Source of dirt on the moon? (bootprint...)

This has bothered me since 6th grade science class, when we covered
weathering and soil formation. I thought of that bootprint. After class
I asked the teacher if the moon had an any atmosphere at all. (It was a
leading question.) He of course said no. I asked him where the dirt on
the moon came from. He thought the question was good, and didn't have
an answer.

Well, now there is a forum for me to get a proper answer to this
question.

Every time I see a picture of that bootprint it bothers me. It seems to
me that the surface of the moon would have been molten at the time of
it's formation. There is no weather (or life) to break down the rock.
So maybe dust settled over a few billion years. So why didn't it settle
on the small to large rocks seen in other pictures? The dirt around
those rocks is not disturbed - so the rocks didn't fall on existing
dirt. The only thing I can think of seems totally wrong - and that's
that maybe the subatomic particles in the solar wind are capable of
blowing the dirt off the rocks. (Gees that's sounds bad.) We are
protected by our magnetic field, and that "wind" is apparently pretty
fierce - but having subatomic particles moving dirt just doesn't fly
with me.

wrote:
This has bothered me since 6th grade science class, when we covered
weathering and soil formation. I thought of that bootprint. After class
I asked the teacher if the moon had an any atmosphere at all. (It was a
leading question.) He of course said no. I asked him where the dirt on
the moon came from. He thought the question was good, and didn't have
an answer.

Well, now there is a forum for me to get a proper answer to this
question.

Every time I see a picture of that bootprint it bothers me. It seems to
me that the surface of the moon would have been molten at the time of
it's formation. There is no weather (or life) to break down the rock.
So maybe dust settled over a few billion years. So why didn't it settle
on the small to large rocks seen in other pictures? The dirt around
those rocks is not disturbed - so the rocks didn't fall on existing
dirt. The only thing I can think of seems totally wrong - and that's
that maybe the subatomic particles in the solar wind are capable of
blowing the dirt off the rocks. (Gees that's sounds bad.) We are
protected by our magnetic field, and that "wind" is apparently pretty
fierce - but having subatomic particles moving dirt just doesn't fly
with me.


Similar soil (dust) on many other bodies too.
http://antwrp.gsfc.nasa.gov/apod/ap001027.html

o weather of rocks from heat extremes
o meteoric dust (millions of tons fall on the earth each year)
o debris from impacts of all sizes

Dear david_l:

wrote in message
oups.com...
....
Every time I see a picture of that bootprint it bothers me.
It seems to me that the surface of the moon would have
been molten at the time of it's formation.

Right...

There is no weather (or life) to break down the rock.

There is weather. There is a 200 C° temperature swing every
month for more than a billion years. Much less than that cracks
rocks here on Earth. There is a hail of large and small
meteorites that impact the surface, spraying material around.
And as you note, the Moon has gravity and can collect anything
that passes slowly enough.

So maybe dust settled over a few billion years. So
why didn't it settle on the small to large rocks
seen in other pictures?

Didn't it? Did you see someone trying to dust off the rocks and
there wasn't any?

The dirt around those rocks is not disturbed - so
the rocks didn't fall on existing dirt.

Or did fall on existing "dirt", and more "dirt" came down later.

The only thing I can think of seems totally wrong -
and that's that maybe the subatomic particles in
the solar wind are capable of blowing the dirt off
the rocks. (Gees that's sounds bad.)

Sounds bad, but why not? There is no atmosphere to speak of, and
days are a week long. Solar wind will not be deflected by any
magnetic field...

We are protected by our magnetic field,

No. The Earths' magnetic field only serves to gather *more*
material. Witness the Aurora.

and that "wind" is apparently pretty fierce - but
having subatomic particles moving dirt just
doesn't fly with me.

Scientists move tiny latex spheres around using only a laser.
Your common sense is trained by what you immerse it in. Given a
long enough time, the tiniest breeze could eventually clear a
surface.

David A. Smith

wrote in news:1149566124.900379.251520
@g10g2000cwb.googlegroups.com:

This has bothered me since 6th grade science class, when we covered
weathering and soil formation. I thought of that bootprint. After class
I asked the teacher if the moon had an any atmosphere at all. (It was a
leading question.) He of course said no. I asked him where the dirt on
the moon came from. He thought the question was good, and didn't have
an answer.

Well, now there is a forum for me to get a proper answer to this
question.

Every time I see a picture of that bootprint it bothers me. It seems to
me that the surface of the moon would have been molten at the time of
it's formation. There is no weather (or life) to break down the rock.

The moon is hit my myriad small meteors which kick up dust as well as
produce new dust. These type of small particles don't hit the Earth's
surface because they are destroyed by the Earth's atmosphere (shooting
stars).

Klazmon.
SNIP

wrote:
This has bothered me since 6th grade science class, when we covered
weathering and soil formation. I thought of that bootprint. After class
I asked the teacher if the moon had an any atmosphere at all. (It was a
leading question.) He of course said no. I asked him where the dirt on
the moon came from. He thought the question was good, and didn't have
an answer.
There is a phenomona when the lunar surface changes from day to night
(?) where there is a electrostatic/magnetic change .. or change in
charge on the dust particle and the moon dust flies all over the place.

Appararently it is "supposed" to be a big problem. The stuff gets into
everything.

I read about it on some physics websites a short while back.


I'm sorry that I can't be more specific. ... Even the description of
the phenomenon escapes me. ... I've forgotten.

Cordially,

RL

An old Apollo experiment is telling researchers
something new and surprising about the moon.

http://science.nasa.gov/headlines/y2....htm?list89139

December 7, 2005: Every lunar morning, when the sun first peeks over
the dusty soil of the moon after two weeks of frigid lunar night, a
strange storm stirs the surface.

The next time you see the moon, trace your finger along the terminator,
the dividing line between lunar night and day. That's where the storm
is. It's a long and skinny dust storm, stretching all the way from the
north pole to the south pole, swirling across the surface, following
the terminator as sunrise ceaselessly sweeps around the moon.

See: http://science.nasa.gov/headlines/y2....htm?list89139

"Sam Wormley" wrote in message
news:Ng8hg.19521$1i1.13869@attbi_s72...

An old Apollo experiment is telling researchers
something new and surprising about the moon.

http://science.nasa.gov/headlines/y2....htm?list89139

December 7, 2005: Every lunar morning, when the sun first peeks over
the dusty soil of the moon after two weeks of frigid lunar night, a
strange storm stirs the surface.

The next time you see the moon, trace your finger along the terminator,
the dividing line between lunar night and day. That's where the storm
is. It's a long and skinny dust storm, stretching all the way from the
north pole to the south pole, swirling across the surface, following
the terminator as sunrise ceaselessly sweeps around the moon.

See:
http://science.nasa.gov/headlines/y2....htm?list89139

Very interesting, thankyou.

wrote in message
oups.com...
| This has bothered me since 6th grade science class, when we covered
| weathering and soil formation. I thought of that bootprint. After class
| I asked the teacher if the moon had an any atmosphere at all. (It was a
| leading question.) He of course said no. I asked him where the dirt on
| the moon came from. He thought the question was good, and didn't have
| an answer.
|
| Well, now there is a forum for me to get a proper answer to this
| question.
|
| Every time I see a picture of that bootprint it bothers me. It seems to
| me that the surface of the moon would have been molten at the time of
| it's formation. There is no weather (or life) to break down the rock.

There are impact craters and volcanic craters. The early moon cooled
faster than the Earth, but it was once volcanic and we have evidence
of ash on Earth. Thus the moon was covered in dust soon after it's crust
cooled.

| So maybe dust settled over a few billion years. So why didn't it settle
| on the small to large rocks seen in other pictures?

The large rock came from an impact crater that occured a million years
after the ash settled, and the crater is 500 km away.



The dirt around
| those rocks is not disturbed - so the rocks didn't fall on existing
| dirt.

Yes they did. The dust doesn't move without air to blow it away, it only
moves by direct collision. Drop a pebble on a sandy beach beside your own
footprints and see. Make certain you leave clear footprints, too.
The very fact that the fooprints exist in dry sand shows that the
sand doesn't get displaced except by direct contact.
Androcles



The only thing I can think of seems totally wrong - and that's
| that maybe the subatomic particles in the solar wind are capable of
| blowing the dirt off the rocks. (Gees that's sounds bad.) We are
| protected by our magnetic field, and that "wind" is apparently pretty
| fierce - but having subatomic particles moving dirt just doesn't fly
| with me.
|

Sam Wormley wrote in
news:Ng8hg.19521$1i1.13869@attbi_s72:


An old Apollo experiment is telling researchers
something new and surprising about the moon.

http://science.nasa.gov/headlines/y2...rms.htm?list89
139

December 7, 2005: Every lunar morning, when the sun first peeks over
the dusty soil of the moon after two weeks of frigid lunar night, a
strange storm stirs the surface.

The next time you see the moon, trace your finger along the
terminator, the dividing line between lunar night and day. That's
where the storm is. It's a long and skinny dust storm, stretching all
the way from the north pole to the south pole, swirling across the
surface, following the terminator as sunrise ceaselessly sweeps around
the moon.

See:
http://science.nasa.gov/headlines/y2....htm?list89139

So I wonder if those footprints have filled in and disappeared yet...

-- Bob

On Tue, 06 Jun 2006 16:49:52 +1200, Llanzlan Klazmon wrote:

wrote in news:1149566124.900379.251520
@g10g2000cwb.googlegroups.com:

This has bothered me since 6th grade science class, when we covered
weathering and soil formation. I thought of that bootprint. After class
I asked the teacher if the moon had an any atmosphere at all. (It was a
leading question.) He of course said no. I asked him where the dirt on
the moon came from. He thought the question was good, and didn't have
an answer.

Well, now there is a forum for me to get a proper answer to this
question.

Every time I see a picture of that bootprint it bothers me. It seems to
me that the surface of the moon would have been molten at the time of
it's formation. There is no weather (or life) to break down the rock.

The moon is hit my myriad small meteors which kick up dust as well as
produce new dust. These type of small particles don't hit the Earth's
surface because they are destroyed by the Earth's atmosphere (shooting
stars).

Klazmon.
SNIP

I'm not so sure of that, here on Earth. Granted, the mostly-carbon
meteorites will burn up in the atmosphere (which of course creates carbon
dioxide) but the iron ones will create iron oxide, which will probably
float up there for awhile then come down as some sort of rusty dust.
Ice-based meteorites would eventually come down as rain, presumably.
I'm probably being slightly pedantic, though.

Of course the bigger ones will thump anything in their way (hopefully not
including humans) and then be picked up as collector's items. :-)

Your answer is otherwise a good one, and apparently the lunar regolith is
interesting stuff, about the consistency of talcum powder -- and probably
will bedevil any permanent base-dweller deciding to go out for a walk. :-)

http://en.wikipedia.org/wiki/Geology_of_the_Moon

I'll admit to some curiosity as to whether the astronauts ever complained
about cleaning the stuff off their suits.

[followups to sci.physics, mostly because I post there]

--
#191,
It's still legal to go .sigless.