No Moon, no life on Earth, suggests theory

NewScientist.com ^ | 18 March, 2004

[RightWhale]

It might be that the constantly changing conditions caused by tides would force lifeforms to higher behavior. Earth's rotation would provide this even without the moon, but the cycle would be simple. It's one thing to grow in a Petri dish, but another to be out in cyclical conditions. There is the daily sun cycle and the seasonal cycle, but adding the moon as another harmonic would complicate the enviroment. The complex cycles would force complex adaptation.

[balrog666]

Without the Moon, life may be far different that what we have today.

I want a Moon!

[jennyp]

could

what speculative drivel. Does someone get paid to write this nonsense?

Yeah, who do these people think they are coming up with hypotheses - scientists?

And what makes these so-called scientists think they can get away with making anything less than categorical assertions of god-like certainty? Anything less than WWF-like bravado is the same as total capitulation to all alternate theories. Science has NEVER made progress by making tentative, qualified statements.

[Dimensio]

Abiogenesis is impossible...and that has been demonstrated over and over again.

I must have missed this. Could you provide a reference to where it was demonstrated that abiogenesis is completely impossible?

[farmer18th]

Yeah, who do these people think they are coming up with hypotheses - scientists?

Doubt it. Scientists have at least some remote chance of observing phenomena.

[Junior]

It's a common human failing to be suspicious of those more -in-the-know than you are. Hence, folks who have absolutely no clue as to what they are talking about will make broad-brush condemnations of actual research in the field, because "them there pointed headed int-uh-lectules can't possibly know what they is talkin' 'bout."

[edwin hubble]

"If you look at the Earth's tilt in reference to the ecliptic plane, the Moon seems to have played a large part in keeping it stable. "

Hello, RadioAstronomer. I was aware of the mechanics of lunar orbit and the effect of the moon on the stability of Earth's axis over time.

Are you aware of any evidence of a long-term process of axis tilt (tumbling) by Mars or Venus?

---
Also, I can certainly see that stronger tides in earlier eras might have affected shoreline environments in coastal waters (early life in the inter-tidal zones).

The implications are obvious for Weak Anthropic Principle: human-like life would be even more rare.

and it would mean a much lower value of the Drake Equation variables Ne and Fl: a lower probability of extraterrestrial life.

[Ne: For each star that does have a planetary system, how many planets are capable of sustaining life?

[Fl: On what percentage of the planets that are capable of sustaining life does life actually evolve? ]

--
Also...
Tectonic Plate activity, (complex in origin and apparently unique in the solar system) likewise has been cited by others as necessary-for-longterm-life on Earth.

[longshadow]

rare placemarker

[RadioAstronomer]

Are you aware of any evidence of a long-term process of axis tilt (tumbling) by Mars or Venus?

From here:

http://www.astronomy.com/Content/Dynamic/Articles/000/000/001/611spati.asp

"While Earth’s axial tilt has only varied between 22 to 24.5 degrees in the past 10 million years, Mars has experienced a more extreme wobble, ranging from 14 to 48 degrees."

Another interesting read:

http://www.rps.psu.edu/jan97/planets.html

"The obliquity of a planet is the angle of its spin axis -- that imaginary rod that skewers a planet through the poles -- in relation to the plane of its orbit. In Earth's case, this angle is a modest -- and reasonably steady -- 23.5 degrees, enough of a tilt to account for our seasons. Because of Earth's obliquity, in the northern hemisphere the winter sun stays low in the sky, casting its rays obliquely across the landscape. In summer it climbs to more nearly overhead, an angle much better for warming."

---snip---

"Mars, Laskar showed, still does, its obliquity varying chaotically between 0 and 60 [Note: I did notice there was a difference in the numbers] degrees. The only thing that saved Earth from a fate worse than Mars', he says, was hooking up with the moon.

A little orbital mechanics may be in order here. Earth is a body in complex motion. It rotates, of course, once every 24 hours. At the same time, on a different time scale, it revolves around the sun. But there are other, subtler, motions which must also be accounted for. Earth's imperfection as a sphere, for one thing, adds a motion called precession, akin to the wobbling of a spinning top. Earth wobbles, as noted above, only slightly and in very slow motion, its obliquity oscillating from 22 to 24 degrees every 40,000 years.

Meanwhile, however, the gravitational pull of the other planets in the solar system, especially the giants Jupiter and Saturn, causes a different kind of precession: a wobble in the plane of Earth's orbit. Imagine the orbital plane as a solid object, a spinning frisbee or a dinner plate, with the sun a dollop of mashed potatoes in its center, and Earth a wad of chewing gum stuck to its outer rim. The insistent tug of these outer, larger planets against the sun's stronger pull causes the plate to wobble as it spins.

The real action, in terms of shifting obliquity, comes when these two types of wobble -- the planetary and the planar -- stumble onto the same frequency. Then you get what's known as a spin-orbit resonance: in synch, the two motions combine their energy, creating a much larger force. It's not unlike the kind of timing it takes to keep a hula-hoop spinning around your hips, or to successfully push a child's swing. For a planet, however, resonance means chaos, as two small competing wobbles become one huge concerted one.

What saves Earth from falling into a spin-orbit resonance, Laskar says, is the moon. Because of its size and proximity, the moon exerts a strong gravitational pull of its own on our home planet -- a pull which turns out to be a stabilizing influence. The lunar effect acts to accelerate Earth's global precession, maintaining it at a steady frequency well higher than the torpid wobbling of the orbital plane. Take the moon away, Laskar says, and keep things otherwise the same -- give Earth the same mass, orbital position, rotation rate, etc. -- and Earth's obliquity would fluctuate between 0 and 85 degrees."

and it would mean a much lower value of the Drake Equation variables Ne and Fl: a lower probability of extraterrestrial life.

That I am not sure of. Life may be just as likely, but adapted to those environments. I just dont know. Life sure seems to be able to live in the extremes on this planet.

[LiteKeeper]

You can't be serious! Oh well, first shot, check the research of Louis Pasteur

More later - I am just passing though at the moment

[LiteKeeper]

Life from life...or not?

[Guvmint_Cheese]

I think this is a more accurate explanation of the moon's importance for life on Earth:

http://www.rathergood.com/moon_song/

[edwin hubble]

That is one of the most chilling and unnerving presentations I have seen in a long time. LOL.

[PatrickHenry]

Oh well, first shot, check the research of Louis Pasteur

BWAAAHAHAHAHAHAHAHAHAHAH!

[Dimensio]

Oh well, first shot, check the research of Louis Pasteur

I'm aware of the research of Louis Pasteur. He did not disprove abiogenesis, he merely disproved spontaneous generation: the idea that maggots spontaneously appeared in rotting meat.

[mhking]

Without the Moon, there would have been no life on Earth.

Yep. No place for the Justice League's Watchtower to keep us all safe.

[Ichneumon]

I'm aware of the research of Louis Pasteur. He did not disprove abiogenesis, he merely disproved spontaneous generation: the idea that maggots spontaneously appeared in rotting meat.

Hey, that's close enough to "abiogenesis of primitive autocatalysis has been disproven completely, end of story" for creationist work.

[js1138]

I have been watching creationists cite Pasteur for several years now, and it suddenly occurs to me that pre-scientific Christians must have believed in abiogenesis.

[longshadow]

Pasteurized placemarker (maggots will not spontaneously appear from this placemarker)