Moon moving away from Earth

[Lakitu]

Hello :o)

A TV programme I watched told us that the moon is moving away from us at a rate of 3 inches or 3 centimeters (I can't remember which, sorry) per year.

Will the moon eventually be too far away from Earth to have any effect and if that does happen, I assume our oceans will become no more than a ripple, so what would that mean for life on Earth, if any?

Thanks

[fo3nix]

Yes that's true. But by the time this happens, we'll probably all be living on Mars!

[Lakitu]

I know it's not going to happen in my lifetime, but I'd still ike to know what it would mean for life on Earth...

[joggerjayne]

I heard that, Titch.

How on earth (ha ha) can we measure something that small?

So ... if I live to be 100, the Moon will be 2m further away. Should I panic?

[joggerjayne]

I just thought ... is the Moon's orbit so perfectly regular that it doesn't even vary by 3cm on each orbit?

[Lakitu]

When Neil and Buzz landed on the moon they left a reflector on it.

A couple of guys in Texas use a laser beam (said in Dr Evil accent), point it to this reflective thingy and measure the time it takes to reflect to the moon and back.

The can measure it to a trillionth of a second and that's how they know the moon is moving away from us.

I thought the same thing about the moon being a couple of meters further away if I hit 100! Great minds honey pie :o)

[Lakitu]

I don't know, I'm just taking what the scientists say at face value LOL

[joggerjayne]

Maybe the reflector has just sunk 3cm into the soft Moon dust ...

Causing everyone to think ...

"The Moon's moved away 3cm!!"

Heeeeelllp !!

[Lakitu]

LOL!! Maybe, but I doubt it, apparently after the big bang, the moon was only 15,000 miles from us and Earth was spinning fatsre than what it is now and the seas were mental.

If they know stuff like that, then I'm pretty sure they'll know the reflector hasn't sunk.

(Can it sink with zero gravity anyway?)

[tigerlily11]

Boy even the naighbors want to get away from this train wreck called earth.

[Lakitu]

lol!

[joggerjayne]

It's not zero gravity, it's about one sixth of our gravity.

Surely you can't dump a big mirror on the Moon and hope that, after 39 years, it hasn't even moved 3cm ???

[tigerlily11]

But the marine life would suffer heavily for it. Turtle, for instance use the cycle of the moon for laying eggs and so on.
Of course there would be no tides. But I'm not sure how else this would affect us.
I think I would miss it in the night sky, but then I won't be here when it happens.
Unless the moon station they are planning goes awry and gets all Space 1999 on us.

[naomi24]

I love Jayne's explanation. :o)

[Lakitu]

LOL! You have a good point, let's see if there's anyone out there than can answer these questions :o)

[joggerjayne]

This Moon stuff just doesn't hang together.

The explanations about little mirrors all sound highly implausible.

Here comes Skeptical Cat !!! ...

http://www.jdray.net/photos/d/2812-4/skeptical _cat.jpg

... who is fraught with skepticism.

[Lakitu]

Hang on though, it hasn't just moved 3cm, it's moved 3cm every year since they started measuring the distance, which is around the time Neil and Buzz put the reflectors on in '69 (quick calculation commences), so they're saying it's move 117 cm away from us since then.....?

I remember Sir Richard talking about the turtles using the moon cycles to lay their eggs, Tiger :o)

Do you think the rest of the marine life would die eithout the tides? Don't the tides bring nutritious things with it for the fish?

[dundurn]

It will take a long time for the tides caused by the moon to disappear. Slowly enough for at least some of the organisms affected by it to get used to the changes. But the tides won't disappear completely because the Sun also causes tides. The highest (spring) tides are cause by the Sun and the Moon operating together (when the Sun, Earth, Moon fall in a straight line - full moon and new moon). The lowest (neap) tides are caused when the Moon-Earth axis is at right angles to the Sun-Earth axis (Half-moon, waxing or waning, makes no difference).

[Lakitu]

So if we didn't have the moon, we'd still cope?

[ChuckFickens]

strangely it's the tidal movements that are causing the moons orbit to increase, it's kinda a gravitational friction between the tides and the moon that tries to push the moon further forwards in it's orbit and at the same time making the orbit slightly larger.

The increase won't go on for ever though, there will come a time (eventually, if the earth is still in existence ) when the increase will stop with the orbit being about 1.6times what it is now.

as for the tides, even if the moon ceased to exist right now we would still have tides that would be caused only by the gravitational pull of the sun, but they would be about a third of the size we get at the moment.

However if the moon had never existed at all it would be a totally different story, in the same way that the gravitational friction is pushing the moon forward in its orbit it also slows the earths rotation down a tiny bit, if there had never been a moon we would have days that would only last about 6 hours which would have very extensive effects on life on earth.

[Lakitu]

Excellent! I'll stop worrying about it now, thank you :o)