Methane Explosion on Asteroid?

[Janet]

Hi! I am almost finished with a sci fi novel, the last two chapters, one of which involves a rescue on a mining asteroid. Could someone weigh in an whether a methane explosion might be able to take place in an interior work face in the asteroid? If so, I can just use details from the Sago mine disaster, for one source.

Thank you so much for being here right when I need you!!

[mythic_fci]

It depends. Any explosive chemical usually needs a pressurized oxygen environment to function well (see Apollo 1 fire), and needs a spark powerful enough. If the interior mining section you are referring to is pressurized with pure O2, has faulty (sparking) equipment, and has a methane leak of some sort (or one way for methane to get into the atmosphere), it might work. Keep in mind that I'm not a chemist though, so I may be wrong.

[Cirocco]

depends. From an asteroid I think that's pretty unlikely. Methane is usually a product from either geological of biological processes, and asteroids (which are either solid or loosely held aglommerations of rubble) don't really have either. It's possible an asteroid might contain pockets of methane, but for one to have large enough pockets to be able to mix with air and cause a catastrophic explosion seems extremely unlikely.

Now, comets on the other hand are a different story. Comets are often described as "dirty snowballs". They are composed of (usually) mostly water ice, frozen gasses and quite a bit of carbon-based compounds. It is far more likely for a comet to have pockets of hydrocarbons such as methane or other combustible/explosive gasses (ethane, ethanol, HCN, etc.). If your comet is big enough, I don't think it's unthinkable that there may be pockets of explosive gasses large enough to cause an explosion if mixed with oxygen or another oxidizer.

This of course does assume that said comet is being mined and that an artificial, breathable atmosphere is in place.

Edited August 22, 2014 by Cirocco
some clarification

[Javster]

As said above, remember fire (and therefore explosions) needs 3 things: ignition, fuel, and oxygen.

[Kialar]

As said above, remember fire (and therefore explosions) needs 3 things: ignition, fuel, and oxygen.

ignition, reducer and oxidizer, if I may interfer.

And oxidizer must not be oxygen.

For example hydrogen an chlorine make very fine detonations in absence of oxygen.

But to OP: It is possible for an astroid to contain significant amouts of solid methane, wich may sublimate and react with an oxidizer.

The question is: what oxidizer is there? Is the asteroid mine pressurized and under breathable atmosphere? If yes a detonation after a sublimation might occur/is thinkable.

-Kia

[Cirocco]

ignition, reducer and oxidizer, if I may interfer.

And oxidizer must not be oxygen.

For example hydrogen an chlorine make very fine detonations in absence of oxygen.

yup, correct.

But to OP: It is possible for an astroid to contain significant amouts of solid methane, wich may sublimate and react with an oxidizer.

The question is: what oxidizer is there? Is the asteroid mine pressurized and under breathable atmosphere? If yes a detonation after a sublimation might occur/is thinkable.

-Kia

Eeeeeeeeeerh... For an asteroid to contain large enough amounts of frozen methane seems unlikely. If it does, it more than likely would also contain large amounts of other volatile ices and would resemble a comet more than an asteroid. Asteroids tend to be more rocky.

FCISuperGuy brought up an interesting point though: if it's an industrial accident you might actually be able to sidestep the problem entirely. Rather than blowing up a naturally occuring resource such as methane, you might just as well blow up a fuel supply or something else that was brought along by the inhabitants. Don't know if that would fit with the rest of your story of course.

[Kialar]

Eeeeeeeeeerh... For an asteroid to contain large enough amounts of frozen methane seems unlikely. If it does, it more than likely would also contain large amounts of other volatile ices and would resemble a comet more than an asteroid. Asteroids tend to be more rocky.

That depends on the origin of the asteroid. And of the line one draws between comets and asteroids (wich is controverse among astronomers).

But I agree, it is unlikely for an asteroid to contain large amounts of hydrocarbons, but not impossible from a astrochemical point of view.

FCISuperGuy brought up an interesting point though: if it's an industrial accident you might actually be able to sidestep the problem entirely. Rather than blowing up a naturally occuring resource such as methane, you might just as well blow up a fuel supply or something else that was brought along by the inhabitants. Don't know if that would fit with the rest of your story of course.

Yep. I just had a similar idea, like Acetylene for welding purposes.

EDIT: Or a container with Hydrazine.

[Kasuha]

There is almost certainly nothing explosive on asteroids themselves. All chemical compounds in them are near their energetical optimum for millenia. There might be methane on asteroids but there is nothing the methane would react with violently.

A methane explosion could occur, if the asteroid mining company was unresponsible enough to carve their living quarters directly into the body of the asteroid without proper insulation. In such case, the methane could seep from the asteroid's ice and create explosive mixture. What's way more likely in that case is however explosive decompression caused by cracks violently appearing in the ice and letting pressurized air out into free space.

Assuming the company is not that unresponsible, the only way how to get an explosion in living quarters (where we can expect high enough concentrations of oxygen or other compounds allowing methane to cause explosion) is for someone to collect methane in a container and transport to those living quarters (or perhaps storage space). I would expect, though, the company to use airless storage.

Mining site would be, I assume, in vacuum. It is impossible for methane to explode there chemically. What is possible, though, is collection of methane (or more likely just water) in a cavernous opening and heated up e.g. by the drilling equipment malfunction. That would not mean chemical explosion, rather explosion caused by violent release of the collected pressure but results might be very serious in such cases as well.

[Kialar]

That would not mean chemical explosion, rather explosion caused by violent release of the collected pressure but results might be very serious in such cases as well.

Yes. A rather violent decompression sounds more logical in such an environment.

[Cirocco]

Alright, I've been doing some thinking on this on the ride back home from work. Here's what I came up with:

as mentioned before, while the conditions for a chemical explosion with methane or another combustible gas is possible, a violent decompression or some other form of physical explosion is more likely unless the miners are very, very careless and thoughtless in their base construction and operations.

However...

Kialar's comment regarding a hydrazine explosion caught my interest. Hydrazine is commonly used as rocket fuel, often in monopropellant engines. However, pure hydrazine is NASTY. It is dangerously unstable, incredibly toxic (lethal dose lies somewhere in the parts per million range) and some very nasty long term effects even in sub-lethal doses. Imagine an explosion in your hydrazine storage on an asteroid base. Not good.

And it gets better. My interest being piqued, I looked up the properties of hydrazine. A lot of info is readily available on the wikipedia page, some other info I remembered from my classes back at university.

Hydrazine is, as mentioned, unstable. When exposed to a metal catalyst (more precisely, iridium compounds) it violently reacts with itself. So violently in fact, that in a rocket engine it heats up the reaction chamber to 800°C in milliseconds. Now, iridium is an extremely rare metal here on earth. In fact, quite a bit of the iridium we nowadays use in catalysts doesn't actually originate from earth. It comes from, you guessed it, impacted asteroids. Now of course iridium in its raw form won't be as finely dispersed as it would be on a catalyst specifically made for the job, but it can still be a huge pain.

So say you store your rocket fuel outside of the base. Seems sensible right? don't want to risk something that toxic getting into the enclosed atmosphere. Now say you spring a leak in one of the cannisters. Hydrazine starts venting into space, encounters a patch of asteroid with a larger amount of exposed iridium.... Next thing you know VERY bad things are happening.

I'm not sure if this will help the OP in any way, it might be too technical or far-fetched, but I just wanted to share.

[Kialar]

Cirocco, you deserve a reputation point for this idea.

A star from me.

[Janet]

depends. From an asteroid I think that's pretty unlikely. Methane is usually a product from either geological of biological processes, and asteroids (which are either solid or loosely held aglommerations of rubble) don't really have either. It's possible an asteroid might contain pockets of methane, but for one to have large enough pockets to be able to mix with air and cause a catastrophic explosion seems extremely unlikely.

Hello! According to this link, methane is present in abundance on common asteroids:

http://www.iom3.org/news/mine-sky-harvesting-asteroids-metals

[Janet]

There is almost certainly nothing explosive on asteroids themselves. All chemical compounds in them are near their energetical optimum for millenia. There might be methane on asteroids but there is nothing the methane would react with violently.

A methane explosion could occur, if the asteroid mining company was unresponsible enough to carve their living quarters directly into the body of the asteroid without proper insulation. In such case, the methane could seep from the asteroid's ice and create explosive mixture. What's way more likely in that case is however explosive decompression caused by cracks violently appearing in the ice and letting pressurized air out into free space.

Assuming the company is not that unresponsible, the only way how to get an explosion in living quarters (where we can expect high enough concentrations of oxygen or other compounds allowing methane to cause explosion) is for someone to collect methane in a container and transport to those living quarters (or perhaps storage space). I would expect, though, the company to use airless storage.

Mining site would be, I assume, in vacuum. It is impossible for methane to explode there chemically. What is possible, though, is collection of methane (or more likely just water) in a cavernous opening and heated up e.g. by the drilling equipment malfunction. That would not mean chemical explosion, rather explosion caused by violent release of the collected pressure but results might be very serious in such cases as well.

Thanks to all, but I think I have gotten what I need right here. Originally I had thought to have the working face pressurized (in fiction, it doesn't cost much! : ) ) but this information enables me to have the accident happen in the living quarters, giving many more elements for drama insofar as more characters can be affected than would be believable in a working mine. I have already presented the company as irresponsible and greedy, and the living quarters as interior. So I think I've got the elements here for a great chapter. I can still borrow heavily from the Sago Mine disaster. Thanks really, kind of you to help me!

[Janet]

Wait! I lied! There's one more part I don't have yet! Okay, to start, am probably staying with methane and the scenario they built the living quarters interiorally and cheap so that there's an eventual contact and spark (the above persuasive comments notwithstanding!). That minimizes the need for technical narrative--people would be familiar with the concept etc and the conditions that ensue following such an explosion--like any mine on Earth. But beyond that I need something else for the plot. I have good guys, rescuers, coming which the asteroid mine management BLOCKS from rescuing the trapped, so that a thrilling fire fight ensues. But, why would management do that? I was considering something like, they'd rather not risk the expensive equipment (let's say right outside the blocked area) to another explosion. But can you think of something better? Not that I'd put it past a real management team to sacrifice human lives to capital. But the equipment thing is so bald.

[Cirocco]

Hello! According to this link, methane is present in abundance on common asteroids:

http://www.iom3.org/news/mine-sky-harvesting-asteroids-metals

Hmm. Unless I misread, that article only mentions that C-call asteroids (which are the most common ones, certainly) can be mined for, amongst other things, methane. Doesn't say which concentrations a single asteroid usually carries or in what form. I just figured what with methane having such a low melting and boiling point that it would be among the first substances to boil off if exposed to sunlight or heat.

That being said I am for form an expert on astronomy, could be that asteroids do contain larger pockets of methane ice that somehow doesn't get boiled off (I wonder how though... to google!). Again, I'm no expert on asteroids, I'm more of a chemistry person.

Happy we could be of assistance though.

EDIT: aaaaand I found the answer to my question. It's mostly just semantics as Kialar suggested . It appears that the difference between comet and asteroid is simply whether or not it has an active coma. Small celestial bodies (which apparently is the common denominator for the two) come in a wide range of compositions going from almost no volatiles to tons of them and everything in between those two extremes. The difference between comet and asteroid is completely artificial.

learn something new everyday

Edited August 22, 2014 by Cirocco

[peadar1987]

Wait! I lied! There's one more part I don't have yet! Okay, to start, am probably staying with methane and the scenario they built the living quarters interiorally and cheap so that there's an eventual contact and spark (the above persuasive comments notwithstanding!). That minimizes the need for technical narrative--people would be familiar with the concept etc and the conditions that ensue following such an explosion--like any mine on Earth. But beyond that I need something else for the plot. I have good guys, rescuers, coming which the asteroid mine management BLOCKS from rescuing the trapped, so that a thrilling fire fight ensues. But, why would management do that? I was considering something like, they'd rather not risk the expensive equipment (let's say right outside the blocked area) to another explosion. But can you think of something better? Not that I'd put it past a real management team to sacrifice human lives to capital. But the equipment thing is so bald.

Maybe they're paranoid about people robbing their extracted minerals, or industrial espionage? You could even work a reference to this in earlier in the novel if you don't mind a rewrite. Have a small section where a spacecraft in distress tries to come to the asteroid for help, but is driven off by the company, setting up things for later?

[Cirocco]

Wait! I lied! There's one more part I don't have yet! Okay, to start, am probably staying with methane and the scenario they built the living quarters interiorally and cheap so that there's an eventual contact and spark (the above persuasive comments notwithstanding!). That minimizes the need for technical narrative--people would be familiar with the concept etc and the conditions that ensue following such an explosion--like any mine on Earth. But beyond that I need something else for the plot. I have good guys, rescuers, coming which the asteroid mine management BLOCKS from rescuing the trapped, so that a thrilling fire fight ensues. But, why would management do that? I was considering something like, they'd rather not risk the expensive equipment (let's say right outside the blocked area) to another explosion. But can you think of something better? Not that I'd put it past a real management team to sacrifice human lives to capital. But the equipment thing is so bald.

hmm... Perhaps the management would want to cover up the fact that they skimped on worker safety in order to cut costs? If a rescue team flies in, they'll most likely going to want to know how said explosion happened, or they'll just realise it straight away once they board and see the state of the infrastructure.

Of course that plotline only works if said company actually cares about their image. If it is widely known that they don't care about worker safety but are simply too powerful to be called out on it, then this suggestion wouldn't make a lot of sense.

[TimePeriod]

In my eyes, any kind of pressurized vapour/air would be pretty dangerous in a zero-G environment.

[Kasuha]

But, why would management do that?

Management might be blocking access for rescuers in order to cover its illegal or unlawful activities. Such as nonexistant safety standards, bad conditions, employing slaves or criminals, hiding wanted criminals, etc, etc. Or the ..... mining site might be illegal. Not very original, though.

Hmm. Unless I misread, that article only mentions that C-call asteroids (which are the most common ones, certainly) can be mined for, amongst other things, methane. Doesn't say which concentrations a single asteroid usually carries or in what form. I just figured what with methane having such a low melting and boiling point that it would be among the first substances to boil off if exposed to sunlight or heat.

I found this:

http://www.planetaryresources.com/asteroids/composition/

Asteroids also contain more common metallic elements such as iron, nickel, and cobalt, sometimes in incredible quantities. In addition to water, other volatiles, such as nitrogen, CO, CO2, and methane, exist in quantities sufficient to warrant extraction and utilization.

It does not look like a scientific site, though, and it is the only reference I found that mentions it. In any case, we're discussing fiction.

[Mesons]

Asteroid composition depends mostly on distance from the sun over the time in which it formed--most asteroids are collections of dust and gases stuck together by collisions. The farther from the sun, the lower the temperature of the dust and gas, and the lower the temperature, the more volatile the makeup of the dust and gas that sticks to your growing asteroid. Lots of asteroids contain ice, and as methane is a very simple, light molecule, it makes up a large amount of non-H, non-He constituents of the gas giants and their moons with atmospheres (especially Titan). I don't see it as far-fetched at all for asteroids (especially those forming farther out and migrating into the asteroid belt or elsewhere) to contain a large amount of methane.

I do think that Cirocco's hydrazine slant has a lot of merit, though, and it might be easier to come up with a logical accident with that than with mining methane. Though if the methane found in the asteroid is relatively concentrated, it would be in ice form, so there's a few angles you could take with expansion of the methane from sublimation, improper storage of the ice, etc. Despite the plausibility of hydrazine problems, leaking the gas to space would not result in high enough concentrations to ignite in vacuum, unless it was kept together, i.e. leaking into an enclosed pocket between the tank and an iridium-rich surface. There's lots of things you can do here, Janet.

Be sure to post about your completed work on the forums when you have finished! I would probably give it a read!

[Vanamonde]

Moved to Science Labs.

[Janet]

In my eyes, any kind of pressurized vapour/air would be pretty dangerous in a zero-G environment.

Why???? I mean, why worse than an environment with gravity?

[Janet]

hmm... Perhaps the management would want to cover up the fact that they skimped on worker safety in order to cut costs? If a rescue team flies in, they'll most likely going to want to know how said explosion happened, or they'll just realise it straight away once they board and see the state of the infrastructure.

Of course that plotline only works if said company actually cares about their image. If it is widely known that they don't care about worker safety but are simply too powerful to be called out on it, then this suggestion wouldn't make a lot of sense.

That's what I meant about using methane as the bad guy, because it requires so much less explanation to readers, being common enough in disasters here on Earth.

Good point about image control being central, needing to be built in. I have been developing that idea throughout--they have little security, little fall back protection--there's a better word, but I forget it at the moment, no 'safe rooms,' individual survival suits, etc. etc.--on the brand new colony, because they're trying to build an image of a 'Perfect Mankind in Space.' That is, no accidents ever, no worries ever. Like Apple. They think that will attract the scarce young labor force. (They try to build that same image here on Earth but we always mess it up, haha.)

Cirocco, you've sure got a great fiction sense! I can re-write a lot, haven't submitted it to the editor yet. Thank you so much!

[crubs]

The question I'd have about methane is, what exactly is your company using it for?

[Janet]

Oh, Mesons, thanks!! But it's two hundred pages, dear heart! I'll come post a link where you can get it, though, when it's done. It's called Run. That's not very original but the rest of it is. I only have two chapters left, this fight scene, and the very last scene where the good guys pull into their hidden asteroid in the Oort Cloud to build a new world not based on modern society, especially the modern economy, at all.

I think I used science in a pretty creative way in one scene. When the good guys rescue the miners and split, they are pursued. There's a little gun play but both pursuers and pursued are interrupted by a Solar Weather Warning that an unanticipated CME of catastrophic proportions is headed straight for them. The good guys are passing an asteroid which happens to be a water asteroid, common in space--a source of oxygen, water, and fuel. They analyze it quickly and just at the right second pulverize it with their lasers and plunge into the steam, and are saved, but the pursuers, not so much. Just like Exodus only not. (Water in any form protects from radiation--God bless Google.) Please don't tell me it's impossible, I'm only going for plausible!