True, but the odds of finding free alkali metals on a planet that’s existed for more than five minutes can’t be at all high.
Yes, lots of metals will burn, including plain old iron. Except all these metals require an oxidizer to burn. Lots of asteroids contain unoxidized metals, but those metals will never burn unless they come in contact with an oxidizer.
And Blake is right that volcanoes on Earth often bring unoxided materials into contact with air, in which case those materials can burn like crazy. But without the oxygen in the air those materials will not burn, no matter how hot they get. When a volcano on Io brings hot unoxided sulfur to the surface that sulfur won’t burn like it would on Earth, because there’s no oxygen for it to combine with.
For fire to exist at any place in the universe we need the three parts of the fire triangle–fuel, oxidizer, heat. The hard part is getting all three parts of the triangle together. And once the reaction is complete, the fire is now over. This means that even on Earth which is covered with biologically produced fuel and soaked with oxidizer fire is a fairly uncommon phenomenon.
Note quite correct, if we are also considering hypothetical exoplanets. A so-called ocean planet, that is, a waterworld with a very thick layer of water and an ice mantle, could develop a very thick oxygen-rich atmosphere from photodissociation alone. However there would be little or no available fuel on a waterworld, so the normal situation would be reversed there.
No-one knows for sure if ocean planets are common in the universe, but judging from the observed range of density seen in the planets detected so far, they may well be quite widespread. So planets where a shortage of fuel (rather than a shortage of oxygen) prevents fire may be commonplace.
I recently read a Facebook post stating that fire and liquid water only exist on Earth and no where else in the universe. That is a very bold statement considering that the universe has an infinite number of stars and planets and the fact that we have only gone as far as our moon and that was 50 yrs ago. Statistics, physics, science and logic support the fact that there are millions of planets just like Earth in the universe that could not only have fire and water but be capable of supporting life! Hell one of Jupiter’s moons has oceans under its ice surface layer. Its ridiculous to think that Earth is the only planet in the entire universe to support fire, water and life! We are not that special we just got lucky!
I found these:
You’re almost certainly correct that the Facebook post was wrong. So I hope you told *them *so, rather than coming here to tell us. Believe me when I say that everybody here is already well aware that the internet is full of idiots spouting nonsense.
Was the Facebook post from some kind of religious group? Jesus-y, maybe?
You people who are saying that you need an oxygen atmosphere to support flame are – surprisingly – wrong. Despite the fact that flame is an “oxidizing” reaction, you don’t actually need oxygen.
As fans of old science fiction are aware, you can burn things in a chlorine atmosphere. Not simply an atmosphere that contains chlorine in addition to oxygen, but an atmosphere of pure chlorine will support flame. I used to have an experimental procedure for doing this in my old chemistry experiment bookm, and it’s an impressive laboratory demonstration. Old SF writers used this as justification for “chlorine-based life”. Science and Scxience Fiction writer Hal Clement came up with the design for a chlorine-atmosphere world he called “Bleachworld”. He did paintings for it, but as far as I know never wrote a story set on that chlorine-atmosphere world.
https://search.yahoo.com/search;_ylt=A0LEV2H3KRBVLrIAsXdXNyoA;_ylc=X1MDMjc2NjY3OQRfcgMyBGZyA3lmcC10LTI1MgRncHJpZANGdE4yRVdvV1NfMjB0YVdqMFpvZENBBG5fcnNsdAMwBG5fc3VnZwM0BG9yaWdpbgNzZWFyY2gueWFob28uY29tBHBvcwMwBHBxc3RyAwRwcXN0cmwDBHFzdHJsAzM2BHF1ZXJ5A1lvdVR1YmUgZmxhbWUgaW4gY2hsb3JpbmUgYXRtb3NwaGVyZQR0X3N0bXADMTQyNzEyMzkyMg--?p=YouTube+flame+in+chlorine+atmosphere&fr2=sb-top-search&fr=yfp-t-252&fp=1
Of course, it’s not clear to me that there are worlds with chlorine atmospheres. But if an oxygen atmosphere, produced by organisms that emit oxygen as a waste produc t, is possible, I se no reason why a world with a chlorine atmospherre might not be similarly possible.
I am pretty sure that meteors shooting into planets with atmospheres of halogen (chlorine, fluorine, etc) or with ammonia or boron compounds will have spectacular flames from the metal in the meteor reacting with the atmosphere.
I’m not about to try the math, but I suspect the energy output of any chemical combustion in that scenario would be wildly outclassed – completely swamped – by the simple kinetic energy conversion of a fast-moving rock plowing into (relatively) stationary atmosphere. Kinetic energy release sufficient to convert part of the impactor to gas, and the affected atmospheric gas to plasma.
I would request you to do the math. Not all atmospheres are as dense as earths. I am pretty sure there will be at least one atmosphere to just dense enough and having the right composition for a meteor (rather meteorite) to burn into a nice flame before hitting ground.
See post #12.
As pointed out a few years ago by chorpler in this thread, SF author Larry Niven once theorized that Pluto had layers of frozen gases. Freeze distilled, so that various distinct gases deposited on the surface of the planet at different strata. In his novel World of Ptavvs, a spaceship using its drive system to rapidly drill down through the layers of gas snow and ice (to get to the Maguffin buried deep below) liberates a great deal of oxygen gas in an environment full of recently-liberated hydrogen and hydrocarbon gases and lights the planet on fire:
I’m pretty sure the idea of strata of distinct gases, or any readily available oxidizer in general, is pretty well discredited. But it’s a cool idea and a very imaginative description in a very good book.
Since this is your idea, perhaps you should do the maths yourself. Iron burns in oxygen, but the luminosity of a typical iron-rich meteor comes mostly from the kinetic energy rather than the oxidisation of iron. Burning a pea-sized pellet of iron in oxygen would only produce a fraction of the light which comes from a pea-sized iron-rich meteor hitting the atmosphere at 30km/s or more.
Sorry – missed that in my quick scan.
Somebody call?