Lunar water brings portions of Moon's origin story into question

"Washington, D.C.—The Moon has much more water than previously thought,
a team of scientists led by Carnegie's Erik Hauri has discovered. Their
research, published May 26 in Science Express, shows that inclusions of
magma trapped within crystals collected during the Apollo 17 mission
contain 100 times more water than earlier measurements. These results
could markedly change the prevailing theory about the Moon's origin.

The research team used a state-of-the-art NanoSIMS 50L ion microprobe to
measure seven tiny samples of magma trapped within lunar crystals as
so-called "melt inclusions." These samples came from volcanic glass
beads—orange in appearance because of their high titanium content—which
contained crystal-hosted melt inclusions. These inclusions were
prevented from losing the water within when explosive volcanic eruptions
brought them from depth and deposited them on the Moon's surface eons ago.

"In contrast to most volcanic deposits, the melt inclusions are encased
in crystals that prevent the escape of water and other volatiles during
eruption. These samples provide the best window we have to the amount of
water in the interior of the Moon," said James Van Orman of Case Western
Reserve University, a member of the science team. The paper's authors
are Hauri; Thomas Weinreich, Alberto Saal and Malcolm Rutherford from
Brown University; and Van Orman.

Compared with meteorites, Earth and the other inner planets of our solar
system contain relatively low amounts of water and volatile elements,
which were not abundant in the inner solar system during planet
formation. The even lower quantites of these volatile elements found on
the Moon has long been claimed as evidence that it must have formed
following a high-temperature, catastrophic giant impact. But this new
research shows that aspects of this theory must be reevaluated. The
study also provides new momentum for returning similar samples from
other planetary bodies in the solar system.

"Water plays a critical role in determining the tectonic behavior of
planetary surfaces, the melting point of planetary interiors, and the
location and eruptive style of planetary volcanoes," said Hauri, a
geochemist with Carnegie's Department of Terrestrial Magnetism (DTM).
"We can conceive of no sample type that would be more important to
return to Earth than these volcanic glass samples ejected by explosive
volcanism, which have been mapped not only on the Moon but throughout
the inner solar system."

Three years ago the same team, in a study led by Saal, reported the
first evidence for the presence of water in lunar volcanic glasses and
applied magma degassing models to estimate how much water was originally
in the magmas before eruption. Building on that study, Weinreich, a
Brown University undergraduate, found the melt inclusions, allowing the
team to measure the pre-eruption concentration of water in the magma and
estimate the amount of water in the Moon's interior.

"The bottom line," said Saal, "is that in 2008, we said the primitive
water content in the lunar magmas should be similar to the water content
in lavas coming from the Earth's depleted upper mantle. Now, we have
proven that is indeed the case."

The study also puts a new twist on the origin of water ice detected in
craters at the lunar poles by several recent NASA missions. The ice has
been attributed to comet and meteoroid impacts, but it is possible that
some of this ice could have come from the water released by past
eruptions of lunar magmas.

These findings should also be taken into account when analyzing samples
from other planetary bodies in our solar system. The paper's authors say
these results show that their method of analysis is the only way to
accurately and directly determine the water content of a planet's
interior. "
http://www.eurekalert.org/pub_releas...-lwb052011.php

Dear Yousuf Khan:

On May 27, 11:15*am, Yousuf Khan wrote:
....
Compared with meteorites, Earth and the other inner
planets of our solar system contain relatively low
amounts of water and volatile elements, which were
not abundant in the inner solar system during planet
formation. The even lower quantites of these volatile
elements found on the Moon has long been claimed
as evidence that it must have formed following a
high-temperature, catastrophic giant impact. But this
new research shows that aspects of this theory must
be reevaluated. The study also provides new
momentum for returning similar samples from other
planetary bodies in the solar system.

So the Moon did not coalesce from a debris field, but lobed off from
Earth after a failry gentle merging of Earth and Theia. And/or the
water was simply tied up in hydrates in the original rock, and we
still don't know.

David A. Smith

On 27/05/2011 3:37 PM, dlzc wrote:
So the Moon did not coalesce from a debris field, but lobed off from
Earth after a failry gentle merging of Earth and Theia. And/or the
water was simply tied up in hydrates in the original rock, and we
still don't know.

David A. Smith

Or the Moon formed alongside the Earth in parallel, much like the moons
of all of the other planets.

Yousuf Khan

Dear Yousuf Khan:

On May 27, 2:10*pm, Yousuf Khan wrote:
On 27/05/2011 3:37 PM,dlzcwrote:

So the Moon did not coalesce from a debris field, but
lobed off from Earth after a [fairly] gentle merging of
Earth and Theia. *And/or the water was simply tied up
in hydrates in the original rock, and we still don't know.

Or the Moon formed alongside the Earth in parallel,
much like the moons of all of the other planets.

Earth 5515 kg/m^3
Moon 3350 kg/m^3

Jupiter 1326 kg/m^3
Ganymede 1940 kg/m^3

Unlikely the Earth and Moon formed in parallel from the same stuff...
some process sorted the lighter stuff out to the Moon. Being liquid
at lower temperatures will do that, as will other processes involving
variable viscosity.

David A. Smith

On 5/27/2011 6:01 PM, dlzc wrote:
On May 27, 2:10 pm, Yousuf wrote:
Or the Moon formed alongside the Earth in parallel,
much like the moons of all of the other planets.

Earth 5515 kg/m^3
Moon 3350 kg/m^3

Jupiter 1326 kg/m^3
Ganymede 1940 kg/m^3

Unlikely the Earth and Moon formed in parallel from the same stuff...
some process sorted the lighter stuff out to the Moon. Being liquid
at lower temperatures will do that, as will other processes involving
variable viscosity.

I don't think the relative density of the worlds is any indication of
the their common location of origin. Afterall, Jupiter is a gas planet
and Ganymede is a solid moon, but they both have pretty close to the
same density. Also Venus and Mercury have pretty much the same density
as Earth does, but we know they didn't form in the same regions of the
solar system. Mars and the Moon have similar densities to each other also.

The following article has some good discussion about the possible
alternatives to the Giant Impact hypothesis of the Moon.

The Moon gets wetter
http://www.astronomynow.com/news/n1105/27moon/

One solution they suggest is that either the giant impact was *more*
energetic than thought, and another was that it was *less* energetic
than thought:

"But the giant impact does not predict such a high lunar water content, because the impact is thought to result in almost total melting of the material that goes into orbit around the Earth post-impact, and such hot material in the vacuum of space will result in total dehydration," Hauri tells Astronomy Now. "There are two ways out of this. One is that we might be over-estimating the amount of energy in a giant impact, and perhaps some part of the Earth was incorporated into the Moon in a solid unmelted state, and that's why we observe such high water contents and similarly Earth-like amounts of sulfur, fluorine and chlorine. The other is that we might be under-estimating giant impact energy, and maybe the material that was ejected was so hot that it formed an atmosphere of silicate vapor that enclosed both the Earth and proto-Moon, which would be very dense and might be enough to trap water and other volatiles for a long enough period of time that the Earth exchanged vola
tile material with the proto-Moon."

This finding also seems to effectively rule out the idea that most of
the water on Earth came from comets. If it came from comets, then the
Moon would get much less water than the Earth, not nearly the same
amount per relative mass:

Despite the uncertainty Hauri thinks that their findings can at least rule out some assumptions about the Earth getting much of its oceans and atmosphere from water-rich comets that struck our planet after the impact. "This material would of course also hit the Moon, but the Earth, by virtue of its larger diameter and higher gravity, would incorporate 20-40 times more of this stuff than the Moon. So this idea would predict a Moon with 20-40 times lower water than the Earth and not the same amount, as we have estimated," he says.

I don't know what the best alternative to the Giant Impact/Theia
hypothesis is. Maybe it's the giant blob hypothesis where a big blob of
Earth material simply fissioned off the Earth and entered orbit around
it. The Earth would have to be rotating extremely fast for something
like that to happen, I gather. There is also the possibility that the
Moon was captured by the Earth's gravity. But what could create the
braking force needed to capture the Moon? The Earth's atmosphere
would've had to be extremely large back then to create such a braking
force, making the Earth more like Neptune and Uranus.

Maybe another possibility is that there was still an impact on the
Earth, but not of a Mars-sized body, but of a Moon-sized body -- in fact
the exact Moon that we have today. It was a low-speed impact, it didn't
result in a complete melting of either body, and the Moon just bounced
off the Earth. That way, the Earth's own body supplied the braking force
to the Moon during capture, no large atmosphere needed. There would be
some minor impact scarring on both surfaces, and they would both heal as
magma flow equalized the surfaces. During the period that the bodies
touched, they transferred some crustal & mantle material to the Moon,
including water.

Yousuf Khan

On May 27, 2:10*pm, Yousuf Khan wrote:
On 27/05/2011 3:37 PM, dlzc wrote:

So the Moon did not coalesce from a debris field, but lobed off from
Earth after a failry gentle merging of Earth and Theia. *And/or the
water was simply tied up in hydrates in the original rock, and we
still don't know.

David A. Smith

Or the Moon formed alongside the Earth in parallel, much like the moons
of all of the other planets.

* * * * Yousuf Khan

A lot of other moons were captured, so why not ours?

http://www.wanttoknow.info/
http://translate.google.com/#
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”

On May 27, 3:01*pm, dlzc wrote:
Dear Yousuf Khan:

On May 27, 2:10*pm, Yousuf Khan wrote:

On 27/05/2011 3:37 PM,dlzcwrote:

So the Moon did not coalesce from a debris field, but
lobed off from Earth after a [fairly] gentle merging of
Earth and Theia. *And/or the water was simply tied up
in hydrates in the original rock, and we still don't know.

Or the Moon formed alongside the Earth in parallel,
much like the moons of all of the other planets.

Earth 5515 kg/m^3
Moon 3350 kg/m^3

Jupiter 1326 kg/m^3
Ganymede 1940 kg/m^3

Unlikely the Earth and Moon formed in parallel from the same stuff...
some process sorted the lighter stuff out to the Moon. *Being liquid
at lower temperatures will do that, as will other processes involving
variable viscosity.

David A. Smith

Moons can be captured.

What created that 2500 km crater?

http://www.wanttoknow.info/
http://translate.google.com/#
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”

On May 27, 10:15*pm, Yousuf Khan wrote:
On 5/27/2011 6:01 PM, dlzc wrote:

On May 27, 2:10 pm, Yousuf *wrote:
Or the Moon formed alongside the Earth in parallel,
much like the moons of all of the other planets.

Earth 5515 kg/m^3
Moon 3350 kg/m^3

Jupiter 1326 kg/m^3
Ganymede 1940 kg/m^3

Unlikely the Earth and Moon formed in parallel from the same stuff...
some process sorted the lighter stuff out to the Moon. *Being liquid
at lower temperatures will do that, as will other processes involving
variable viscosity.

I don't think the relative density of the worlds is any indication of
the their common location of origin. Afterall, Jupiter is a gas planet
and Ganymede is a solid moon, but they both have pretty close to the
same density. Also Venus and Mercury have pretty much the same density
as Earth does, but we know they didn't form in the same regions of the
solar system. Mars and the Moon have similar densities to each other also..

The following article has some good discussion about the possible
alternatives to the Giant Impact hypothesis of the Moon.

The Moon gets wetterhttp://www.astronomynow.com/news/n1105/27moon/

One solution they suggest is that either the giant impact was *more*
energetic than thought, and another was that it was *less* energetic
than thought:

"But the giant impact does not predict such a high lunar water content, because the impact is thought to result in almost total melting of the material that goes into orbit around the Earth post-impact, and such hot material in the vacuum of space will result in total dehydration," Hauri tells Astronomy Now. "There are two ways out of this. One is that we might be over-estimating the amount of energy in a giant impact, and perhaps some part of the Earth was incorporated into the Moon in a solid unmelted state, and that's why we observe such high water contents and similarly Earth-like amounts of sulfur, fluorine and chlorine. The other is that we might be under-estimating giant impact energy, and maybe the material that was ejected was so hot that it formed an atmosphere of silicate vapor that enclosed both the Earth and proto-Moon, which would be very dense and might be enough to trap water and other volatiles for a long enough period of time that the Earth exchanged vola

tile material with the proto-Moon."

This finding also seems to effectively rule out the idea that most of
the water on Earth came from comets. If it came from comets, then the
Moon would get much less water than the Earth, not nearly the same
amount per relative mass:

Despite the uncertainty Hauri thinks that their findings can at least rule out some assumptions about the Earth getting much of its oceans and atmosphere from water-rich comets that struck our planet after the impact. "This material would of course also hit the Moon, but the Earth, by virtue of its larger diameter and higher gravity, would incorporate 20-40 times more of this stuff than the Moon. So this idea would predict a Moon with 20-40 times lower water than the Earth and not the same amount, as we have estimated," he says.

I don't know what the best alternative to the Giant Impact/Theia
hypothesis is. Maybe it's the giant blob hypothesis where a big blob of
Earth material simply fissioned off the Earth and entered orbit around
it. The Earth would have to be rotating extremely fast for something
like that to happen, I gather. There is also the possibility that the
Moon was captured by the Earth's gravity. But what could create the
braking force needed to capture the Moon? The Earth's atmosphere
would've had to be extremely large back then to create such a braking
force, making the Earth more like Neptune and Uranus.

Maybe another possibility is that there was still an impact on the
Earth, but not of a Mars-sized body, but of a Moon-sized body -- in fact
the exact Moon that we have today. It was a low-speed impact, it didn't
result in a complete melting of either body, and the Moon just bounced
off the Earth. That way, the Earth's own body supplied the braking force
to the Moon during capture, no large atmosphere needed. There would be
some minor impact scarring on both surfaces, and they would both heal as
magma flow equalized the surfaces. During the period that the bodies
touched, they transferred some crustal & mantle material to the Moon,
including water.

* * * * Yousuf Khan

Now you're getting closer to what I've been saying all along,
suggesting an icy moon capture via a lithobraking kind of glancing
blow (aka rear-ender), and the seasonal tilt causing encounter that
nailed our planet somewhat recently.

I believe that I even have samples of that paramagnetic moon basalt,
not that Earth doesn't have paramagnetic basalt of its own (just not
as dense as moon basalt).

The interior of that moon could offer an inverted density, meaning of
lower density than its surface crust of paramagnetic basalt that gets
upwards of 4.5 g/cm3. If it's crust is as thick and 100% fused as
suggested, then perhaps there some degree of porous or hollowness to
consider.

http://www.wanttoknow.info/
http://translate.google.com/#
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”

Dear Yousuf Khan:

On May 27, 10:15*pm, Yousuf Khan wrote:
On 5/27/2011 6:01 PM, dlzc wrote:

On May 27, 2:10 pm, Yousuf *wrote:
Or the Moon formed alongside the Earth in parallel,
much like the moons of all of the other planets.

Earth 5515 kg/m^3
Moon 3350 kg/m^3

Jupiter 1326 kg/m^3
Ganymede 1940 kg/m^3

Unlikely the Earth and Moon formed in parallel from
the same stuff... some process sorted the lighter stuff
out to the Moon. *Being liquid at lower temperatures
will do that, as will other processes involving variable
viscosity.

I don't think the relative density of the worlds is any
indication of the their common location of origin.

It at least allows that they were formed from the same pool of raw
materials, in a single process.

Afterall, Jupiter is a gas planet and Ganymede is a solid
moon, but they both have pretty close to the same density.

Meaning that either they likely formed from the same protomatter pool.

Also Venus and Mercury have pretty much the same density
as Earth does,

There are a couple of asteroids that have this too. We need to be
visiting those with probes.

but we know they didn't form in the same regions of the
solar system. Mars and the Moon have similar densities
to each other also.

The following article has some good discussion about the
possible alternatives to the Giant Impact hypothesis of the
Moon.

The Moon gets wetter
http://www.astronomynow.com/news/n1105/27moon/

One solution they suggest is that either the giant impact
was *more* energetic than thought, and another was that
it was *less* energetic than thought:

"But the giant impact does not predict such a high lunar
water content, because the impact is thought to result in
almost total melting of the material that goes into orbit
around the Earth post-impact, and such hot material in the
vacuum of space will result in total dehydration," Hauri
tells Astronomy Now. "There are two ways out of this. One
is that we might be over-estimating the amount of energy
in a giant impact, and perhaps some part of the Earth was
incorporated into the Moon in a solid unmelted state, and
that's why we observe such high water contents and
similarly Earth-like amounts of sulfur, fluorine and chlorine.
The other is that we might be under-estimating giant impact
energy, and maybe the material that was ejected was so hot
that it formed an atmosphere of silicate vapor that enclosed
both the Earth and proto-Moon, which would be very dense
and might be enough to trap water and other volatiles for a
long enough period of time that the Earth exchanged
volatile material with the proto-Moon."

The latter is very unlikely, or we'd have more stuff in Trojans with
Earth around the Sun.

This finding also seems to effectively rule out the idea that
most of the water on Earth came from comets. If it came
from comets, then the Moon would get much less water
than the Earth, not nearly the same amount per relative
mass:

Despite the uncertainty Hauri thinks that their findings
can at least rule out some assumptions about the Earth
getting much of its oceans and atmosphere from water-rich
comets that struck our planet after the impact. "This
material would of course also hit the Moon, but the Earth, by
virtue of its larger diameter and higher gravity, would
incorporate 20-40 times more of this stuff than the Moon. So
this idea would predict a Moon with 20-40 times lower water
than the Earth and not the same amount, as we have
estimated," he says.

I don't know what the best alternative to the Giant Impact
/ Theia hypothesis is. Maybe it's the giant blob hypothesis
where a big blob of Earth material simply fissioned off the
Earth and entered orbit around it.

.... after a low energy merging of two bodies, with a net differential
momentum. One of the bodies arrived from slightly above / below
plane...

The Earth would have to be rotating extremely fast for
something like that to happen, I gather.

They've done spinning water blobs in ISS, and I don't think it has to
be all that fast, with an initial upset. The Earth was still spinning
with something like 16 hour days 1.8 billion years after an Earth was
present. I think we had the necessary rotation.

There is also the possibility that the Moon was captured
by the Earth's gravity. But what could create the braking
force needed to capture the Moon?

Precisely. Now it could have been trojan, and we simply caught it or
it caught us. Just as in a few billion years we will lose it again as
it recedes. But then it should be denser.

The Earth's atmosphere would've had to be extremely
large back then to create such a braking force, making
the Earth more like Neptune and Uranus.

Maybe another possibility is that there was still an
impact on the Earth, but not of a Mars-sized body, but
of a Moon-sized body -- in fact the exact Moon that we
have today. It was a low-speed impact, it didn't result
in a complete melting of either body, and the Moon just
bounced off the Earth. That way, the Earth's own body
supplied the braking force to the Moon during capture,
no large atmosphere needed. There would be some
minor impact scarring on both surfaces, and they would
both heal as magma flow equalized the surfaces. During
the period that the bodies touched, they transferred some
crustal & mantle material to the Moon, including water.

Something like that sounds most likely, but I expect both bodies ended
up fully merged, and primarily liquid-liquid transfer occurred.

David A. Smith

On May 29, 8:47*am, dlzc wrote:
Dear Yousuf Khan:

On May 27, 10:15*pm, Yousuf Khan wrote:









On 5/27/2011 6:01 PM, dlzc wrote:

On May 27, 2:10 pm, Yousuf *wrote:
Or the Moon formed alongside the Earth in parallel,
much like the moons of all of the other planets.

Earth 5515 kg/m^3
Moon 3350 kg/m^3

Jupiter 1326 kg/m^3
Ganymede 1940 kg/m^3

Unlikely the Earth and Moon formed in parallel from
the same stuff... *some process sorted the lighter stuff
out to the Moon. *Being liquid at lower temperatures
will do that, as will other processes involving variable
viscosity.

I don't think the relative density of the worlds is any
indication of the their common location of origin.

It at least allows that they were formed from the same pool of raw
materials, in a single process.

Afterall, Jupiter is a gas planet and Ganymede is a solid
moon, but they both have pretty close to the same density.

Meaning that either they likely formed from the same protomatter pool.

Also Venus and Mercury have pretty much the same density
as Earth does,

There are a couple of asteroids that have this too. *We need to be
visiting those with probes.

but we know they didn't form in the same regions of the
solar system. Mars and the Moon have similar densities
to each other also.

The following article has some good discussion about the
possible alternatives to the Giant Impact hypothesis of the
Moon.

The Moon gets wetter

http://www.astronomynow.com/news/n1105/27moon/











One solution they suggest is that either the giant impact
was *more* energetic than thought, and another was that
it was *less* energetic than thought:

"But the giant impact does not predict such a high lunar
water content, because the impact is thought to result in
almost total melting of the material that goes into orbit
around the Earth post-impact, and such hot material in the
vacuum of space will result in total dehydration," Hauri
tells Astronomy Now. "There are two ways out of this. One
is that we might be over-estimating the amount of energy
in a giant impact, and perhaps some part of the Earth was
incorporated into the Moon in a solid unmelted state, and
that's why we observe such high water contents and
similarly Earth-like amounts of sulfur, fluorine and chlorine.
The other is that we might be under-estimating giant impact
energy, and maybe the material that was ejected was so hot
that it formed an atmosphere of silicate vapor that enclosed
both the Earth and proto-Moon, which would be very dense
and might be enough to trap water and other volatiles for a
long enough period of time that the Earth exchanged
volatile material with the proto-Moon."

The latter is very unlikely, or we'd have more stuff in Trojans with
Earth around the Sun.









This finding also seems to effectively rule out the idea that
most of the water on Earth came from comets. If it came
from comets, then the Moon would get much less water
than the Earth, not nearly the same amount per relative
mass:

Despite the uncertainty Hauri thinks that their findings
can at least rule out some assumptions about the Earth
getting much of its oceans and atmosphere from water-rich
comets that struck our planet after the impact. "This
material would of course also hit the Moon, but the Earth, by
virtue of its larger diameter and higher gravity, would
incorporate 20-40 times more of this stuff than the Moon. So
this idea would predict a Moon with 20-40 times lower water
than the Earth and not the same amount, as we have
estimated," he says.

I don't know what the best alternative to the Giant Impact
/ Theia hypothesis is. Maybe it's the giant blob hypothesis
where a big blob of Earth material simply fissioned off the
Earth and entered orbit around it.

... after a low energy merging of two bodies, with a net differential
momentum. *One of the bodies arrived from slightly above / below
plane...

The Earth would have to be rotating extremely fast for
something like that to happen, I gather.

They've done spinning water blobs in ISS, and I don't think it has to
be all that fast, with an initial upset. *The Earth was still spinning
with something like 16 hour days 1.8 billion years after an Earth was
present. *I think we had the necessary rotation.

There is also the possibility that the Moon was captured
by the Earth's gravity. But what could create the braking
force needed to capture the Moon?

Precisely. *Now it could have been trojan, and we simply caught it or
it caught us. *Just as in a few billion years we will lose it again as
it recedes. *But then it should be denser.









The Earth's atmosphere would've had to be extremely
large back then to create such a braking force, making
the Earth more like Neptune and Uranus.

Maybe another possibility is that there was still an
impact on the Earth, but not of a Mars-sized body, but
of a Moon-sized body -- in fact the exact Moon that we
have today. It was a low-speed impact, it didn't result
in a complete melting of either body, and the Moon just
bounced off the Earth. That way, the Earth's own body
supplied the braking force to the Moon during capture,
no large atmosphere needed. There would be some
minor impact scarring on both surfaces, and they would
both heal as magma flow equalized the surfaces. During
the period that the bodies touched, they transferred some
crustal & mantle material to the Moon, including water.

Something like that sounds most likely, but I expect both bodies ended
up fully merged, and primarily liquid-liquid transfer occurred.

David A. Smith

The extremely nearby and massive asteroid Cruithne is supposedly only
worth 2 g/cm3, and the surface of our physically dark and paramagnetic
moon has basalt worth 4.5 g/cm3, and otherwise Venus has considerably
more surface thorium than Earth. How does either of those add up to
being similar to Earth?

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Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”