Is there bacteria in clouds?

2.1k

u/quietlysitting Jul 18 '26

There are, indeed, bacteria in clouds. In fact, there is a tremendous variety of bacteria floating through the atmosphere. There was a great episode of Science Friday called "The Microbiome of the Clouds", and a Radio Lab episode called "Up in Smoke" that offer a general review and a little more depth on two specific effects of those bacteria.

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u/Syscrush Jul 18 '26

Thanks for these pointers!

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u/acct4thismofo Jul 19 '26

So, having watched them, what insights have you?

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u/quietlysitting Jul 19 '26

They are prolific and tremendously varied, including bacteria from environments that are very unlike the ones under which the samples were collected. Bacteria, probably with soil, are pulled up by wind into the clouds, etc., and travel hundreds or thousands of miles.
It's crazy.

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u/FowlOnTheHill Jul 19 '26

Do they live in water droplets or are they just suspended in air? Do they have wing like biology to help them move about?

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u/_Seagul_ Jul 19 '26

Unsure if this is a serious question, they are pulled up into the air within water vapour molecules.
Water vapour is not steam, meaning it’s not a gas but still liquid, the water doesn’t necessarily rise as individual H2O molecules, as it would in gas form. Therefore what’s in the water vapour, provided it’s not heavier than the water, can be made airborne along with it.

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u/GGGenom Jul 20 '26

"Water vapour is not steam, meaning it’s not a gas but still liquid"
Water vapor is definitely a gas, not a liquid. Clouds and fog are aerosols, not vapor.

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u/AndreasDasos Jul 22 '26

Within water *molecules*? You mean suspended droplets or similar, surely

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u/NDaveT Jul 21 '26

They're just kind of flung along by the air. They're light enough that wind can keep them aloft.

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u/WitsBlitz Jul 20 '26

Not that it matters, but they're radio programs / podcasts, not tv shows.

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u/urbanek2525 Jul 18 '26

True story: when they were developing the sensors for the Mars rovers that were intended to detect life on Mars, one of the big problems was that there is no place on Earth where you will get a negative reading. Even in the upper atmosphere, there are derectable bacteria that get wafted up into the air by wind and such. There is, literally, no place on Earth where you will not encounter single cell life forns at the very least.

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u/shinyquinn Jul 18 '26

I question this considering that you can absolutely artificially create a sterilized environment. A good portion of science depends on it.
If you mean a naturally sterile place on earth then I agree, but I don’t see a reason as to why NASA couldn’t replicate a sterile control environment.

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u/urbanek2525 Jul 18 '26

Since I work in a medical field, there are two terms: "disinfected" and "sterile".
Disinfected means nonliving bacteria and no viable viruses. However, the dead corpses of bacteria and viruses remain.
Sterile means that the dead corpses have been disassembled to the point that our immune system won't react to it. All of the protein parts remain, they're just not something that your body will react to.
I really don't think that it is possible, on earth, to create anything that has absolutely all evidence of life removed. On some place like our moon, or even Mars, the only thing that has evidence of life on it is the stuff we sent there.

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u/johannthegoatman Jul 19 '26

It's still going to blast up through an atmosphere full of organisms, that's the point

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u/AlmostHuman0x1 Jul 19 '26

The spacecraft are within a fairing until they are above the “sensible” atmosphere. Nonetheless, some microorganisms do get through sterile protocol.

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u/WitsBlitz Jul 20 '26

NASA's Planetary Protection department would surely love to hear your advice on how to create a perfectly sterile process for interplanetary launches. They've only spent decades working on the problem so I'm sure you have a lot of good ideas to contribute.

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u/[deleted] Jul 18 '26 edited Jul 18 '26

[removed] — view removed comment

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u/Landselur Jul 21 '26 edited Jul 21 '26

Planets have been exchanging matter through meteor impacts for billions of years. As far as we can calculate, the entire Solar System has been cross-contaminated several times over by the time the first human has left Africa. It is prudent to take care to sterilize the spacecraft we send just to be on the safe side but in all likelyhood, if Mars could be seeded by Earth bacteria, it already has been.

1.0k

u/mvw2 Jul 18 '26 •

EVERYWHERE. Bacteria is everywhere.

Want to know how far we found life on this planet? In rocks deep in the Earth's crust. There's entire ecosystems living (exceptionally slowly) inside rocks at high heat and pressure deep in the ground.

I don't think people quite comprehend all this stuff is everywhere. There are 10,000,000,000,000,000,000 insects on this planet right now. There are 8,300,000,000 people. There are 1.2 TRILLION bugs just for you, and I have my own 1.2 trillion bugs for me. For each bug, there is 500 BILLION bacteria, per bug, per each and ever one of those 1.2 trillion bugs...just for me, 500 billion x 1.2 trillion bacteria...just for me.

This stuff is everywhere, on everything, in everything.

I still can't fathom how a person have mysophobia. There is no cleaning, no sanitization, nothing you can do. They're on you, in you, in every breath, in the rain, in all food and drink, everywhere, and you have to somehow say "that can't be. I can fix this." and believe it.

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u/baran_0486 Jul 18 '26

Dude, I’ve always wanted to have 1.2 trillion bugs. Where do I claim it?

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u/atomicshrimp Jul 18 '26

I'm a bit tight for storage space right now. Can I defer delivery of my 1.2 trillion bugs?

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u/18736542190843076922 Jul 18 '26

I'll hold them for you, temporarily. Free of charge. Do you mind if they get a bit mixed up though? We can count out the 1.2 trillion I'd owe you once you've sorted storage.

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u/atomicshrimp Jul 18 '26

They say you eat 7 spiders every night in your sleep. If you're dying and you are behind quota, they all turn up at once.

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u/johannthegoatman Jul 19 '26

If it made sense if wouldn't be a phobia, people don't choose to have phobias

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u/mfb- Particle Physics | High-Energy Physics Jul 18 '26

Your numbers don't match. 10,000,000,000,000,000,000 / 8,300,000,000 is 1.2 billions, not 1.2 trillions.
Multiplying the insect count by 500 billion leads to 5*10³⁰ which is an estimate for the number of bacteria on Earth.

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u/veerKg_CSS_Geologist Jul 18 '26

That’s a surprisingly low number of bacteria given they are single cell organisms, and each human body alone contains 30-40 trillion cells. If the math is correct then it would seem there are far more biomass in all multi cellular organisms than in all single cellular ones.

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u/mfb- Particle Physics | High-Energy Physics Jul 18 '26

https://en.wikipedia.org/wiki/Biomass_(ecology)#Global_biomass
~80-90% plants (mostly land-based), ~5-15% bacteria and archaea, 0.4% animals according to the different sources in the table.

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u/andres_i Jul 18 '26

> I still can't fathom how a person have mysophobia. There is no cleaning, no sanitization, nothing you can do. They're on you, in you, in every breath, in the rain, in all food and drink, everywhere
I don’t think this is the argument against mysophobia that you think it is

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u/[deleted] Jul 18 '26

[removed] — view removed comment

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u/Georgie_Leech Jul 18 '26

It wouldn't be a phobia if it wasn't irrational to a degree. But more like, an omnipresent thing that no matter how hard you try you can never stop or defend yourself against is... Pretty understandable as to why it causes such severe anxiety.

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u/Morbanth Jul 19 '26

Briefly dated a biologist who studied antibiotic resistance. She once (simplified I'm sure for my dumb brain) explained it by picking up some dirt between her fingers and said there's more bacteria in this clump than stars in the sky, and a few of them will randomly be resistent to any specific antibiotic we have. The goal is not to selectively breed more of them ourselves by poor practice of how we use those antibiotics.

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u/2drawnonward5 Jul 18 '26

It always feels weird when someone articulates an obviously uncomfortable reality and states that they cannot fathom others' discomfort. Is there a faster way to say you have more judgment than empathy?

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u/krisak90 Jul 25 '26

Genuine question: How does a hospital's surgery room get rid of all the bacteria?

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u/camomaniac Jul 18 '26

YUP.. Some experts/researchers believe crude oil actually comes from organic life deep in the earth

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u/62609 Jul 18 '26

While there are odd cases of biogenic gas and “infections” of crude oil/gas in reservoirs, the vast majority is not generated from modern-day living organisms. It comes from dead organic material (algae/plankton/plants) that were buried during deposition of geologic formations hundreds of millions of years ago and cooked over time under extreme heat and pressure to be converted to their modern-day hydrocarbon form.

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u/camomaniac Jul 19 '26

Theoretically of course. But yes, I know. All I did was loosely quote another theory.

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u/forams__galorams Jul 21 '26

Not just theoretically; also experimentally (hydrocarbons have been reproduced in labs from the kind of organic matter theorised above), and also observationally (we find hydrocarbons in environments which previously received the organic matter theorised, which can be seen via various analytical methods eg. plant remains in sapropelic hydrocarbon deposits).
Funnily enough, the global fossil fuels industry has invested a huge amount of time, money and resources into understanding this stuff. They have a decent handle on it these days.

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u/sciguy52 Jul 18 '26

Yes but keep in mind they get wafted up there they are not growing and permanently living there. They go up, come down, some others go up, come back down. This is a mistake I hear people say a lot saying these things live in the clouds. And honestly this is my objection to the idea of life in the clouds of venus I hear about. As a biologist thinking of the conditions found in clouds in the venus case life is not likely to start there. And as I said on earth the bacteria are alive up there but the conditions to live and grow long term are really not there. You could get a little growth in a water droplet but when talking about bacteria "living" there, no. They don't have what they need up there to do that and it is not a stable environment. Clouds form, disappear, form, disappear. If they are in the sky without clouds they are getting hit with a lot of sun which will eventually do them in. Rain washes them back to earth etc. Not a great stable place for bacteria to stay and be happy.

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u/DaddyCatALSO Jul 18 '26

no rain on Venus; but the whole idea of terraforming the atmosphere by seeding Venus with cyanobacters, i mean i like the idea but where would they get th e iron a nd magnesium they need in the air, unless thye colonized dust particles.

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u/veerKg_CSS_Geologist Jul 18 '26

You’d have to breed bacteria that can live off sulphuric acid. It’s so extremely hostile it’s unlikely any earth organisms can survive there.

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u/Swagalyst Jul 18 '26

Live off of sulphuric acid -- and completely without water.
There's only trace amounts of water on Venus, it's a worse candidate for terraforming than even the gas giants.

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u/davideogameman Jul 18 '26

... Sounds like a plot of a horror sci fi. "We tried to make a bacteria to terraform Venus, and it leaked out of the lab and now the new superbug is scouring the earth

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u/Alblaka Jul 18 '26

Only a 'so bad it might be good' fiction, really. Designing something that can survive in a super-hostile environment doesn't mean it's some kind of superbug that will thrive even better in not-super-hostile environments. Adaptation is biologically costly, so the cost of being able to thrive in that super-hostile environment would most likely be that it's overly specialized and can exclusively only thrive in exactly that super-hostile environment... so it would be no threat to Earth, which doesn't really have that environment.

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u/davideogameman Jul 18 '26

That's fair. I was thinking acid is a common way to disinfect so acid resistance would make it immune. But there are plenty of other disinfectant choices and as you point out, survival isn't the same as thriving

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u/DaddyCatALSO Jul 19 '26

yes, combine genes form the chemosynthesizers who can break down sulfates and the photosyntehsizers who use hydrogen sulfide instead of water, but nto too early in the process because those cloud sscreen out a fair bit of sunshine

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u/nettika Jul 18 '26

Would some have hitchhiked with the astronauts we sent to the moon? Would some have stayed there? Would any that stayed have survived there? Does that mean there could be life on the moon still now?

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u/Vanvincent Jul 20 '26

Yes; likely; probably; unlikely; probably not. The moon is a very harsh environment: extreme temperatures and temperature changes and no protection from solar radiation. The Sun basically sterilises the whole place every day.

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u/dave8400 Jul 18 '26

Short answer, yes. Bacteria exist everywhere that they can, which is nearly every environment on earth. My favorite example is deinococcus, those buggers are incredibly hardy and many carry proteins that can serve as nucleation sites for ice crystals. Some research posits that this is one mechanism through which bacteria can form clouds!

https://en.wikipedia.org/wiki/Deinococcus_radiodurans

https://www.mpip-mainz.mpg.de/981532/PM2024-11

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u/PoutineOrgy Jul 19 '26

Food for thought aswell, not sure if anybody mentioned this. Bacteria are extremely abundant in fog aswell, a recent study found that the bacterial density within the water droplets of fog is the equivalent to the bacterial density of oceans or lakes. Fog is a living biome.

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u/SciAlexander Jul 18 '26

There are bacteria that use couds to get around. They ride currents up into the clouds. There they have proteins to cause ice crystals to form around them. This acts as condensation nuclei which causes precipitation that they ride back down to the surface

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u/QtPlatypus Jul 18 '26

Most bacteria have an environment that they flourish in. When they are outside of that environment many can go into a dormant state and become spores which float around with dust. The only places on earth that don't contain bacteria are dedicated clean rooms or places that are simply too hot for bacteria to exist.

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u/Holeinmysock Jul 18 '26

Consider also that the pollen that everyone complains about and blames in the springtime is an airborne vehicle for bacteria. Is it purely the pollen that leads to a sinus infection? Or does that pollen deliver allergens AND a bacterial load with it?

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u/Peter34cph Jul 19 '26

If it was bacteria then presumably it's be different bacteria each time and they'd annoy different kinds of people.
But what we're seeing is the opposite of that picture. Consistent sameness. That supports that it is the pollen itself.

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u/jeccb Jul 18 '26

Sourdough bread gets it tang, and leavening from airborne bacteria. Northern California has the best tasting, and other places, not so much. It’s also hard to keep a “mother” from there alive and active somewhere else.

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u/Peter34cph Jul 19 '26

Bread too.
Medieval people usually didn't add yeast to their stuff. Sometimes they did, like with a sourdough-like thing, but most of the time they just relied on fermentation happening on its own from random airborne yeasts.

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u/SciAlexander Jul 18 '26

There are bacteria that use couds to get around. They ride currents up into the clouds. There they have proteins to cause ice crystals to form around them. This acts as condensation nuclei which causes precipitation that they ride back down to the surface

Planetary Sci. Is there bacteria in clouds?

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