Space

Published on February 4th, 2010 | by Yellow Magpie

23

The Moon: Vital In The Creation And Preservation Of Life On Earth

The Moon Photo By Luc Viatour

The Moon is something we take for granted. A large grey disc silhouetted against the night firmament. It is almost so familiar to us all that it raises no eyebrows. We ponder no questions as its tranquil presence casts its immense shadow upon us.

Yet, it is this all too familiar rock that is responsible for nearly every aspect of life on our planet and consequently we owe our debts to it. Not only is the Moon the key catalyst in the creation of life but it is also the key reason why we still have life on our small and inconsequential planet.

The Moon

The Strange Phenomenon Of The Moon

Nearly the size of Mars, the Moon is huge in comparison to the moons of other planets in the Solar System. The Moon would have an iron core if it was of the same age as the rest of the planets especially taking into account its size.

Nevertheless, it does not, confirming that it is younger than the planets of the Solar System. Scientists have until recently been puzzled about the origins of our nearest neighbour. Various theories have been put forth about the Moon’s origins. All of which have been disproved to some degree.

More recent evidence, through the use of computer simulated reconstructions, have now shed light on the long held problem and a clear theory has emerged.

A Cataclysmic Collision

Over four billion years ago, early in our planet’s infancy, a cataclysmic collision occurred between the Earth and a rogue planet, which has been named, Theia. This collision completely obliterated the surface of the Earth and completely ripped Theia apart.

However, what resulted was our present circumstances as the Moon formed out of this near apocalypse.

The Earth Rising From The Moon’s Surface

Four and half billion years ago Theia, sometimes called  Orpheus, hit the Earth. This impact over time led to the creation of the Moon and also dramatically affected life on Earth.

The Improbable Unlikelihood

What is remarkable is that in order for our present reality to have a happened a very precise set of circumstances had to be set in motion.

The collision between the planets, Earth and Theia, had to have occurred at a precise angle and an exact speed. Not only that, but in order for life to have occurred on Earth, the collision would have had to have happened at just the right distance from the sun. Too far away and there would not have been sufficient heat to create life, too close and the temperatures would have been far too hot and we would have had no oceans.

If the impact did not occur at the right angle and appropriate speed the Moon would never have existed. The so-called Roche radius is an area in which debris from a planet will either disperse or coalesce into a shape.

Formation Of The Moon

The impact sent debris outside the Roche radius, 22,000km (14,000 miles) from the Earth. Over a period of a century or so the Moon coalesced into its now familiar shape, forming the impressive satellite that watches over us from little more than dust.

However, the situation is even more complicated. If there had been an head-on impact the resulting debris would not have cleared the Roche radius and would have eventually returned to Earth. This is much like the fate that awaits the rings of Saturn, which is most likely debris from an impact that failed to clear the Roche radius.

If the angle of collision was just a fraction off, another possibility is that two moons would be the result. These two moons however, would prove to be unsustainable and would ultimately return to Earth. The impact that resulted in life on Earth happened to be a near-miss, the merest of glancing blows between Theia and our planet.

The Planet Mars Above The Moon

A Very Different Landscape

If one was to travel back in time to the early dawn of our lunar cousin, a very different sight would await. For a start, the Moon would have been much more active, being constantly bombarded by large objects crashing onto its surface. But this would not be the first thing to gain one’s attention. The Moon would have looked enormous in comparison to today. Due to its close proximity to Earth, it would have appeared 15 times bigger in the night sky.

Consequently, the gravitational forces that the moon exerted upon Earth was far stronger than it is today. In fact, over 4000 times stronger.

These huge gravitational exertions helped to reduce the Earth’s rapid rotation from a four-hour day to our present 24 hours. The tidal activity also had the effect of repelling the Moon, causing it to slowly retreat away from the Earth over time. The Moon is now 370,000 km (234,000 miles) from the Earth. The Moon is still retracting from the Earth at a rate of 2 cm (one inch) a year.

The Moon’s Mare Imbrium Taken By The Apollo 15 Crew

The Moon And Maintaining Life On Earth

The Moon maintains our constant tilt. The axis of the Earth is critically reliant on the Moon. Unstable shifts in the axis would reek havoc with the Earth’s climate. The world as we know it would become completely inverted. Places that experience drought could become flooded and locations that are frozen could become tropical hot spots.

Making the Earth more inhospitable is the fact that there would be huge climatic fluctuations. One moment it could be arid in a particular region, the next moment the same region could be under several feet of water as the Earth wobbles along an unstable axis. It is difficult to see how under such circumstances life could survive on Earth under such extreme climatic changes.

The Present Impact Of The Moon on Life

Some would argue that presence of the Moon, especially a full Moon disturbs the normal patterns of human behaviour. Other animals are also affected by the full Moon with many species, particularly marine life, reproducing under the shadow of its full face.

Plans To Mine The Moon

Currently, there are plans afoot to mine the Moon for a valuable substance that may be the answer to our energy crisis. However, given what we now know about the  importance of the Moon to life on Earth, mining our lunar neighbour may lead to serious problems for our own planet.

Highly Recommended

Check out Yellow Magpie’s The Solar System And Beyond: A Guide To The Cosmos.

Cosmos is a highly recommended book. It contains large, full-page pictures of the known surface of the Moon and insightful writing on the subject by the highly competent author, Giles Sparrow.

Amazon.co.uk
For people living in Ireland or the United Kingdom, you can access: Cosmos from here.

Amazon.ca
For those who live in Canada, you can obtain: Cosmos here.

Amazon.de
For Germany: Cosmos.

Amazon.fr
For France: Cosmos.

About the Author

Yellow Magpie

Related Posts

Dwarf Planet Sedna: The Most Distant Object Ever Observed In The Solar System →

Dwarf Planet 2007 OR10: Formerly Known As Snow White →

Dwarf Planet Makemake: The Creator Of Humanity →

Weywot: Dwarf Planet Quaoar’s Moon →