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Article: Earth's Stabilizing Moon May Be Unique Within Universe - Comments

SaganTheCat's Avatar Comment 1 by SaganTheCat

tide comes in, tide goes out...

Fri, 29 Jul 2011 16:20:56 UTC | #855597

Cook@Tahiti's Avatar Comment 2 by Cook@Tahiti

Simulations also showed that gas giants don't form in the inner solar system.... until we looked at other solar systems.

Fri, 29 Jul 2011 16:21:50 UTC | #855600

aquilacane's Avatar Comment 3 by aquilacane

Research reveals that less than 10 percent of terrestrial planets may have a satellite large enough to provide the stability life needs to develop.

...to provide the stability life would need to develop as it did on earth.

Such shifts have the potential to impact the development of life.

...on earth but would be perfectly suitable for life that evolved there.

How much of the formation of life is dependent on a larger-than-normal moon is still a matter of debate.

...is completely unknowable without another life bearing planet to study.

Fri, 29 Jul 2011 16:22:04 UTC | #855601

neil pharr's Avatar Comment 4 by neil pharr

"unique with the Universe" - maybe "very rare" would be a better use of words. This is Science. PS don't forget the Prout google.

Fri, 29 Jul 2011 16:30:07 UTC | #855604

Jos Gibbons's Avatar Comment 5 by Jos Gibbons

"15 out of 180", or "1 in 12", is not so much "unique in the universe" as "likely to happen as much as once per stellar system". I mean, that's about 22 orders of magnitude from "unique".

Fri, 29 Jul 2011 16:35:31 UTC | #855607

Billions and Billions's Avatar Comment 6 by Billions and Billions

The problem I have with this article is that it misleads the reader into thinking that life is unique to earth. Yes, a moon formed via a collision is not as common, but that should not imply that life of some form cannot develop on a planet having a smaller moon or none at all.

I also have a problem with this statement: "The moon has long been recognized as a significant stabilizer of Earth's orbital axis. Without it, astronomers have predicted that Earth's tilt could vary as much as 85 degrees. In such a scenario, the sun would swing from being directly over the equator to directly over the poles over the course of a few million years, a change which could result in dramatic climatic shifts. Such shifts have the potential to impact the development of life."

A few million years is plenty of time for life to migrate as the Earth's axis shifts.

Also, since when is 8% (the simulation results) considered "unique"?

This is the kind of article that creationists will latch on to and proclaim "proof" that our existence is not a mater of chance.

Fri, 29 Jul 2011 16:50:23 UTC | #855610

huzonfurst's Avatar Comment 7 by huzonfurst

Agreed, very sloppy and unscientific statements in this article.

Fri, 29 Jul 2011 17:00:18 UTC | #855614

-TheCodeCrack-'s Avatar Comment 8 by -TheCodeCrack-

The article makes sense, though.

Effectively, for life to evolve, it needs time to adapt. Abrupt & massive changes in the environment would be detrimental to life evolving to things like very big complex animals: like us.

Anything that keeps the environment relatively stable should lessen the chances of extinction.

Just imagine a species trying to survive if the planet was really random.

Fri, 29 Jul 2011 17:15:47 UTC | #855616

KenChimp's Avatar Comment 9 by KenChimp

Pseudo-scientific, apologist, ignorance enabling prattle.

There is little evidence to suggest that the earth's axis would tilt as much as 85 degrees without the gravitational influence of the moon. We don't see the Martian poles undergoing that extreme. In fact, Mars' axial tilt is nearly the same as that of the earth's. It's two tiny moons are probably captured asteroids and contribute nada to stabilizing Mars' axial tilt.

Venus's axial tilt is very odd, the planet is nearly upside down compared to the axes of the other planets in the solar system, but this may be due to massive impact early in its history, or due to tidal influences from its closer position relative to the Sun. So why is there the suggestion that the earth without this moon would have wild axial eccentricity?

What eccentricity we do see causing the Earth's precession may be directly due to its collision with whatever planetary body produced the moon, and the theory that earth would experience a wilder precession due to gravitational effects of the other planets without its "guardian moon" are not well evidenced.

Fri, 29 Jul 2011 17:17:50 UTC | #855617

Sara12's Avatar Comment 10 by Sara12

Comment 3 by aquilacane :

Research reveals that less than 10 percent of terrestrial planets may have a satellite large enough to provide the stability life needs to develop.

...to provide the stability life would need to develop as it did on earth.

Such shifts have the potential to impact the development of life.

...on earth but would be perfectly suitable for life that evolved there.

How much of the formation of life is dependent on a larger-than-normal moon is still a matter of debate.

...is completely unknowable without another life bearing planet to study.

A sample set of one never got anyone very far...

Fri, 29 Jul 2011 17:19:21 UTC | #855618

Sensible's Avatar Comment 11 by Sensible

Victor Stenger’s latest book “The Fallacy of Fine Tuning” debunks all the theories proposed by religious wingnuts, (Francis Collins included) that many of the Universe’s physical parameters are so ‘fine-tuned’ that it can only have been designed by an intelligent creator. They claim that with only the slightest variation in any one or all of these parameters would have resulted in life being impossible. Thus, the reasoning goes, god exists. This latest revelation that the moon is ‘unique’ to our planet, which it is not, is pointed out by Comment #6 OccamsRazor as only 8% unique. This should be enough to debunk any further bullshit from religious ignoranus’s. Unfortunately though, it will assuredly bring a new flurry of activity from the religious wingnuts with unsubstantiated comments like, “See?, here is even more proof for you dumb atheists”. I think the orbiting teapot is the reason for the possibility of life. (tongue-in-cheek)

Ignoranus – One who is not only stupid, but also an asshole.

Fri, 29 Jul 2011 17:38:02 UTC | #855620

AtheistButt's Avatar Comment 12 by AtheistButt

similar comparisons to the moons of Venus and Mars

Some commenters on the site seem to think this proves she doesn't know what she's talking about. Venus has no moon.

Fri, 29 Jul 2011 17:55:09 UTC | #855625

All About Meme's Avatar Comment 13 by All About Meme

Ergo Jesus?

No. If anything, this article suggests we should return to Moon worship.

Please bow your heads and join me in a prayer to Artemis.

Fri, 29 Jul 2011 18:04:03 UTC | #855629

justinesaracen's Avatar Comment 14 by justinesaracen

Nola Taylor Redd has pretty shaky credentials for a science writer. Her university background is creative writing! If you Google her, the first entry is her Facebook page, and she appears to have no published scientific papers in astronomy. Explains why she would assert that Venus has a moon. I would say her scientific credibility is less than a dozen or so people who post here at RD.com. She sounds dangerously close to an IDer, or at least someone who is willing to pave the way.

Fri, 29 Jul 2011 18:16:10 UTC | #855631

Universeman's Avatar Comment 15 by Universeman

Research reveals that less than 10 percent of terrestrial planets may have a satellite large enough to provide the stability life needs to develop.

Wouldn’t a figure like that make a moon like ours relatively common place in the universe. If 1 out of every 10 terrestrial planets in the universe has a moon like ours, that really adds up quick.

Fri, 29 Jul 2011 18:31:41 UTC | #855633

ZenDruid's Avatar Comment 16 by ZenDruid

Thank you for researching that, esuther.

I agree with everything said thus far, except #13. Life and everything would not exist without the glorious and beneficent Ra, Who prefers that we worship Him skyclad.

Fri, 29 Jul 2011 18:35:34 UTC | #855634

glenister_m's Avatar Comment 17 by glenister_m

Judging by the comments on the main site, most of the readers see through the shoddy science/conclusions the article presents.

Considering the mass extinction events that life has survived on this planet (not to mention the "Snowball Earth" hypothesis), once life gets established on another planet, even one with large climactic shifts, it will adapt to survive them.

Another good question is how many planets would have the right amount of water (enough for life to develop, but not too much so that the entire surface is covered)? If an intelligent species evolved on a completely ocean-covered planet, how far could it develop technologically?

Fri, 29 Jul 2011 18:38:25 UTC | #855637

Naturalist1's Avatar Comment 18 by Naturalist1

Has anyone else taken a look at the rest of that website?...space.com. There is an awful lot of jesus stuff on it. Didn't increase my opinion of it's credibility.

Fri, 29 Jul 2011 18:46:21 UTC | #855639

AtheistButt's Avatar Comment 19 by AtheistButt

Comments by Esuther and Naturalist1 prompted me to take a look at her Facebook page - take a look at her profile pictures - no 6.

Fri, 29 Jul 2011 19:02:31 UTC | #855642

KenChimp's Avatar Comment 20 by KenChimp

Comment 12 by AtheistButt :

similar comparisons to the moons of Venus and Mars

Some commenters on the site seem to think this proves she doesn't know what she's talking about. Venus has no moon.

Venus has no moon and its axial tilt is 177 degrees != Venus has no moon ergo its axial tilt is 177 degrees. We don't know why Venus is "upside down" compared to the other planets and their axes. We don't really know why earth's axial tilt is 23.5 degrees with a 1% eccentricity. It is, admittedly possible that the moon's gravitational influence did help stabilize the earth's axis after whatever impact event extruded the moon from earth. But in the absence of that impact event there would be no moon and, more likely than not, no need for such "stabilization".

Mars may as well have no moon (its tiny moons have negligible impact on the tilt and eccentricity of its axis), and its axial tilt is very similar to earth's.

Yes, in the extent of her statements suggesting that if the earth had no moon its axial tilt could be as much as 85 degrees, she doesn't know what she is talking about. Could be? Sure. Would be? Probably not. In fact, there is a better chance that eccentricity of earth's axial tilt would be smaller than is now (it is just under 1%) if the event which caused the moon to be extruded from the earth never happened.

The author is engaging in speculation in such a manner as to lend that speculation greater credence than the relatively paltry body of evidence we have for even engaging in such speculation can reasonably accommodate. It is pseudo-scientific at best, and I have a sneaking suspicion it is ID-apologist in the form of yet another ridiculous "fine tuning" argument for earth.

Fri, 29 Jul 2011 19:34:10 UTC | #855646

Cartomancer's Avatar Comment 21 by Cartomancer

Well, the title is technically correct. The earth's moon may be a unique phenomenon in the universe, and we can't say it isn't until we find another one. But then again, by the same logic, I might be the sole custodian of every last grapefruit spoon on earth. I have never encountered a grapefruit spoon that is not in my possession, so until my position on this is falsified I think I shall claim to be the exclusive keeper of the world's only extant grapefruit spoon, in a feeble attempt to appear more sensational and interesting than in fact I am.

Fri, 29 Jul 2011 19:50:54 UTC | #855650

Nastika's Avatar Comment 22 by Nastika

Comment 9 by KenChimp

There is little evidence to suggest that the earth's axis would tilt as much as 85 degrees without the gravitational influence of the moon.

The figure of 85° comes from Lasker et. al's 1993 paper in Nature:

Here we investigate the stability of the Earth's orientation for all possible values of the initial obliquity [axial tilt], by integrating the equations of precession of the Earth. We find a large chaotic zone which extends from 60° to 90° in obliquity. In its present state, the Earth avoids this chaotic zone and its obliquity is essentially stable, exhibiting only small variations of +/- 1.3° around the mean value of 23.3°. But if the Moon were not present, the torque exerted on the Earth would be smaller, and the chaotic zone would then extend from nearly 0° up to about 85°

Given that ice ages can be caused by less than two degrees of axial tilt it's quite likely that even the 50° of tilt reached after a few million year's in the authors' model would have made the evolution of complex forms of life more difficult.

There is also the hypothesis that tides helped encourage the evolution of land based animals.

If would all be wonderfully fine tuned if it wasn't for that pesky G2V star that will start boiling our oceans in less than a billion years. If we're lucky we could avoid a slow roasting if the Earth gets swallowed into Andromeda's supermassive black hole in a couple of billion years.

Fri, 29 Jul 2011 20:01:41 UTC | #855654

ccr5Delta32's Avatar Comment 23 by ccr5Delta32

Think about it guys we could have a planet with dramatically changing seasons but we wouldn't have lunatics

Fri, 29 Jul 2011 20:26:53 UTC | #855659

bluebird's Avatar Comment 24 by bluebird

space.com...lot of jesus stuff on it

My fave go-to place is Spaceflight Now: link text

Fri, 29 Jul 2011 20:44:27 UTC | #855661

sanban's Avatar Comment 25 by sanban

The site is full of all manner of ignorant and otherwise unscientific woo.

http://www.space.com/12474-cowboys-aliens-real-ufos.html

Fri, 29 Jul 2011 20:55:59 UTC | #855666

Alan4discussion's Avatar Comment 26 by Alan4discussion

Comment 20 by KenChimp

Venus has no moon and its axial tilt is 177 degrees != Venus has no moon ergo its axial tilt is 177 degrees. We don't know why Venus is "upside down" compared to the other planets and their axes. We don't really know why earth's axial tilt is 23.5 degrees with a 1% eccentricity. It is, admittedly possible that the moon's gravitational influence did help stabilize the earth's axis after whatever impact event extruded the moon from earth. But in the absence of that impact event there would be no moon and, more likely than not, no need for such "stabilization".

It is my understanding that the initial planetary impact caused a debris ring which provided the material for our moon. http://en.wikipedia.org/wiki/Giant_impact_hypothesis There are various arguments listed about this of differing merits. Some counter claims look quite dubious.

Indirect evidence for this impact scenario comes from rocks collected during the Apollo Moon landings, which show oxygen isotope ratios identical to those of Earth. The highly anorthositic composition of the lunar crust, as well as the existence of KREEP-rich samples, gave rise to the idea that a large portion of the Moon was once molten, and a giant impact scenario could easily have supplied the energy needed to form such a magma ocean. Several lines of evidence show that if the Moon has an iron-rich core, it must be small. In particular, the mean density, moment of inertia, rotational signature, and magnetic induction response all suggest that the radius of the core is less than about 25% the radius of the Moon, in contrast to about 50% for most of the other terrestrial bodies. Impact conditions can be found that give rise to a Moon that formed mostly from the mantles of the Earth and impactor, with the core of the impactor accreting to the Earth, and which satisfy the angular momentum constraints of the Earth-Moon system.

There are alternative hypotheses but these lack a mechanism to account for the high angular momentum of the Earth–Moon system. The Earth's spin was so fast that there was initially a 5 or 6 hour day, with the Moon in a very low orbit. Tidal drag has gradually slowed the Earth's spin and raised the Moon's orbit to its present level. (Conservation of angular momentum) The Apollo laser reflector experiment confirms that the Moon's orbit is still rising.

There is evidence that the Moon gives the Earth axial stability and that planets without such moons wobble more giving wild changes of temperature and climate..

How Earth and the Moon interact - http://www.astronomytoday.com/astronomy/earthmoon.html

Stable Axial Tilt It is considered likely by many authors that the current circa 23.5 degree tilt of the Earth's axis of rotation is a relic of the oblique collision which produced the Moon. Furthermore it is argued that the presence of the orbiting Moon has, through a large part of geological time, stabilised this axial tilt or obliquity of the Earth. This has had important ramifications for life on the Earth as major and frequent shifts in this obliquity would have led to significant and rapid changes in the Earth's climate due to changes in insolation values at the poles and equator. A similar mechanism has been suggested to explain the apparent contradictions in the climate record of Mars.

Fri, 29 Jul 2011 20:58:18 UTC | #855669

Alan4discussion's Avatar Comment 27 by Alan4discussion

Comment 22 by Nastika

If would all be wonderfully fine tuned if it wasn't for that pesky G2V star that will start boiling our oceans in less than a billion years. If we're lucky we could avoid a slow roasting if the Earth gets swallowed into Andromeda's supermassive black hole in a couple of billion years.

The Anondromeda galaxy collision is not until 3 to 5 billion years. http://news.nationalgeographic.com/news/2007/05/070516-galaxies-collide.html

The Moon may progress into too high an orbit to continue to stabilise Earth's axis before that, but as you say the Sun may well fry the Earth first. (Space flight to the outer Solar System before then could be a good move for some)

Mind you - the political denial crowd could make the Earth uninhabitable long before that!

Fri, 29 Jul 2011 21:12:12 UTC | #855670

Anonymous's Avatar Comment 28 by Anonymous

Comment Removed by Moderator

Fri, 29 Jul 2011 21:20:40 UTC | #855674

Schrodinger's Cat's Avatar Comment 29 by Schrodinger's Cat

Oh dear. We've been here before.

I can still recall science textbooks from the 1960s, I had one as a kid, that argued the entire solar system was in some way special and unique.......as the planets must have been formed when a passing star got too close and dragged material from the sun.

Of course....we all now know that entire theory was nonsense.

The latest lunar formation idea is more of the same stuff. Scientists can't figure how the Earth-Moon system could have formed within current accretion models......so once again a 'special' event has to occur to fix the issue. Collision with some Mars sized object.

I've always been highly suspicious of the collision theory.....an event that had to occur 'just right'. It is far too much like that discredited theory for how the planets formed.

Fri, 29 Jul 2011 21:30:07 UTC | #855676

veggiemanuk's Avatar Comment 30 by veggiemanuk

Comment 8 by -TheCodeCrack- :

The article makes sense, though.

Effectively, for life to evolve, it needs time to adapt. Abrupt & massive changes in the environment would be detrimental to life evolving to things like very big complex animals: like us.

Anything that keeps the environment relatively stable should lessen the chances of extinction.

Just imagine a species trying to survive if the planet was really random.

Life would still evolve, Natural selection would just select those species whose rate of mutation could keep up with the change in climate. Just bare in mind that life cycles don't need to be the same as on Earth.

Fri, 29 Jul 2011 21:36:04 UTC | #855678