Monday, July 31, 2017

Life As We Know It

The combined information in two articles within a recent edition of Science News Journal[1] can lead to some intriguing speculation. One of the greatest assumptions of the search for extraterrestrial life is that we will likely find life where there is water. This is a valid hypothesis, for we know that life, as we know it on earth, requires water as a starting point. Single-celled life on earth is thought to have first developed in the sea in structures resembling soap bubbles,[2] bacterial cells are approximately 70% water, and humans are known to be 50-60% water.[3] So, life forms with which we are familiar require large quantities of water.

But, what might we find on other worlds? A recent article entitled, “Potential ingredient for alien life found on Titan,”[4] suggests that life might be possible in places where the predominant chemicals are liquid methane and vinyl cyanide. One can readily guess from the names of these chemicals that such life would be incompatible with life as we know it on earth, but might be possible in other forms. Primitive cell structures based upon water and proteins can form on earth and it is possible that such cell structures might also form, given the right conditions, in oceans of methane with vinyl cyanide. Poly-vinyl linkages of such compounds could form protein-like structures that encase other molecules that, in turn, act like RNA and DNA equivalents. Titan, a moon orbiting around Jupiter has such chemistry and could harbour some form of primitive life.

The other article in the same edition of Science News reports on the discovery of the first exo-moon. An exo-moon is a moon which orbits a planet which, in turn, orbits around a star in a distant solar system. The existence of such exo-moons expands our knowledge of potential environments where life might be possible. There are very few exo-planets that have been found to be in what are known as habitable zones. This exo-moon discovery suggests that there may be a great many more potential habitable zones in which liquid water exists. Couple this finding with the possibility of vinyl cyanide-based life forms, and the field in which to search for other life forms expands significantly.

Is life a once in a universe happening? Is Earth the only place in this universe where replicating, auto-sustaining, growing, and dying creatures exist? The search will go on as we continue to speculate about what might be possible. Earth is one small planet in a vast galaxy within a vast universe. The mind of the Creator is unfathomable when it comes to questions regarding why he created so much space. Are there other patterns of life out there? Did they spontaneously evolve? Was there a Master plan? Let us continue to ask good questions.

[2] Partitioning may have begun from cell-like spheroids formed by proteinoids, which are observed by heating amino acids with phosphoric acid as a catalyst. They bear much of the basic features provided by cell membranes. Proteinoid-based protocells enclosing RNA molecules could have been the first cellular life forms on Earth.

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