The moon

Does anybody have any info on how far the moon is moving away from the
earth each year and how this figure would have changed over time.
------
D. Haas

"Consistency requires you be as ignorant today as you were a year ago."
Bernard Berenson

On Sun, 03 Aug 2003 20:30:40 GMT, David Haas wrote:

Does anybody have any info on how far the moon is moving away from the
earth each year and how this figure would have changed over time.

I'm sure I read somewhere it was something like an inch or two per
year (or 100 years?). And that eventually it would become free from
earths attraction and fly off into space. At which time the earth
wouldn't be a good place to be.

Perhaps someone else will be able to add some facts to this
explanation, I'm going on memory and don't claim to be very
knowledgeable on this subject.

Andrew

Do you need a handyman service? Check out our
web site at http://www.handymac.co.uk

On Sun, 03 Aug 2003 22:05:12 +0100, Andrew McKay
wrote:

On Sun, 03 Aug 2003 20:30:40 GMT, David Haas wrote:

Does anybody have any info on how far the moon is moving away from the
earth each year and how this figure would have changed over time.

I'm sure I read somewhere it was something like an inch or two per
year (or 100 years?). And that eventually it would become free from
earths attraction and fly off into space. At which time the earth
wouldn't be a good place to be.

....
Andrew

Do you need a handyman service? Check out our
web site at http://www.handymac.co.uk

Moon is receeding from Earth at a speed of 37mm per year (about an inch and a
half). Moon is currently 371 167 kM from Earth but in five billions years, when
the Sun will turn to a red SuperGiant, Moon will have moved away by 185 000 kM
for a total of 556 167 kM.

This is not a big difference. Moon will never be free from Earth, everythings
will be vaporised long before that...

Sleep well!

Benoît Morrissette...

Some have suggested, I think, that as it moves away the stresses will
make the moon shatter into a ring like Saturn's.
Is this correct?
The bigger problem is the effect of tidal forces which give momentum to
the moon - to slow down the moon's receding we could for example build a
huge barrage across the Pacific to reduce the loss of momentum...
[This was in a Disacovery programme on TV not so long ago.]

Benoit Morrissette wrote:
On Sun, 03 Aug 2003 22:05:12 +0100, Andrew McKay
wrote:


On Sun, 03 Aug 2003 20:30:40 GMT, David Haas wrote:


Does anybody have any info on how far the moon is moving away from the
earth each year and how this figure would have changed over time.

I'm sure I read somewhere it was something like an inch or two per
year (or 100 years?). And that eventually it would become free from
earths attraction and fly off into space. At which time the earth
wouldn't be a good place to be.


...

Andrew

Do you need a handyman service? Check out our
web site at http://www.handymac.co.uk


Moon is receeding from Earth at a speed of 37mm per year (about an inch and a
half). Moon is currently 371 167 kM from Earth but in five billions years, when
the Sun will turn to a red SuperGiant, Moon will have moved away by 185 000 kM
for a total of 556 167 kM.

This is not a big difference. Moon will never be free from Earth, everythings
will be vaporised long before that...

Sleep well!

Benoît Morrissette...

"Carusus" wrote in message
...
Some have suggested, I think, that as it moves away the stresses will
make the moon shatter into a ring like Saturn's.
Is this correct?

It could break up if it approached closer, within the
Roche Limit. It's perfectly safe (from breakup due
to tidal stress) as it recedes.

David Haas wrote in message ...
Does anybody have any info on how far the moon is moving away from the
earth each year and how this figure would have changed over time.
------
D. Haas

"Consistency requires you be as ignorant today as you were a year ago."
Bernard Berenson

In the context of refuting one of the many invalid "young earth"
arguments, there's some good information at

http://www.talkorigins.org/faqs/moonrec.html

The moon is receding at about an inch and a half per year. This is
faster than its average recession over time. It's faster today
because of the mechanism of recession...

Basically, the earth's rotation is slowing slightly thanks to tidal
force from the moon. The rotational energy has to go someplace: that
someplace is into the moon's orbit. When you put energy into an
orbit, you raise it.

The biggest reason the tides slow the earth is that the earth's oceans
bulge toward and away from the moon, and this bulge slams into the
eastern edge of each continent as the earth spins. This produces a
drag on the earth's rotation.

During a significant fraction of Earth's history, there was only one
big continent. During those times, each tidal bulge hits an eastern
coastline only once per day. Currently, however, we have two
north-pole-to-south-pole continental masses, meaning that the tidal
bulges hit the eastern coastlines twice each day, and the drag effect
of this particular process is more or less twice what it has
historically most often been.

Carusus wrote in alt.astronomy:

Some have suggested, I think, that as it moves

....closer, not...

away the stresses will
make the moon shatter into a ring like Saturn's.
Is this correct?

Here's two on the Roche Limit:

http://pegasus.phast.umass.edu/a100/handouts/roche.html
http://zebu.uoregon.edu/~js/glossary/roche_limit.html


--
CeeBee


Uxbridge: "By God, sir, I've lost my leg!"
Wellington: "By God, sir, so you have!"


Google CeeBee @ www.geocities.com/ceebee_2

Is that correct? Surely the total momentum of the wavefronts will remain
the same?

eyelessgame wrote:

David Haas wrote in message ...

Does anybody have any info on how far the moon is moving away from the
earth each year and how this figure would have changed over time.
------
D. Haas

"Consistency requires you be as ignorant today as you were a year ago."
Bernard Berenson


In the context of refuting one of the many invalid "young earth"
arguments, there's some good information at

http://www.talkorigins.org/faqs/moonrec.html

The moon is receding at about an inch and a half per year. This is
faster than its average recession over time. It's faster today
because of the mechanism of recession...

Basically, the earth's rotation is slowing slightly thanks to tidal
force from the moon. The rotational energy has to go someplace: that
someplace is into the moon's orbit. When you put energy into an
orbit, you raise it.

The biggest reason the tides slow the earth is that the earth's oceans
bulge toward and away from the moon, and this bulge slams into the
eastern edge of each continent as the earth spins. This produces a
drag on the earth's rotation.

During a significant fraction of Earth's history, there was only one
big continent. During those times, each tidal bulge hits an eastern
coastline only once per day. Currently, however, we have two
north-pole-to-south-pole continental masses, meaning that the tidal
bulges hit the eastern coastlines twice each day, and the drag effect
of this particular process is more or less twice what it has
historically most often been.

Is that correct? Surely the total momentum of the wavefronts will remain
the same?

eyelessgame wrote:

David Haas wrote in message ...

Does anybody have any info on how far the moon is moving away from the
earth each year and how this figure would have changed over time.
------
D. Haas

"Consistency requires you be as ignorant today as you were a year ago."
Bernard Berenson


In the context of refuting one of the many invalid "young earth"
arguments, there's some good information at

http://www.talkorigins.org/faqs/moonrec.html

The moon is receding at about an inch and a half per year. This is
faster than its average recession over time. It's faster today
because of the mechanism of recession...

Basically, the earth's rotation is slowing slightly thanks to tidal
force from the moon. The rotational energy has to go someplace: that
someplace is into the moon's orbit. When you put energy into an
orbit, you raise it.

The biggest reason the tides slow the earth is that the earth's oceans
bulge toward and away from the moon, and this bulge slams into the
eastern edge of each continent as the earth spins. This produces a
drag on the earth's rotation.

During a significant fraction of Earth's history, there was only one
big continent. During those times, each tidal bulge hits an eastern
coastline only once per day. Currently, however, we have two
north-pole-to-south-pole continental masses, meaning that the tidal
bulges hit the eastern coastlines twice each day, and the drag effect
of this particular process is more or less twice what it has
historically most often been.

"Carusus" wrote in message
...
Is that correct? Surely the total momentum of the wavefronts will remain
the same?

Friction on the continental shelves dissipates energy
as heat.