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. https://en.wikipedia.org/wiki/Evolution_of_cells