sunset from behind the wire

sunset from behind the wire

Saturday, April 2, 2016

Thank You Moon

Credible speculation as to Earth's ability to sustain life and a stable environment (despite the plague of global warming that currently alarms the progressive community) includes the presence of Jupiter and Saturn in the outer Solar System sweeping up many of the comets that could otherwise take out all life on our home. More recently, the presence of the Moon is credited as another key to life as we know it.

The Earth's magnetic field permanently protects us from the charged particles and radiation that originate in the Sun. This shield is produced by the geodynamo, the rapid motion of huge quantities of liquid iron alloy in the Earth's outer core. To maintain this magnetic field until the present day, the classical model required the Earth's core to have cooled by around 3,000 °C over the past 4.3 billion years. Now, a team of researchers from CNRS and Universit√© Blaise Pascal suggests that, on the contrary, its temperature has fallen by only 300 °C. The action of the Moon, overlooked until now, is thought to have compensated for this difference and kept the geodynamo active. 
Denis Andrault, Julien Monteux, Michael Le Bars, Henri Samuel. The deep Earth may not be cooling down. Earth and Planetary Science Letters, 2016; DOI: 10.1016/j.epsl.2016.03.020
The classical model of the formation of Earth's magnetic field raised a major paradox. For the geodynamo to work, the Earth would have had to be totally molten four billion years ago, and its core would have had to slowly cool from around 6800 °C at that time to 3800 °C today. However, recent modeling of the early evolution of the internal temperature of the planet, together with geochemical studies of the composition of the oldest carbonatites and basalts, do not support such cooling. With such high temperatures being ruled out, the researchers propose another source of energy in their study.

The Earth has a slightly flattened shape and rotates about an inclined axis that wobbles around the poles. Its mantle deforms elastically due to tidal effects caused by the Moon. The researchers show that this effect could continuously stimulate the motion of the liquid iron alloy making up the outer core, and in return generate Earth's magnetic field. The Earth continuously receives 3,700 billion watts of power through the transfer of the gravitational and rotational energy of the Earth-Moon-Sun system, and over 1,000 billion watts is thought to be available to bring about this type of motion in the outer core. This energy is enough to generate the Earth's magnetic field, which together with the Moon, resolves the major paradox in the classical theory. The effect of gravitational forces on a planet's magnetic field has already been well documented for two of Jupiter's moons, Io and Europa, and for a number of exoplanets.

Since neither the Earth's rotation around its axis, nor the direction of its axis, nor the Moon's orbit are perfectly regular, their combined effect on motion in the core is unstable and can cause fluctuations in the geodynamo. This process could account for certain heat pulses in the outer core and at its boundary with the Earth's mantle.

Over the course of time, this may have led to peaks in deep mantle melting and possibly to major volcanic events at the Earth's surface. This new model shows that the Moon's effect on the Earth goes well beyond merely causing tides.

Life exists on the Third Rock due to a very complex set of circumstances. 



17 comments:

  1. Sometimes the moon helps get you laid... a more important aspect of its features.

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    1. ...and there are the cycles that make it less likely that you'll be laid.

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  2. Very interesting,
    the more we think we know the more we find to know...

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    1. So it seems. I'm glad that it's that way.

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  3. Spirit of the Moon. Some experts think the moon's hollow and an artificial construct. Others speculate that it hides the small but adventurous Anglican Church of Canada.

    I'm not saying that these theories are true, but I'm not saying they aren't, either.

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  4. Global warming is going to get you, Denier.

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    1. If Barack had his way, we'd be prosecuted for denying.

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  5. Replies
    1. And the fact that we're at the right distance from the Sun so most of that water stays liquid.....

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  6. Once upon a time, in a land far away . . .

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    1. Long ago in a galaxy far away there were Star Wars.

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  7. there's more to moon than what meets the eye.
    from those tides to saving us, sooner it'll also see human settlements I guess (given the pace at which we're moving).
    I read about a triple star system found by Astrophysicists at Harvard. 'guess by 2021 when the new telescope (which is bigger than Hubble) will show up, we'll be questioning all the knowledge we've had so far about space!

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  8. All true. And we may end up leaving the cradle for the stars.

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  9. We don't give enough credit to those highly potent forces that seem to be necessary for higher life forms to develop. There's a metaphor in there somewhere about how difficulties help shape good humans.

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    1. The elements that would seem to need to be present for life as we know it to flourish are somewhat specific. We haven't found other life in our corner of the galaxy and we can only opine that the "engineering" necessary for that to happen has not been present.

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