[Seany (OP)]

Apart from there being no tides of course..

I also read that there would be no more evolution, somehow.. Because apparently we evolved from a fish or something, and we only got exposed outside or something because of the tides! But I don't think it makes much senser!

Would there be a catastrophe if one day the moon decided to fly off? []

[turnipsock]

The Earth would probably fly into the sun.

I think the earth and moon are a bit like a hammer thrower, so when the hammer (moon) is thrown, the thrower (earth) falls backwards.

[ukmicky]

The earth and moon are linked to each other and orbit the sun as one body.

Also the moon may look  large but it contains very little mass compared to the earth and therefore if the moon were to dissapear the resulting loss of mass from the earth moon system would only cause a very small and minor change to the earths orbital characteristics around the sun.

If the moon were to dissapear it would however cause chaos to the earths weather systems as the moon helps stabilize the tilt of the earth.

[lyner]

The Moon wouldn't  'decide' to fly off; it would need to be pulled off by some massive engine. If it did it quickly enough, the orbit of Earth would not be perturbed a lot so things would not change a lot - only the tides. If you took time and pulled the Moon away over a long period of time, Earth's orbit could be changed a lot and  anything goes.
The orbit of the Earth Moon system would be the same as that of the Earth - the Sun being so massive, in comparison. All that counts is the present radius and speed, not the Mass. [xx(]

[ukmicky]

All that counts is the present radius and speed, not the Mass.

As the two bodies orbit around a common centre wouldnt the removal of that common centre cause a  minor change? .

[Seany (OP)]

The Earth would probably fly into the sun.

I think the earth and moon are a bit like a hammer thrower, so when the hammer (moon) is thrown, the thrower (earth) falls backwards.

The Earth would fly into the sun? I'm sure that wouldn't happen... =/

[Seany (OP)]

The Moon wouldn't  'decide' to fly off; it would need to be pulled off by some massive engine. If it did it quickly enough, the orbit of Earth would not be perturbed a lot so things would not change a lot - only the tides. If you took time and pulled the Moon away over a long period of time, Earth's orbit could be changed a lot and  anything goes.
The orbit of the Earth Moon system would be the same as that of the Earth - the Sun being so massive, in comparison. All that counts is the present radius and speed, not the Mass. [xx(]

I don't know.. I heard that the Moon is gradually moving away from the Earth, and one day it will wander off.. We're talking millions of years.

[ukmicky]

The Moon wouldn't  'decide' to fly off; it would need to be pulled off by some massive engine. If it did it quickly enough, the orbit of Earth would not be perturbed a lot so things would not change a lot - only the tides. If you took time and pulled the Moon away over a long period of time, Earth's orbit could be changed a lot and  anything goes.
The orbit of the Earth Moon system would be the same as that of the Earth - the Sun being so massive, in comparison. All that counts is the present radius and speed, not the Mass. [xx(]

I don't know.. I heard that the Moon is gradually moving away from the Earth, and one day it will wander off.. We're talking millions of years.

The moon will continue to move away from the earth as it robs energy from the earth through tidal action. The energy it gets is robbed from the spin of the earth and as a consequence the spin of the earth around its axis is slowly slowing down.

However i believe this will stop and the moon will no longer be able to rob energy from the earth and they will both show each other the same face just like how to moons rotation slowed down to a point that it now show us the same face all the time ,something like that ..

[Seany (OP)]

So the moon will never separate from us?

[ukmicky]

Dont think so. By that time anyway the sun will be no more just like the earth and moon.

[Seany (OP)]

Isn't it like 6 billion years before the sun burns off?
Also, is the burning of the sun constant?

[rosalind dna]

I can't imagine the moon flying away as you titled your thread,
Seany.
Because it is the Earth's satellite and if it could or did then the seasons as well as the tides would become chaotic and uncotrollable also I guess that the earth's pull of gravity might have something to do with it.

[ukmicky]

Isn't it like 6 billion years before the sun burns off?
Also, is the burning of the sun constant?

The moon i believe is moving away from us at present around 1 inch a year ,so in 6 billion years the moon would only be 152 400 killometers further away.

 However in reality the figure will be less than that because the further away the moon gets the less the earth feels its gravity ,so over time the ammount of energy the moon will be able rob from the earth will decrease meaning the distance that the moon is moving away each year is slowly decreasing.

[Seany (OP)]

152400 kilometres is alot!! or is that not far enough for it to come out of orbit?

[ukmicky]

Not really at present the moon is 384,402 km away from us. If you were to make the sun everlasting at some stage in the future the moon would stop moving away and the face of the earth and moon would be tidally locked just like Pluto and its moon Charon

[Seany (OP)]

But 150,000km is almost half that distance

[ukmicky]

But its no a lot as far as orbits go and also as i said it will not be that much because the distance that the moon is receding each year is decreasing.


http://www.astro.uu.nl/~strous/AA/en/antwoorden/getijden.html

http://burro.astr.cwru.edu/stu/planets_dwarf_pluto_moons.html

[lyner]

If we are talking about a simple system with just Sun, Earth and Moon the angular momentum must remain constant so, because the Sun is so massive, the orbit times should not change.
With some of these threades I can't be sure whether the simple question to the simple model is required (that should be answered first, in any case) or the clever clogs question which seeks to examine just one of the additional effects on a system. If we're talking about eons in the future, then we should include effects of other planets too.
We could try to encourage more closed questions, perhaps or, early on in threads, we could try to rephrase original questions in a more fruitful way. There can be too many open ended, rambling discussions which don't really add to the sum of human knowledge.

[Make it Lady]

So the TV programme 'Space 1999' where the moon leaves the Earth's orbit, due to an explosion on its surface, taking the people on its moon base with it is a load of old twaddle?

[lyner]

The particularly twaddlish bit was that they kept meeting people on their journey.
Any explosion that would knock the Moon out of its orbit would have to propel a lot of material in the other direction (action and reaction). Such acceleration would have left a lot of surface stuff behind, including the cast of the series, who were standing on the surface.
Not a good idea to carry these thought experiments to their logical conclusion.