Fate of the outer planets as the Sun enters red giant phase

On a number of documentaries (such as NG's "Naked Science" series) and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward as
the Sun sheds mass and weakens its gravity well (I believe it swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

wrote in message
...
On a number of documentaries (such as NG's "Naked Science" series) and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward as
the Sun sheds mass and weakens its gravity well (I believe it swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

Interesting questions.

The expansion itself will not have any effect on solar gravity. But mass
loss, as you rightly say, will have this effect. I'm not sure exactly how
much the Sun's luminosity will increase at this stage but at times I think
it will reach about 1000 times current luminosity (I could look it up but
I'm in a hurry). Even with larger orbits, Jupiter and Saturn will get
pretty warm, warmer than Earth now. Ice moons may vaporize. Though there
will be an increase in atmospheric loss, I doubt the giant planets will lose
all their atmospheres.

One claim that I think is justified, is that conditions on Titan will
become, briefly (cosmically speaking), ideal for development of life in
terms of temperature and chemistry.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

wrote:
On a number of documentaries (such as NG's "Naked Science" series) and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward as
the Sun sheds mass and weakens its gravity well (I believe it swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

Use the original 7x solar mass of Sirius B as an example.

~ BG

On Oct 6, 12:36 am, "Mike Dworetsky"
wrote:
wrote in message

...

On a number of documentaries (such as NG's "Naked Science" series) and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward as
the Sun sheds mass and weakens its gravity well (I believe it swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

Interesting questions.

The expansion itself will not have any effect on solar gravity. But mass
loss, as you rightly say, will have this effect. I'm not sure exactly how
much the Sun's luminosity will increase at this stage but at times I think
it will reach about 1000 times current luminosity (I could look it up but
I'm in a hurry). Even with larger orbits, Jupiter and Saturn will get
pretty warm, warmer than Earth now. Ice moons may vaporize. Though there
will be an increase in atmospheric loss, I doubt the giant planets will lose
all their atmospheres.

One claim that I think is justified, is that conditions on Titan will
become, briefly (cosmically speaking), ideal for development of life in
terms of temperature and chemistry.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

The 7x1x solar mass flashover of Sirius B becoming a white dwarf
seems good enough. Why don't you supercomputer simulate it for us?

~ BG

"BradGuth" wrote in message
...
On Oct 6, 12:36 am, "Mike Dworetsky"
wrote:
wrote in message

...

On a number of documentaries (such as NG's "Naked Science" series) and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward as
the Sun sheds mass and weakens its gravity well (I believe it swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

Interesting questions.

The expansion itself will not have any effect on solar gravity. But mass
loss, as you rightly say, will have this effect. I'm not sure exactly
how
much the Sun's luminosity will increase at this stage but at times I
think
it will reach about 1000 times current luminosity (I could look it up but
I'm in a hurry). Even with larger orbits, Jupiter and Saturn will get
pretty warm, warmer than Earth now. Ice moons may vaporize. Though
there
will be an increase in atmospheric loss, I doubt the giant planets will
lose
all their atmospheres.

One claim that I think is justified, is that conditions on Titan will
become, briefly (cosmically speaking), ideal for development of life in
terms of temperature and chemistry.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

The 7x1x solar mass flashover of Sirius B becoming a white dwarf
seems good enough. Why don't you supercomputer simulate it for us?

~ BG

Why bother? It's been done for a 1-solar mass star of solar composition...

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On Oct 7, 11:36 pm, "Mike Dworetsky"
wrote:
"BradGuth" wrote in message

...



On Oct 6, 12:36 am, "Mike Dworetsky"
wrote:
wrote in message

...

On a number of documentaries (such as NG's "Naked Science" series) and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward as
the Sun sheds mass and weakens its gravity well (I believe it swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

Interesting questions.

The expansion itself will not have any effect on solar gravity. But mass
loss, as you rightly say, will have this effect. I'm not sure exactly
how
much the Sun's luminosity will increase at this stage but at times I
think
it will reach about 1000 times current luminosity (I could look it up but
I'm in a hurry). Even with larger orbits, Jupiter and Saturn will get
pretty warm, warmer than Earth now. Ice moons may vaporize. Though
there
will be an increase in atmospheric loss, I doubt the giant planets will
lose
all their atmospheres.

One claim that I think is justified, is that conditions on Titan will
become, briefly (cosmically speaking), ideal for development of life in
terms of temperature and chemistry.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

The 7x1x solar mass flashover of Sirius B becoming a white dwarf
seems good enough. Why don't you supercomputer simulate it for us?

~ BG

Why bother? It's been done for a 1-solar mass star of solar composition...

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

What a pathetic cop out.

Why don't you want to know of how and perhaps when some of our planets
and moons came to past?

What's the matter this time?

Isn't a seriously nearby 7x solar mass star that's flashing itself
down to a 1x solar mass white dwarf, good enough?

~ BG

"BradGuth" wrote in message
...
On Oct 7, 11:36 pm, "Mike Dworetsky"
wrote:
"BradGuth" wrote in message

...



On Oct 6, 12:36 am, "Mike Dworetsky"
wrote:
wrote in message

...

On a number of documentaries (such as NG's "Naked Science" series)
and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like
to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward
as
the Sun sheds mass and weakens its gravity well (I believe it
swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

Interesting questions.

The expansion itself will not have any effect on solar gravity. But
mass
loss, as you rightly say, will have this effect. I'm not sure exactly
how
much the Sun's luminosity will increase at this stage but at times I
think
it will reach about 1000 times current luminosity (I could look it up
but
I'm in a hurry). Even with larger orbits, Jupiter and Saturn will get
pretty warm, warmer than Earth now. Ice moons may vaporize. Though
there
will be an increase in atmospheric loss, I doubt the giant planets
will
lose
all their atmospheres.

One claim that I think is justified, is that conditions on Titan will
become, briefly (cosmically speaking), ideal for development of life
in
terms of temperature and chemistry.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

The 7x1x solar mass flashover of Sirius B becoming a white dwarf
seems good enough. Why don't you supercomputer simulate it for us?

~ BG

Why bother? It's been done for a 1-solar mass star of solar
composition...

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

What a pathetic cop out.


Idiot. Troll. Why should I have to do "supercomputer simulations" just to
make you "happy"?

Why don't you want to know of how and perhaps when some of our planets
and moons came to past?


They were created in a binary system with two stars far more massive that
the Sun? Who'd a thunk it? Why would I want to answer that question when
the OP asked a perfectly reasonable one that I did answer? Just to please a
troll?

The question was about how giant planets might end up, not how they
originated. Reading comprehension is not your strong point.

What's the matter this time?

Well, you are a famous net-loon, for one thing. But I digress.


Isn't a seriously nearby 7x solar mass star that's flashing itself
down to a 1x solar mass white dwarf, good enough?

That's fine. Why don't YOU run the simulation on a supercomputer, then
report back to us after you have submitted the paper to a peer-reviewed
journal and had it accepted?

But your attempt to steer the thread onto another question is not relevant
to the OP question. See

I-J Sackmann, A I Boothroyd, and K E Kraemer, Astrophysical Journal vol 418,
p. 457, 1993. Essentially what they predict is that the Sun will lose mass
via an increase in the solar wind as it evolves into a red giant. Enough
mass will be lost eventually to reduce the Sun to about 0.54 of its present
mass. Although the Sun's radius will reach 0.99 AU (Earth's present orbital
mean distance is by definition 1.00 AU), it will have lost so much mass
that, in accord with Newtonian gravitation and Kepler's laws, Venus will
have moved outwards to 1.22 AU and Earth itself to 1.69 AU. Thus neither
planet will experience engulfment, although both will get pretty
hot--probably enough to melt the surface rocks, possibly enough to vaporize
the planets. (There are still some uncertainties in the data used in their
calculations.)

All of this lies about 7.5 billion years in the future.

Some of these calculations may have been slightly modified by later work.

I understand there is a Sky & Telescope article on this subject:

Laughlin,G.P., From Here to Eternity: The Fate of the Sun and the Earth, v.
112, p 32, June 2007 but I haven't got it available here.


--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

But your attempt to steer the thread onto another question is not relevant
to the OP question. *See

I-J Sackmann, A I Boothroyd, and K E Kraemer, Astrophysical Journal vol 418,
p. 457, 1993. *Essentially what they predict is that the Sun will lose mass
via an increase in the solar wind as it evolves into a red giant. Enough
mass will be lost eventually to reduce the Sun to about 0.54 of its present
mass. Although the Sun's radius will reach 0.99 AU (Earth's present orbital
mean distance is by definition 1.00 AU), it will have lost so much mass
that, in accord with Newtonian gravitation and Kepler's laws, Venus will
have moved outwards to 1.22 AU and Earth itself to 1.69 AU. Thus neither
planet will experience engulfment, although both will get pretty
hot--probably enough to melt the surface rocks, possibly enough to vaporize
the planets. (There are still some uncertainties in the data used in their
calculations.)

All of this lies about 7.5 billion years in the future.

Some of these calculations may have been slightly modified by later work.

I understand there is a Sky & Telescope article on this subject:

Laughlin,G.P., *From Here to Eternity: The Fate of the Sun and the Earth, v.
112, p 32, June 2007 but I haven't got it available here.


That's quite interesting but my question pertains to the fate of the
outer planets-Jupiter, Saturn, Uranus and Neptune.

Basically will they stay intact or will (especially for Jupiter as
it's the closest to the sun) as the Sun's luminosity increases and its
mass loss due dramatically increased solar wind and coronal mass
ejections. Strip most if not all their atmospheres off essentially
leaving their rocky cores behind. Would Jupiter's core be big enough
to retain an atmosphere consisting of the remaining heavier gases
(such as nitrogen, carbon dioxide, methane, ammonia and inert gases),
with the hydrogen and helium preferentially stripped from their
atmospheres. Although as a fraction the gases(excluding hydrogen and
helium) in Jupiter's atmosphere for instance only make a tiny
proportion of it, but in absolute terms must be greater than Earth's
atmospheric mass.

Scrumpy.

e

wrote in message
...

But your attempt to steer the thread onto another question is not relevant
to the OP question. See

I-J Sackmann, A I Boothroyd, and K E Kraemer, Astrophysical Journal vol
418,
p. 457, 1993. Essentially what they predict is that the Sun will lose mass
via an increase in the solar wind as it evolves into a red giant. Enough
mass will be lost eventually to reduce the Sun to about 0.54 of its
present
mass. Although the Sun's radius will reach 0.99 AU (Earth's present
orbital
mean distance is by definition 1.00 AU), it will have lost so much mass
that, in accord with Newtonian gravitation and Kepler's laws, Venus will
have moved outwards to 1.22 AU and Earth itself to 1.69 AU. Thus neither
planet will experience engulfment, although both will get pretty
hot--probably enough to melt the surface rocks, possibly enough to
vaporize
the planets. (There are still some uncertainties in the data used in their
calculations.)

All of this lies about 7.5 billion years in the future.

Some of these calculations may have been slightly modified by later work.

I understand there is a Sky & Telescope article on this subject:

Laughlin,G.P., From Here to Eternity: The Fate of the Sun and the Earth,
v.
112, p 32, June 2007 but I haven't got it available here.


That's quite interesting but my question pertains to the fate of the
outer planets-Jupiter, Saturn, Uranus and Neptune.

Basically will they stay intact or will (especially for Jupiter as
it's the closest to the sun) as the Sun's luminosity increases and its
mass loss due dramatically increased solar wind and coronal mass
ejections. Strip most if not all their atmospheres off essentially
leaving their rocky cores behind. Would Jupiter's core be big enough
to retain an atmosphere consisting of the remaining heavier gases
(such as nitrogen, carbon dioxide, methane, ammonia and inert gases),
with the hydrogen and helium preferentially stripped from their
atmospheres. Although as a fraction the gases(excluding hydrogen and
helium) in Jupiter's atmosphere for instance only make a tiny
proportion of it, but in absolute terms must be greater than Earth's
atmospheric mass.

Scrumpy.

e
-------------------------------------------------------------------------------------

Let Lsun and Msun be current luminosity and mass.

To answer your question as best I can, the paper listed says that eventually
the Sun ascends the Red Giant Branch to a luminosity of 2300 Lsun and later
on a peak of 5200 Lsun on the Asymptotic Giant Branch. By then its mass is
down to 0.54 Msun, so Jupiter and Saturn would have migrated further out.

Mumble mumble inverse square law mumble. Consider Saturn, currently at
around 10AU, receiving 1% of the amount of solar heating as Earth. Mass
loss of the Sun moves it out to around 17AU, where it receives 0.3% of the
amount of heating as Earth today. Then multiply luminosity by say 2,000 (a
sort of average) so Saturn would get around 6-7 times the heating that Earth
currently gets. Roughly this makes the temperature expected around that of
the average on Mercury or a bit more. I'm estimating here, so the numbers
could be off a bit but not by a huge amount.

Jupiter would of course be much hotter, maybe double Saturn (in Kelvin), but
I think these figures suggest temperatures lower than those of giant
exoplanets in close orbit around their stars, and these still retain their
atmospheres (mainly because of their large masses and high escape
velocities). Also, the duration of high luminosity is relatively short.
Uranus and Neptune may get warm enough to experience some atmosphere loss,
as their escape velocities are lower, but then again they might be so far
out that their temperatures would be comparable to Earth's today.

So I think the giant planets would retain their atmospheres through the
solar red giant phases.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On Oct 8, 10:10 am, "Mike Dworetsky"
wrote:
"BradGuth" wrote in message

...



On Oct 7, 11:36 pm, "Mike Dworetsky"
wrote:
"BradGuth" wrote in message

...

On Oct 6, 12:36 am, "Mike Dworetsky"
wrote:
wrote in message

...

On a number of documentaries (such as NG's "Naked Science" series)
and
in text books it discusses in some detail the fate of the inner
planets (Mercury, Venus, Earth and Mars) as the Sun enters the final
stages of its existence and swells into a red giant. What i'd like
to
know is what will happen to the outer planets (Jupiter, Saturn,
Uranus, Neptune and Pluto), I know they'll start to migrate outward
as
the Sun sheds mass and weakens its gravity well (I believe it
swelling
up to a red giant will have some effect as this will effect the
distribution of its remaining mass). Will the massive increase in
solar luminosity and solar wind start stripping off the gas giants
atmospheres (which should be exponential as the further mass is lost
the weaker their gravity and hence the grip on the gaseous envelopes
plus the effects of increased surface to area ratio allowing any
remaining heat of formation to escape and further swell their
atmospheres).

Interesting questions.

The expansion itself will not have any effect on solar gravity. But
mass
loss, as you rightly say, will have this effect. I'm not sure exactly
how
much the Sun's luminosity will increase at this stage but at times I
think
it will reach about 1000 times current luminosity (I could look it up
but
I'm in a hurry). Even with larger orbits, Jupiter and Saturn will get
pretty warm, warmer than Earth now. Ice moons may vaporize. Though
there
will be an increase in atmospheric loss, I doubt the giant planets
will
lose
all their atmospheres.

One claim that I think is justified, is that conditions on Titan will
become, briefly (cosmically speaking), ideal for development of life
in
terms of temperature and chemistry.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

The 7x1x solar mass flashover of Sirius B becoming a white dwarf
seems good enough. Why don't you supercomputer simulate it for us?

~ BG

Why bother? It's been done for a 1-solar mass star of solar
composition...

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

What a pathetic cop out.

Idiot. Troll. Why should I have to do "supercomputer simulations" just to
make you "happy"?

My goodness, Sirius B as having recently gone from a 7x solar mass
down to a 1x and having lost its planets is really ****ing you off.
Why is that?


Why don't you want to know of how and perhaps when some of our planets
and moons came to past?

They were created in a binary system with two stars far more massive that
the Sun? Who'd a thunk it? Why would I want to answer that question when
the OP asked a perfectly reasonable one that I did answer? Just to please a
troll?

The question was about how giant planets might end up, not how they
originated. Reading comprehension is not your strong point.

And where exactly do you think some of those Sirius B planets went?


What's the matter this time?

Well, you are a famous net-loon, for one thing. But I digress.

Digress all you like, but meanwhile those once upon a time planets of
Sirius B went somewhere, and lo and behold the nearest other somewhere
was our passive solar system.

Why do you think our interstellar association with Sirius is not in
any way connected with ice ages or global warming (ice age thawing)
cycles?


Isn't a seriously nearby 7x solar mass star that's flashing itself
down to a 1x solar mass white dwarf, good enough?

That's fine. Why don't YOU run the simulation on a supercomputer, then
report back to us after you have submitted the paper to a peer-reviewed
journal and had it accepted?

I'd love to do just that. Of course it's obvious that you'd never
care to help others, not even Einstein.


But your attempt to steer the thread onto another question is not relevant
to the OP question. See

I-J Sackmann, A I Boothroyd, and K E Kraemer, Astrophysical Journal vol 418,
p. 457, 1993. Essentially what they predict is that the Sun will lose mass
via an increase in the solar wind as it evolves into a red giant. Enough
mass will be lost eventually to reduce the Sun to about 0.54 of its present
mass. Although the Sun's radius will reach 0.99 AU (Earth's present orbital
mean distance is by definition 1.00 AU), it will have lost so much mass
that, in accord with Newtonian gravitation and Kepler's laws, Venus will
have moved outwards to 1.22 AU and Earth itself to 1.69 AU. Thus neither
planet will experience engulfment, although both will get pretty
hot--probably enough to melt the surface rocks, possibly enough to vaporize
the planets. (There are still some uncertainties in the data used in their
calculations.)

All of this lies about 7.5 billion years in the future.

Some of these calculations may have been slightly modified by later work.

I understand there is a Sky & Telescope article on this subject:

Laughlin,G.P., From Here to Eternity: The Fate of the Sun and the Earth, v.
112, p 32, June 2007 but I haven't got it available here.

--
Mike Dworetsky

I happen to agree that Earth at 1.7 AU will not have come to its final
demise simply because our sun eventually goes into its red giant
phase.

Then why not use Sirius B as a perfectly good and nearby example of
what happens when a big star with any number of planets goes red
giant, and then rather quickly flashes itself over into a little white
dwarf.

Seems to me that any 7x that's going down to 1x tidal radius is going
to have problems holding onto whatever planets that had been gradually
allowed to orbit further away, especially when it quickly flashes over
from the red giant into that little 1x white dwarf.

~ BG