How much bigger would Jupiter have to become to start burning ? Is there
anything in space that could impact it to get it started? Or is
mass/gravity the only thing?

CNC Area wrote:

How much bigger would Jupiter have to become to start burning ?
Is there anything in space that could impact it to get it started?
Or is mass/gravity the only thing?


About 13 jupiter masses to start
About 50 jupiter masses to sustain

CNC Area wrote:

How much bigger would Jupiter have to become to start burning ? Is there
anything in space that could impact it to get it started? Or is
mass/gravity the only thing?

A common figure given is that Jupiter is ~ 1/75th the mass needed to
ignite hydrogen fusion.

http://www.solstation.com/stars/jupiter.htm
http://www.mira.org/fts0/planets/099/text/txt001x.htm

Other estimates put the figure @ ~ 1/50th.

"Minimum Mass for Stars"
http://www.mira.org/fts0/planets/099/text/txt001x.htm

Sam Wormley wrote in message ...
CNC Area wrote:

How much bigger would Jupiter have to become to start burning ?
Is there anything in space that could impact it to get it started?
Or is mass/gravity the only thing?


About 13 jupiter masses to start
About 50 jupiter masses to sustain

Too bad. I like the idea of something striking it to light it off
like a match head.

CNC Area wrote:

How much bigger would Jupiter have to become to start burning ? Is
there anything in space that could impact it to get it started? Or
is mass/gravity the only thing?

At least 10X bigger for deuterium fusion (brown dwarf), way bigger for
hydrogen fusion. Look up the required mases in Google or aXiv.org
search. Fusion is elicited by pressure (higher), temperature
(higher), and containment time (higher). There is no aspect of
imaginable technology that would alter hydrostatic equilibrium on a
planetary scale.

Droppng an H-bomb deep into Jupiter's atmosphere would only
disassemble it - the exact opposite of what you want.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!

In sci.physics, Edward Green

wrote
on 22 May 2004 05:49:54 -0700
:
Sam Wormley wrote in message ...
CNC Area wrote:

How much bigger would Jupiter have to become to start burning ?
Is there anything in space that could impact it to get it started?
Or is mass/gravity the only thing?


About 13 jupiter masses to start
About 50 jupiter masses to sustain

Too bad. I like the idea of something striking it to light it off
like a match head.

Or one can go with Arthur C. Clarke's idea -- not sure if it was
in _2010_ or _2061_ -- with the ebon block multiplying and
shrinking down Jupiter until it ignites.

Not sure if that would work horribly well, either, unless the
ebon blocks can somehow create enough pressure in a fixed volume.

(Besides, we've already seen something striking it. And it was
pretty darned striking, even if we missed the actual explosion
since it was on the night side of the planet. :-) )

--
#191, -- insert random monolith here
It's still legal to go .sigless.

Uncle Al wrote in message ...
CNC Area wrote:

How much bigger would Jupiter have to become to start burning ? Is
there anything in space that could impact it to get it started? Or
is mass/gravity the only thing?

At least 10X bigger for deuterium fusion (brown dwarf), way bigger for
hydrogen fusion. Look up the required mases in Google or aXiv.org
search. Fusion is elicited by pressure (higher), temperature
(higher), and containment time (higher). There is no aspect of
imaginable technology that would alter hydrostatic equilibrium on a
planetary scale.

Droppng an H-bomb deep into Jupiter's atmosphere would only
disassemble it - the exact opposite of what you want.

Ah ... don't ask me to back up this claim with numbers; but given the
size of the planet, I don't think we could build a bomb big enough to
significantly perturb the atmosphere. Isn't the Great Red Spot (1) a
storm (2) about the size of the Earth?