Why doesn't jupiter explode?

[Layers]

Jupiter is made of hydrogen and helium or so I learned. These are the same gases present in the sun. Why doesn't jupiter explode or give birth to starts as nebulae do.

Jupiter has even been supplied ignition several times when comets hit it and explode. Why doesn't the entire planet explode then. 

Another question, in absolute zero temperature and vacuum conditions, given enough time, can any gases or other organic material produce itself. 

[chenbeier]

On Jupiter there is not the same condition like on the sun. Hydrogen needs a very high temperature and pressure to do fusion reaction. A comet also don't have that energy.

Regarding the produce of organic material it need the condition like on our planet. And some spirit of god.

[Ghideon]

Here are some short answers:

31 minutes ago, Layers said:

give birth to starts as nebulae do

Jupiter does not have enough mass to generate high enough pressure and temperature to start a fusion reaction. The lowest mass stars has about 80 times the mass of Jupiter if i remember correctly. 

28 minutes ago, Layers said:

Jupiter has even been supplied ignition several times when comets hit it and explode. Why doesn't the entire planet explode then. 

An explosion requires a mixture of matter to ignite; hydrogen and oxygen for instance. A quick check at https://en.wikipedia.org/wiki/Atmosphere_of_Jupiter tells that there is not much oxygen available. 

1 minute ago, chenbeier said:

And some spirit of god.

I would not take that as a scientific fact without some proper references.

[Janus]

37 minutes ago, Layers said:

Jupiter is made of hydrogen and helium or so I learned. These are the same gases present in the sun. Why doesn't jupiter explode or give birth to starts as nebulae do.

Jupiter has even been supplied ignition several times when comets hit it and explode. Why doesn't the entire planet explode then. 

Another question, in absolute zero temperature and vacuum conditions, given enough time, can any gases or other organic material produce itself. 

Hydrogen fusion, the process by which the Sun generates requires special conditions, as pointed out by chenbeier.( which is why we are having such a hard time developing fusion power plants.   Even our hydrogen bombs need a fission bomb as a trigger). It is estimated that you would need something between 70 and 80 times the mass of Jupiter to maintain fusion at the core. 

Comets hit the outer atmosphere of the planet where the gases are even more rarefied.  While these comets could provide the energy needed to ignite chemical combustion, Jupiter's atmosphere isn't combustible. For that you need something the burn (in this case the hydrogen), and something for it to chemically react with (like oxygen).   Jupiter's atmosphere has plenty of the first,  but is too deficient in the second to support such combustion.

[Moontanman]

4 hours ago, chenbeier said:

On Jupiter there is not the same condition like on the sun. Hydrogen needs a very high temperature and pressure to do fusion reaction. A comet also don't have that energy.

Regarding the produce of organic material it need the condition like on our planet. And some spirit of god.

"Spirit of God" care to elaborate?