With all of the conditions and circumstances that had to be present for life to develop on this planet, it is amazing that life has not only emerged, but that it evolved to the point that it became capable of manipulating and quantifying it’s environment. So what exactly is life, and is it rare in the universe or is it common as the galaxies?
Science says that Life is an organismic state characterized by the capacity for metabolism, growth, reaction to stimuli, and reproduction. But there is more to life than just these characteristics. There is also sensation, there is experience, there is instinct and there is purpose even in the smallest forms of life, and even rudimentary life is a rare and precious thing. Yes, there are billions, maybe zillions of galaxies, containing countless solar systems, and it would be arrogant to assume that life is not plentiful in the universe. Nevertheless, there are so many prerequisites for the development of life, even simple life forms, it’s a high probability that it’s not something that has happened all that often.
Mammalian life, it appears, could be even more rare, being that there are so many elements and conditions required for it to develop and to survive. The development of sentience (the capacity for self-awareness, the capacity to utilize and manipulate the environment for the benefit of the group or colony) is even rarer, as that would require a series of conditions that would be statistically impossible to be accidentally repeated very often.
So what are the conditions necessary for the development of simple forms of life? We already know that we are not able to define life, and our limited knowledge of life is based on the only reference system available, planet Earth. The discovery of extremophiles, microorganisms that can develop in extreme conditions, has expanded the window of possibilities for the existence of life in the universe. But what can we say about the conditions required for life?
In a classical paper presented by G. Wald in 1964 to the US National Academy of Sciences, it was established that life requires:
• the presence of liquid water;
• the elements needed for metabolism and reproduction;
• a source of energy; and
• suitable environmental conditions.
Of these conditions the most important is the existence of water in a liquid state. All the current space missions designed for the search of life in the universe have a common obsessive instruction: look for water.
However, other conditions also play a decisive role. Without certain other elements, a sufficient source of energy and stable and protective surroundings, it is difficult to imagine that life could survive for very long.
In addition to water, life requires other elements that have both structural and metabolic roles. As will be seen, some of these form part of the various “vitamins” that human beings need to survive – others are known as “trace elements” and they are equally important for our well-being.
• atomic carbon (C) which comes mainly from Carbon Dioxide (CO2);
• atomic hydrogen (H) which can be generated from water (H2O) and molecular Hydrogen (H2);
• atomic oxygen (O) from water (H2O);
• atomic nitrogen (N) from molecular Nitrogen (N2);
• atomic sulphur (S) from hydrogen sulphide (H2S); and
• atomic phosphor (P) obtained from the phosphatic anion (PO43-); together with
• monovalent and divalent metals like sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu) and zinc (Zn); as well as
• anions like that of chlorine Cl-.
Interestingly enough, most of these elements are the ones that are most abundant in the Universe. Also the molecules used to obtain them by the living systems are quite common. So it is reasonable to conclude that life is made of components that are easily available in the environment. Of course, you have to have a planet where those components are available in its environment, and not all planets have that environment. Some planets are primarily gas; some are primarily frozen ice balls, and not water ice either. Some planets are too far away from their suns, and some are too close. Some are too large and some are too small. What’s required is what is called “a rocky planet,” which is a planet that is composed primarily of silicate rocks or metals. Only a rocky planet has the elements and minerals that are necessary to support the development of complex life forms. Then, that rocky planet has to be located, within it’s solar system, not too close and not to far from it’s primary, or sun. This, according to science, is called “The Goldilocks Zone”. The Goldilocks principle states that a planet must neither be too far away from, nor too close to the sun to support life. Either extreme would result in a planet incapable of supporting life. The Goldilocks principle for planets supporting life would have relatively few parameters if the life was to remain unicellular or possibly multicellular at best, however the number of critical parameters needed for reptilian life would be greater, and even more and stricter parameters would be required for the emergence of mammalian life. Thus, the probability for the emergence of a particular type of life on a planet would be directly proportional to the number of essential physical, chemical and astrological parameters, upon that planet, required to allow for that particular classification of life to arise. The Goldilocks principle that appears to govern the development and survival of life would also include the optimum position of the planet in the Milky Way galaxy (free from lethal radiation or frequent collisions) as well as the age, size and stability of the planetary sun. Such a planet is colloquially called a “Goldilocks Planet”. My gosh! Just think of all the parameters that had to be met before life could evolve! And we aren’t finished yet, because there are even more so-called happy accidents had to occur before mammals could evolve, preliminary to the development of Homo sapiens. For instance, our Earth is generally protected from large comets and asteroids due to the amount of gravity imposed upon them by Saturn and Jupiter, the imposing Centuries that guard our solar system. And still there is more! Earth’s climate would be much different, and Earth’s rotation would be much slower if we did not have a moon. Back in Earths infancy, it didn’t have a moon. The most popular theory as to how Earth got it’s moon is, back when the solar system was still young and still in the process of establishing the planetary orbits, there was a lot of debris floating around, coalescing into planets or crashing into the planets that had already formed. This period lasted for a few billion years, and near the end of it, a planet sized object, bumped into earth and glanced off, dislodging a significant portion of both planet earth and this object. This debris was captured in Earth’s orbit, and after a few million years it coalesced into what we now call our moon. Before the moon, Earth was not tilted on its axis, like it is today. It had a slower rotation period and there were no seasons, as we know them today. The Earth’s climate was hotter than it is now, and was not a very hospitable place, possibly due to its almost circular orbit around the sun. Then, this planet sized object slammed into Earth, and out of the violence of that event came conditions more suitable to the development of more complex life forms. The impact knocked Earth into an elliptical orbit and left Her tilted on Her axis. After the moon formed, from the debris in orbit around Earth, tides began to pull on the planet, generating the rhythms of life, and the atmospheric conditions that generate weather. Now, life would flourish, but not mammals, yet. As we all know, mammals didn’t really flourish until after the demise of the dinosaurs, and that my friends, was another happy accident. This time a huge asteroid hit the Earth and the resulting violence changed the temperature of the planet, quite rapidly, resulting in the deaths of several billion dinosaurs. Nevertheless, the more adaptive burrowing animals (mammals) managed to survive and the rapid changes in temperature forced the mammals to not only adapt, but to grow larger and flourish. It took several billion years before humanity arose, and a few more to develop into mechanized societies. That’s the last happy accident. In the history of the world there have been collisions and chaos, cataclysmic volcanic and seismic events and then rebirth, and reformation. It has only been in the last few thousand years that the climate and conditions on this planet has become calmer, the volcanic and seismic activity diminished to a level that was conducive to the development of societies, nations, the industrial revolution, and the possibility of a planetary society that is on the verge of developing a means through which to spread itself throughout the galaxy. Could all of this have happened by accident? Even scientists marvel at all the amazing coincidences that were required for the development of life, as we now know it. It would seem to me that if so many specific parameters had to be met, and we have yet to find anywhere else in this solar system where those parameters have been met, and although SETI and scientific teams and astronomers, all over the world are combing the cosmos for any evidence of life elsewhere, we have yet to find it. That doesn’t mean that it doesn’t exist elsewhere, but it does drive home the reality that, at least for now, we haven’t found it and that so far our Blue Earth Home is a rare gem. I am sure that Earth has a Soul-Mate Planet out there somewhere and that, one day, we will meet our long lost brothers and sisters. Nevertheless, until then, every time you think your life has no purpose, just think of what it took for you to even be here. Surely, there is a plan for our Blue Earth Home and a plan for Earth’s people. I believe that if we look for it, we will find it’s secrets are hidden deep within each human heart.

