Why isn't Uranus a Bomb?

First let me just state for the record that I'm not the sharpest pencil when it comes to Chemistry...

It's said that the planet, Uranus is primarily composed of gas and various ices. The atmosphere is about 85% hydrogen, 15% helium and traces of methane, while the interior is richer in heavier elements, most likely compounds of oxygen, carbon, and nitrogen, as well as rocky materials.

Now, basic chemistry teaches us that Hydrogen is a highly flammable diatomic gas. We can go further by reminding ourselves that Hydrogen plays a role in nuclear fusion in stars...

Helium, is not that flammable, but Methane is extremely flammable...

So, all that in mind, why is it that the planet Uranus have not exploded yet? If hydrogen and methane exist in Uranus' atmosphere in their pure form, then Uranus is one flammable place! (The question is of course if Hydrogen exists in its pure form in the atmosphere?)

Should a 2-meter iron meteorite (meteoroid) enter the planet's atmosphere at speeds of 15 km/s (this is earth's terminal velocity, but Uranus' will probably be higher??) we're talking extremely high temperatures! Why doesn't this spark a global explosion, which will probably destroy the planet, Uranus?

Here's your answer:

85% hydrogen, 15% helium and traces of methane

There is no oxidizer. It doesn't have the oxygen in the atmosphere needed to cause the "match to strike". You've got to have an ignition source, otherwise hydrogen just hangs around like anything else.

...actually...a long time ago I thought about the same thing with Jupiter...

But then I got the "no oxygen" answer. Oh well. It would be interesting if you could just drop a match into Jupiter or Uranus and blow it up...

Originally posted by Valhall
There is no oxidizer. It doesn't have the oxygen in the atmosphere needed to cause the "match to strike". You've got to have an ignition source, otherwise hydrogen just hangs around like anything else.

Ah, thanks Val! I understand the "triangle" necessary to create fire. But does the same rule apply everywhere in the Universe?

Can we use the Sun as an example? It's composed of 74% Hydrogen, and 25% Helium (as a result of the nuclear fusion). It doesn't have an oxidizer. What "sparked" the Sun to "explode" in the first place? (Excuse my use of such "loose" terms )

And it's guessed that there are oxygen compounds on Uranus...?

Originally posted by Gemwolf

Originally posted by Valhall
There is no oxidizer. It doesn't have the oxygen in the atmosphere needed to cause the "match to strike". You've got to have an ignition source, otherwise hydrogen just hangs around like anything else.

Ah, thanks Val! I understand the "triangle" necessary to create fire. But does the same rule apply everywhere in the Universe?

Can we use the Sun as an example? It's composed of 74% Hydrogen, and 25% Helium (as a result of the nuclear fusion). It doesn't have an oxidizer. What "sparked" the Sun to "explode" in the first place? (Excuse my use of such "loose" terms

)

And it's guessed that there are oxygen compounds on Uranus...?

CKK is going to be your 'spert on these questions. It would seem to me that the intense heat due to awesome pressure created by the mass of the Sun, in combination with what oxidizers were present at the time, would have been sufficient to ignite the hydrogen in the Sun, whereas Uranus doesn't have this. What is more curious to me is why Jupiter didn't go solar. I mean the interior of Jupiter is supposed to be under such extreme pressure that the hydrogen at its interior is METALLIC. It seems the big question is under the intense pressures and internal heat of Jupiter - why the heck hasn't it exploded?

I'm no space guru - just a solar system junky - so hopefully CKK will see this and enlighten us (pardon the pun).

Gemwolf:

The answer to how a sun does it is pressure, pressure with massive astral bodies like the sun, caused by gravity.

An nuclear weapon can work in either of the following basic configurations:


1: radioactive material encased in ultra highvelocity high explosives. When the explosives are detonated, the presure on the radioactive material becomes so high that it kicks of a nuclear reaction.

2: radioactive material encased in high presure resistant material, in this, a bullet will be fired at high speed, giving the needed presure to start a nuclear reaction.

The reason why planets like Jupiter don't burst into flames is both because of extreme presure and because that very presure still isn't high enough to start a nuclear reaction.

Oxygen is actualy present on those planets, but due to the presures and temperatures involved and concentrations compared to the hydrogen, methane and other combustable gasses, its insufficient to start an oxydation process.

The only way you can light blowtorches, gasoline and all other known combustables is when:

A: the needed oxydizer is present.
B: the correct fuel mixture is achieved.
C: the presure and temperature are nominal.

Originally posted by Valhall
I mean the interior of Jupiter is supposed to be under such extreme pressure that the hydrogen at its interior is METALLIC. It seems the big question is under the intense pressures and internal heat of Jupiter - why the heck hasn't it exploded?

I'm no space guru - just a solar system junky - so hopefully CKK will see this and enlighten us (pardon the pun).

Jupiter does not have the mass to sustain nuclear fusion as I understand it.

Well, it's got to be something like that. lol It's missing something! But I think it's right there on the border isn't it? Jupiter and Saturn are my favorite planets in the solar system. I think Uranus comes in third. They do the whole planet thing with style.

Yeah the sun doesn't need oxygen to burn since it's a nuclear rather than chemical reaction that creates its heat.

Originally posted by thematrix
Gemwolf:

The answer to how a sun does it is pressure, pressure with massive astral bodies like the sun, caused by gravity.

Thanks for the explanation, Matrix... It clears up most of the questions.
While you're on a role... ( ) What pressure would be necessary for one of the "gas planets" to start a nuclear reaction, and is there a natural occurrence that could cause the "pressurization" of one of the planets (such as a supernovae). Would it be safe to guess that the sun was at one stage a planet, and by a certain chain of events changed into a star or does all stars start out as clouds? Or in other words is it possible for any planet to turn into a star?

It's completely up to the mass of the body, the pressure is created by its gravity. It's thought the minimum mass needed to initiate long-term fusion and become a main sequence star is thought to be around 80 times the size of Jupiter.

If by some freak occurance Jupiters mass would increase 100 fold, it should have enough mass and with that presure, to start a nuclear reaction. But as that shows, a gas giant like Jupiter has 80x to 100x to little mass to get to that point.

A supernova is more likely to blow gas away from jupiter, burning it up in the wake of the supernova explosion.

If by some freak occurance this doesn't happen and matter from the sun gets picked up by Jupiters and increases its mass 80-100 fold, and Jupiter stays nicely in place, it would become a star.

Quite a few unlikely IFS to have it actualy happen.

Primordal stars are thought to come into existence because of the clustering together and compacting of matter in a gas cloud, as its mass increases, more of this gas and matter is pulled into the new body and at some point, when the mass is sufficient, a nuclear reaction will start.

Mass, pressure and gravity are all directly related and without an artificial means to create pressure(like in a nuke), gravity(to get the needed presure naturaly), or mass(to get the needed natural gravity to get to the needed natural presure), you would need something 80x-100x higher in mass then Jupiter to start a new star.

(ps, anyone notice the pun in the title of this thread? UrAnus jokes never get old I guess XD)

[edit on 15/8/06 by thematrix]

Originally posted by thematrix
Quite a few unlikely IFS to have it actualy happen.

Again thank you, Matrix. That's all the questions I can come up with at the moment... (I'll think up some more when I can't sleep tonight!)

May I offer you this gift for your effort:

You have voted thematrix for the Way Above Top Secret award. You have one more vote left for this month.

And a special thanks to Val and djohnsto77 for their input as well! Who needs Wikipedia when we have sources like you guys?

I'd just like to add any free oxygen available I'm sure combined quickly with other nearby chemicals such hydrogen as the planet slowly formed, so all the chemical reactions were most likely a whimper rather than a bang. The result would be water, and there are ice clouds detected in these planets...


[edit on 8/15/2006 by djohnsto77]

Originally posted by Valhall
Here's your answer:

85% hydrogen, 15% helium and traces of methane

There is no oxidizer. It doesn't have the oxygen in the atmosphere needed to cause the "match to strike". You've got to have an ignition source, otherwise hydrogen just hangs around like anything else.

I can just image if there was oxygen, Some astronaut walks out for a sapce smoke, lights it and throws the match at Uranus and then kaboom there goes the planet

Originally posted by Gemwolf
First let me just state for the record that I'm not the sharpest pencil when it comes to Chemistry...

It's said that the planet, Uranus is primarily composed of gas and various ices. The atmosphere is about 85% hydrogen, 15% helium and traces of methane, while the interior is richer in heavier elements, most likely compounds of oxygen, carbon, and nitrogen, as well as rocky materials.

Now, basic chemistry teaches us that Hydrogen is a highly flammable diatomic gas. We can go further by reminding ourselves that Hydrogen plays a role in nuclear fusion in stars...

Helium, is not that flammable, but Methane is extremely flammable...

So, all that in mind, why is it that the planet Uranus have not exploded yet? If hydrogen and methane exist in Uranus' atmosphere in their pure form, then Uranus is one flammable place! (The question is of course if Hydrogen exists in its pure form in the atmosphere?)

Should a 2-meter iron meteorite (meteoroid) enter the planet's atmosphere at speeds of 15 km/s (this is earth's terminal velocity, but Uranus' will probably be higher??) we're talking extremely high temperatures! Why doesn't this spark a global explosion, which will probably destroy the planet, Uranus?

One may assume the environment is predictable, as on this planet.
Then, knowing free-form elements tend to stabilize dynamically, cohessively; you know that there are compounds.

Now, if certain debris where to enter, say +CO^3 (free-form Carbon), look out.

I don't know about uranus, but mine is a bomb or sorts

Originally posted by porky1981
I don't know about uranus, but mine is a bomb or sorts

Every anus can have explosive properties due to methane emissions, but that would be a blue angel.
The best a planet like Jupiter could hope to achieve would be a brown dwarf status if it aquired enough mass.


EDIT: Just to curtail the jokes, the guy on the right only has a good tan.
He is not a brown dwarf................




[edit on 19/8/2006 by anxietydisorder]

I just had too, sorry... lol

With enough oxygen, you can make anything burn.

It's a fun thing to do, if you have access to a tank of oxygen.