The Romance and the Science of our Moon

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original post 2008

On February 20^th many of us ventured outside into the freezing cold to witness the total lunar eclipse. Completely forgetting in that climatic moment when the earth’s shadow cast our moon into a glowing red, how cold we were, that we could barely click the shutter of our cameras because our fingers were frozen solid into a clenched fist position.

We have an incredible fascination with our moon, since the beginning of mankind this fascination had existed and rightfully so because our moon has a far greater impact on our daily lives than we’ve ever realized before.

The moon – an eighty one million billion-ton lump of rock and dust, more than 210 000 miles in diameter, orbiting almost a quarter million miles above our heads. It is the second brightest object in our skies, with temperatures ranging from 250° down to minus 380° and lower. Its gravity is a 6^th of that of earth, mountains soar to 16 000 feet and millions of craters litter the dusty dry surface where no liquid water has ever been found. This is not a hospitable place and yet, we associate the moon with romance and mystery. The man in the moon enraptures all, all over the world and feeds our hunger for supernatural myths and legends.

We are far from alone of having a moon, there are at least 135 other moons orbiting their planets in our solar system, Saturn has the most with 46. While we have at least ten mysterious bodies orbiting our planet. Five are asteroids caught temporarily by the earth’s gravitational field and four are probably remnants of the Apollo 12 rocket. The tenth and largest is our moon.

Since long before the birth of human kind the moon has been the earth’s constant companion but until relatively recently we’ve known little of its true nature or even how it was created.

There are several competing theories, one suggests that the moon is merely an asteroid orbiting our planet trapped by the earth’s gravity. Another ascribes the creation to a giant impact on our earth ejecting masses of material that formed the moon. Clues as to which theories were most likely to be correct came when men first landed on the moon and started unlocking its secrets of creation buried within the lunar rocks. Between 1969 and 1972, six missions blasted off to the moon. (Only 12 humans have ever walked on the moon).

But these astronauts did more than just rewrite history they also returned with samples of lunar rocks. These moon rocks are amazingly similar to earth rocks but they contain far less iron. This seemingly small difference offers a huge clue as to how the moon was created. It shows that …

The moon started with a bang!

Lets step back four and a half billion years in earth’s history. The moon does not yet exist, the inner solar system has a bout twice as many planets than the four that exist today. Many of them are on a crash course to destruction; among them is a planet about half the size of earth, since named Thea who in Greek Mythology was the goddess mother of the moon. The two bodies are on a collision course. Inexorably Thea rushes closer and closer towards earth, the approaching planet is a terrifying sight. It might have started looking like a star and as it got closer it would get bigger and bigger until it would have filled the sky just moments before impact and then everything would have been gone for you as a witness because everything would have been white hot and even if a friend of yours would have been standing on the other side of the earth he would have seen the white flash and feel gigantic earthquakes impacting through the earth. Thea is four thousand miles in diameter; to put its size into perspective the asteroid thought to have wiped out the dinosaurs was about six miles across. Thea is traveling at 26 000 mph, that’s about twenty times faster than a supersonic jet, so this is a gigantic event of unimaginable power. As the planets get closer, their immense gravitational fields rip each other’s layers to pieces then they catastrophically collide. The impact is equivalent to billions of megaton bombs. The impact sheers off continent size sections of the earth’s crust blasting surface rocks out into space. These surface rocks contain only a small amount of iron, the atmosphere around the molten planet is filled with rock paper; earth’s gravity pulls back most of its debris but some is catapulted into space although it cannot escape completely, instead it is trapped by the earth’s gravity forming a ring of red hot dust and rock around the planet.

In a process called accretion the circling dust and rocks collide and fuse with other fragments to create larger blocks as the debris clumps together its combined gravity becomes strong enough to attract even more debris. This chain reaction doesn’t stop until the billions of fragments of vaporized rock have gathered into one red-hot ball of matter. In less than one hundred years this cools into one lump of rock one-sixtieth the volume of earth. It becomes the moon.

When the moon forms, it is just 17 000 miles away but it doesn’t stay as close as that. Its violent birth sets it spinning away from us on a journey that will last something like ten billion years. Four billion years ago the moon orbits 86 000 miles away still three times closer to the earth than it is now. From our planet the moon would dwarf everything in the sky, during this early period of its life the moon has its most profound effects on earth.

The seasons

The massive collision that creates the moon is so powerful that it knocks the earth off balance onto an axis of 23.5°. It’s this tilt that gives us spring, summer, autumn and winter. If we spun on a vertical axis like the planet Mercury, seasons would not exist. Everywhere would receive 12 hours of day light and 12 hours of night. The poles would be entombed in an eternal freezing twilight while the equator would bake in endless heat. But the moon does more than merely produce that tilt it also maintains it. The strong gravitational pull of our young moon acts as a global gyroscope stabilizing the earth’s axis. If we had no moon we would have as the astronomers call *a chaotic obliquity* without our global stabilizer the axis could vary between 0° and 90°. This would alter the distribution of sunlight devastating our finely balanced weather system. Climate patterns would go berserk. The tropics could find themselves frozen under ice and Antarctica transform into a vast desert. But luckily the moon saves us from such disasters and allows life to exist. You might even be able to argue that life wouldn’t exist as we know it if it were not for the moon. Not all planets in our solar system are so lucky, Mars has two moons but they are too small to stabilize its tilt as a result the red planet rolls much more than our earth.

Life as we know it

The first half million years of the moon’s journey from earth has been a violent one also called the age of bombardment (asteroid impacts), over the next million years the moon continues its escape from earth and out into space. The power of its gravity creates tides over thousands of feet high, stirring up the oceans of our earth; this creates the conditions for complex chemical compounds to form. The moon is aiding the creation of life on earth. The moon created those tremendously high tides when it first formed, washing over the land for hundreds of miles taking back with it minerals to form a primordial soup and allowed life to evolve and allowed us to be here. The tides may have even helped the first DNA to take hold and evolve. Some scientists believe that the changes in chemical concentrations when the tides go in and out caused the DNA to split and replicate.

Global Climate

The moon’s influence on our tides have further vital role to play in our hearth’s history. They help the atmosphere of the whole planet to calm down and become a more hospital place in which more complex life can evolve. In our loop back to three billion years ago the earth is a very different place. The impact that creates the moon sets the earth spinning faster; it spins so much faster than it does now that a day lasts just six hours. This high-speed spin has devastating effects right around the earth. The rotation of our planet is one of the most influential factors determining global climate. This spin of the planet creates winds and vortexes in the atmosphere; the faster the spin the faster and more violent the winds. Billions of years ago when our planet turned four times faster, the atmosphere whips over the land. Imagine if we lived in that kind of a world where hurricanes like Katrina were continuous. This is the climate of our fast spinning early earth, a place with constant hurricane winds and giant ten thousand foot tides, this is too hostile for life to evolve into a more complex forms but the devastating tides that the moon is creating begin to pacify the hellish climate. (Early earth and volcano activities also known as the Hades Era). The tides affect the speeds of the rotation of our planet eventually lengthening our day from six to twenty four hours. As the earth’s rotation slows the atmosphere cease to whip around the earth. Hurricane strength winds are no longer the norm and more complex forms evolve in relative peace and calm on our planet. Without our moon life would have evolved differently, we would have evolved differently, without the moon we would be different creatures than what we are.

Over the next three billion years the moon continued its journey out into space and the moon’s influence has waned but hasn’t disappeared. Some scientists believe the moon can cause volcanic eruptions and earthquakes, some believe the moon has influence in the psychic phenomenon such as crime going up and psychiatric wards needing more attention than as a rule and other bizarre and inexplicable ways. Today the moon orbits the earth 125 000 miles away, that’s fifteen times further away from earth than when it first formed. It appears as a distant and mystical object in our night sky and its gravitational pull is far weaker than it used to be. The moon’s gravity is now so small that it exerts the same upward pull as a pea held about 20 inches above your head. But some people still believe that even this weak gravitational power from the moon effects human behaviour.

Lunar influence

The moon’s 29 day orbit around the earth is called a lunar cycle. The full moon has long been associated with mystery, aggression and horror. Studies show that the behaviour of some animals; changes during the lunar cycle, some creatures hold breeding cycles dictated by the moon. Scientists have studied the link between predation and the full moon. Researchers think that the increased moonlight helps some nocturnal hunters track and kill their prey. Although the idea that wolves howl more often on a full moon is nothing more than a myth, yet if some mammals do become more active on a full moon might this aggressive lunar trait extend to humans?

A look into the distant future.

Half a billion years from now – the moon will be so far away from our earth that eclipses will be a thing of the past.

Less than two billion years hence, with the moon no longer holding our earth on its axis our planet rocks back and forth, the weather goes wild, and life on earth is threatened.

Billions of years into the future - the moon reaches the end of its journey away from the earth, its orbit stabilizes.

Five billion years from now – the sun expands as it nears the end of its life. The earth and moon so inextricably linked in life are together in death engulfed side by side by the awesome heat of our sun.

* (asteroid impacts) the Age of Bombardment

* (Early earth and volcano activities also known as the Hades Era).

Please note: It would have taken too long to insert the explanations of the early earth’s age of bombardment and the Hades era. I’ll make another blog sometimes in the future where I speak about The Age of Bombardment and then again another blog where I’ll explain of early earth known as the Hades Era.

Wish you all a wonderful weekend and a safe week ahead.

Huuugs and love to all

Wabbit