What about the ROLE of the MOON?


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Rick A. Buchan
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Message 1055585 - Posted: 13 Dec 2010, 5:45:55 UTC

I was 10 when we landed on the Moon and therefor was
always fascinated by the idea of space travel.(Apollo 11 actually launched on my birthday July 16th, 1969)

Also, my generation was captivated and motivated by the first exploratory efforts of Carl Sagan and The Pioneer project. My teenage friends and myself would have fun discussing what life might be like and would ET be hostile, friendly, or indifferent etc. It seemed to be a no brainer that other life HAD to exist given all the galaxies with stars etc.

To a degree I still believe that and am happy to have SETI running on my computer to do MY tiny part of a HUGE project but.....

Recently I watched a documentary that really shook my belief in the inevitability of ET.

The documentary is called "If We Had No Moon." It was made in 1999. In this a new theory was presented about the creation of the Moon and some other revelations that I think need to be factored into the
Drake equation.

I would like to summarize the main points presented
and would love to get some informed feed back.

1. We are PART of the Earth-Moon system.Intricately connected NOT an Island unto ourselves.

2. OUR Moon is unique in the Solar System in that it is huge relative to the size of the Parent Planet.

3. The Earth was struck by a planet 1/2 the Earth's diameter in a very oblique angle, sort of deflected and impacted a 2nd time. The debris was ejected just past the Roche radius and soon formed the Moon.

4. This theory developed by Dr.Robin M. Canup has not only received serious attention but has become the most recent accepted idea of Moon formation.

5. Life on the Earth is UTTERLY DEPENDANT upon the Moon for several reasons, most important of which is it's stabilizing effect on the Earth's tilt.

6. The chaotic aftermath on the Earth right after impact...Tsunami tidal action, wild volcanic activity, probably had a lot to do with cooking and stirring the primordial soup to get life started in the first place as well as creating the elusive "reducing atmosphere".

IF this IS really how the Moon was formed, I find it highly unlikely to be duplicated. Robin Canup calls our situation of having a "lucky Moon" around the perfect planet around the perfect sun "fortuitous". I would call it a miraculous fluke.

Dr. Canup sums up the documentary with a profound question..in the search for other habitable planets,maybe more important than asking how likely are other Earths, but maybe how likely are we to find other MOONS?





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Message 1055614 - Posted: 13 Dec 2010, 11:31:45 UTC - in response to Message 1055585.
Last modified: 13 Dec 2010, 11:32:17 UTC

[...]

IF this IS really how the Moon was formed, I find it highly unlikely to be duplicated. Robin Canup calls our situation of having a "lucky Moon" around the perfect planet around the perfect sun "fortuitous". I would call it a miraculous fluke.

Dr. Canup sums up the documentary with a profound question..in the search for other habitable planets,maybe more important than asking how likely are other Earths, but maybe how likely are we to find other MOONS?


True enough if you are looking for other humans and another 'Earth'.

However...

Do not underestimate the vastness of space, and the vastness of time, and from that the opportunities for other life to develop under various conditions. In amongst that vastness, there may well be another Earth, somewhere, somewhen.


Considering how evolution builds in ever greater complexity, I think there is a very good chance for intelligent life to exist elsewhere in the space and time of our universe.

Meanwhile, we are just an ephemeral blink in the time of our universe...


Keep searchin',
Martin
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Message 1055665 - Posted: 13 Dec 2010, 16:59:22 UTC

The Moon is very helpful to life on Earth, no doubt. As you say, the variations in Earth's axial tilt would be much greater without its influence. These might occur slowly enough to allow life to develop and evolve into complex forms; this isn't really clear. Various calculations have apparently given conflicting answers. This is a very subtle and complex problem, involving the influences of the Sun, Venus, Mars, and Jupiter. There is no practical solution, only approximations. Even if a large moon is necessary for the emergence of advanced forms of life, it isn't clear that, given billions of years, this wouldn't happen in many other solar systems. In our own system we have two examples of 'binary worlds'. Besides Earth and Moon, there is the case of Pluto and Charon. Their diameters, respectively, 1413 miles and 728 miles. A 2:1 ratio, even more notable than the Earth to Moon 4:1 size ratio. There are other situations where life might take hold on an axially stable bodies. Earth-sized moons in orbit of a super-jovian planets, and tidally locked planets of M class stars spring to mind. Michael

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Message 1055708 - Posted: 13 Dec 2010, 19:25:10 UTC - in response to Message 1055665.

Thank you so much for your reply to my post! This is such great fun to discuss.

Let me clearly say that I am not a naysayer. I still think that it is (almost) unthinkable that we are alone given the incomprehensible vastness of the Universe. My mind is not made up and I doubt it will ever be.

When this idea was first really became popular and we finally had the technology to actually make some kind of attempt to do something there where 2 main factors that made the case for ET an almost slam dunk affair for me.

1. Nothing in science happens only once. Given similar conditions what happens here happens elsewhere. Natural processes can't help occurring.

2. The Drake Equation

The Drake Equation makes it all a numbers game so that even if you assign even small values to some of the variables you still wind up with a fairly large number of intelligent civilizations. I'm sure most of us has played that game and found it fun and convincing. I don't think it is at all invalid but it is misleading for the ET results that mean something to me.

The formation of stars,planets,and solar systems happens through natural, often repeating processes and the Drake equation is fine for this part of the question. If moon formation was a simple "natural" matter then I would have no problem with the original number game argument.

I'm not saying the formation of our Moon was supernatural - just so fluky I just can't see it being repeated with anywhere near the frequency as being formed out of a process similar to planet formation.

So the situation becomes;

how many stars like our sun have planets? How many have planetary systems? How many of those have a planet like Earth? How many of those are in the habitable zone? How many of those have had a collision with a body of sufficient mass at just the right angle and velocity to eject enough matter above the Roche Radius to form a moon with a mass of x ....

The value of that number may not be zero but its got to be pretty darn tiny. Again though that is for an Earth based version of ET. You brought up some interesting points about maybe a stable planet without a moon and maybe a body big enough to do the job might be possible without an impact formed moon.

I thought your idea about an Earth that WAS a moon was a great idea! If I'm so smart why didn't I think of that!? LOLOL







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Message 1055711 - Posted: 13 Dec 2010, 19:33:16 UTC - in response to Message 1055708.

moons are not unusual, even within the solar system.
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Message 1055713 - Posted: 13 Dec 2010, 19:36:26 UTC - in response to Message 1055585.

For anyone interested I just checked and the video I mentioned is available on Youtube here is the link http://www.youtube.com/watch?v=cLajKFij8xI[/url]

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Message 1055773 - Posted: 14 Dec 2010, 0:58:46 UTC - in response to Message 1055713.

Rick, thanks for sharing that video. I just viewed it. Quite good, overall. It dismisses the significance of the Pluto/Charon pairing without really explaining the reasons for doing so. The Moon is referred to as a world in its own rite, yet Pluto, which is 2/3 as large as the Moon is called an insignificant planetoid. The fact that there are already two known instances of substantial bodies with large moons in our solar system, with the Trans-Neptunian objects just beginning to be studied, seems considerable. If it can happen twice in one solar system, it may not really be so very uncommon in other systems. Michael

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Message 1055774 - Posted: 14 Dec 2010, 1:16:42 UTC

Our Moon will, at some point leave orbit and fly off into space. I can't remember if it is before or after the sun swells into a red giant and engulfs the Earth. Anyway, the Earth will begin to change the rythmic action it sees now, and wobble a bit. That would definitly affect anything we would consider normal. Different planets were formed in sililar, and very different ways to Earth, and their spin, axis angle, and mass depends on exactly how they were formed. Many are stable without the presence of a moon, while others require their lunar systems, but could could have vastly different patterns than we are used to. There have to be many, different conditions that would support life. Physics and biology at their best.

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Rick A. Buchan
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Message 1055794 - Posted: 14 Dec 2010, 3:23:55 UTC - in response to Message 1055774.

The Moon is retreating from Earth and has been since it formed. From an initial distance from Earth of 14,000 miles to around 230,000 miles now. Currently it is moving away from us at the rate of 1.5 inches/year.
So I think the Moon & Earth will have pretty much parted ways by the time the Sun runs out of gas. Than you for taking the time for replying and sharing your thoughts.

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Message 1055806 - Posted: 14 Dec 2010, 3:55:34 UTC - in response to Message 1055773.

Michael - I'm so glad you watched the video. The only reason I can see for dismissing Pluto is since it is so far from the habitable zone. But yes you are right they did sorta try and sweep that under the carpet.

In one of my posts I mentioned about ET results that matter to ME. To expand on that a bit... Although ANY life that may be found would be huge and interesting on a certain level, I personally would not jump for joy at finding some microbes floating around an ocean under 100 feet of ice on one of Jupiter's moons.

When we find some cross chatter that makes someones' screen saver go nuts is when I break out the bubbly! Of course, being Canadian, it would be more like Ice cold Pilsner but you get the idea...

I think if SETI @ Home is successful what we would pick up would be incidental communication as opposed to a "message". Aside from launching Voyager with a "ET or Current Resident" msg inside, I don't think WE have sent out any message ourselves. I could be wrong about that though. ( I have been wrong before...1974 I think it was...)LOLOL

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Message 1055980 - Posted: 14 Dec 2010, 16:44:02 UTC - in response to Message 1055806.

Rick; Seriously doubt that Pluto has life of any kind, even considering its axis-stabilizing moon. An interesting planet/moon system, though. Charon's orbit is even more circular than that of our own Moon, which argues against its having been captured by Pluto. It might have formed in place, or perhaps Pluto had a glancing blow from another object, just as Earth appears to have had, creating Charon in the process. Yes, news of intelligent life in space would be more exciting than that of ET microbes. I wonder sometimes if it is hoped in certain quarters that we first find the microbes, as a sort of preparation for the momentous news of intelligent life. Intentional messages have been sent into space several times. They did this at Arecibo in 1974. NASA did so more recently, and there have been several sent from the Evpatoria radio observatory in Ukraine. Michael

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Message 1056361 - Posted: 15 Dec 2010, 19:09:21 UTC

I always love the debate..everybody prefers to kind of ignore the fact that there's really no data...guess what you want it's as good as anybody elses.
All we have to go on is observed data from earth's biosphere and one point does not make a line....or maybe when all you know about is a hammer it looks like there should be a hell of a lot of nails around.
At this point it's a faith based, not a science based debate.
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Message 1056371 - Posted: 15 Dec 2010, 19:49:43 UTC - in response to Message 1056361.

I understand what you're saying about 'no data'. All our thoughts on these matters are, of course, speculations. I disagree, though, about this not being scientifically-based speculation. We may have only one data point (Earth) so far, but we also have the longstanding, and so far correct principle of 'non-uniqueness of viewpoint.' Every time humans have thought themselves uniquely placed in the universe, later knowledge has proved us wrong. We once thought ourselves at the center of the entire universe. Later, at the center of this solar system. Still later, at the center of the galaxy. All wrong, of course. When thinking about life in the universe, there has sometimes been a similar tendency to think ourselves unique. If we are not uniquely placed, on what basis can we assume that we are uniquely alive, or uniquely (somewhat) intelligent? What little we know of the universe points to the likelihood of a multitude of life-favorable environments. Speculation? Yes. Unscientific? No. It was Dr. Albert Einstein who said 'imagination is more important than knowledge'. Michael

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Message 1056432 - Posted: 15 Dec 2010, 22:23:47 UTC - in response to Message 1056371.

Hebrews 11:1 (King James Version
"Now faith is the substance of things hoped for, the evidence of things not seen."

This thought crossed my mind the other day. In a loose sense I agree. Those of us actively involved believe what has yet to be demonstrated.
But for ME, at least, it's more a belief in the Great Idea that ET exists and that the search will eventually bear fruit.
Having "faith" in the idea enough to engage in the debate and DO something to test the theory and keeping an open mind and accepting the possibility that we may never find Extra Terrestrial Intelligent Life or that it may indeed not exist at all and that we may, in fact, be alone.

The difference,I think, is with religion, faith and acceptance is the end of it, with science it is only the beginning (of the quest).

Further to that in response to the other posts I have read ie "If ET exists why have we not discovered it?" or "SETI is not doing it right etc..."
Science is based on having an idea trying it, testing it and making adjustments to find the truth.
I am not a scientist and I'm sure a lot of people a lot smarter than me have thought long and hard about what we can do and how to start. Maybe there are things that we can do different or other approaches and I have no doubt the search will be "fine tuned"(Pun intended :D) as required.

Incidentally, I would love to see a full featured video of the evolution the the SETI program. It would be great to see the pioneering faces behind it all discussing exactly how goals where chosen, what assumptions where made, and how decisions where made as to approach to take for detection etc also what would happen in the event a message was discovered. Not just regarding the breaking of the story, but trying to decipher the message itself.

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