Is Jupiter a failed Sun?

[FLO]

They say there is no such thing as a stupid question ... so here goes:

Someone has told me that Jupiter is essentially a failed Sun?  That it has all the ingredients to be a Sun but that for one reason or another, it never ignited? 

Is there any truth in this?

Thanks,

Steve

[OXO]

From what i can remember if Jupiter had been larger then it would of been a star because the amount of pressure would inc nuclear fusion on a large scale due too the gravity at it's central core. If this would of happened life would not of been possiable on earth.

James

[Astroman]

Jupiter is much, much to small to becoma a star.  It would have to be at least 80 times larger to create enough internal pressure to ignite.

It is, however, just about the size of the core of the Sun that is fusing hydrogen to helium.

[FLO]

Thanks James & Astroman,

Is it only its small size that prevents it becoming a Sun?  I mean, are all the necessary ingredients present? 

I know it is all relative but it is odd to hear Jupiter described as small when it is twice as massive as all the other planets combined (the mass of Jupiter is 318 times that of Earth). 

http://tinyurl.com/dlx8k

Steve

[Jamie]

Right thats it NO MORE SMOKING NEAR JUPITER just in case.

Very interesting theory though.

[FLO]

Found another interesting - at least to me - Jupiter fact:

Jupiter has no solid surface. Under it's atmosphere is a large liquid ocean of hydrogen and water. What lies in between that ocean and the atmosphere? Actually there is no in between. The atmosphere slowly gets thicker and thicker until it becomes part of the ocean. In other words Jupiter's ocean has no surface on which you could float a boat. The sky slowly becomes the ocean.

[Astroman]

The composition of Jupiter, if increaded to the mass of the Sun, could promote fusion, but the presence of methane and other "contaminants" would make it tricky to sustain. So size is not the only factor. Density is another factor, but more mass of similar content would certainly help that.

Skyguy: I'll try to keep your smoking coment in mind, next time I venture close enough.

Steve: Current theory allows for a somewnat solid surface-of Hydrogen! At the pressures calculated for the core of Jupiter, it is possible that hydrogen can be compressed enough to form a solid. Temperatures are a problem though. Nothing man-made, and certainly man himself, would never survive for long, or even the journey to find out. When they crashed Galileo into the atmosphere, it lasted for 45 minutes or so, but it only penetrated about 10% of the way in-not even close to the "surface". It's problematic if the solid could endure at the temperature of the core.