,240 Speaker 1: the universe for you. Today's episode is based on the 65 00:04:28,320 --> 00:04:31,039 Speaker 1: article what does space Smell Like? On how stuff works 66 00:04:31,080 --> 00:04:34,279 Speaker 1: dot Com written by Valerie Cymac. Brain Stuff is production 67 00:04:34,320 --> 00:04:36,279 Speaker 1: of by Heart Radio in partnership with how stuff works 68 00:04:36,320 --> 00:04:39,320 Speaker 1: dot Com, and it's produced by Tyler Clang. Four more 69 00:04:39,360 --> 00:04:42,040 Speaker 1: podcasts from my heart Radio visit the i heart Radio app, 70 00:04:42,120 --> 00:04:45,000 Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.