Facing Reality About Life on Other Planets, 5: Water and Rock
by Dr Henry Richter
There is much interest in searching for life elsewhere in the Universe. In previous articles I talked about the many criteria describing conditions and circumstances required to establish and maintain life on a planet. I talked about the importance of the location of the planet in its solar system. The location of the solar system in its galaxy is important as well. Being in the habitable zone around the host star sets the temperature. Having a suitable atmosphere, a moon, and a magnetic field each play a part in allowing life. Now, homing down to a planet’s surface, let’s consider the presence of water: liquid water.
Water is essential to life – and not just liquid water, but with the proper purity, neutral acidity, and chemical content. Water is an essential ingredient in living cells, both plant and animal. And there must be ample water. In consideration of a human colony on the moon or mars, possible sources of water have been found, mainly small deposits of water ice, but these are not sufficient for the development of life forms, at best—just the sustenance of existing life.
Water is a phenomenal substance. It is the only liquid that can dissolve a wide variety of organic and inorganic molecules. Other planets have liquid ammonia or methane which dissolve a few things, but the capability is very limited. Living cells use water, not ammonia. The familiar structure of a water molecule, consisting of one oxygen atom and two hydrogen atoms, gives it the familiar “mouse ears” configuration. Perhaps because of this structure, the hydrogen atoms on adjacent water molecules interact with what is called a hydrogen bond. When water freezes, the hydrogen bonds line up in such a way as to expand the water, resulting in a solid (ice) which is less dense than the liquid water, and thus it floats. This is a unique property that very few other liquids possess. When most liquids change from the liquid to solid state (i.e., when they freeze), they become more dense, and therefore sink to the bottom of the liquid. If water behaved this way, we would not have much liquid water on earth, because ice would sink to the bottom of the ocean, lakes, rivers, and reservoirs, accumulating upward but never melting. Maybe there would be a few centimeters of liquid water on top on a warm day, but not much. Water as a chemical works best in a temperature range of 50° to 100° C which brings us back to those factors that determine a planet’s temperature. So let me say, water was created in a special way, again to allow life to exist.
Ample water means oceans or major lakes will exist. These would allow a water cycle transporting water over solid land to supply life forms needed fluid to carry on metabolism and cellular processes. Just water vapor in an atmosphere would not do it. An ongoing intake and outflow of water to cells is required for life. This means a ready supply of liquid water. So, a search for oceans will certainly top the list when it becomes possible to closely examine exoplanets.
Saltwater vs freshwater. The existence of water on our earth is interesting. Water is found in two conditions: fresh and salty. I believe everything exists as it is for a purpose, so a salty ocean accomplishes something. Having a doctoral degree in chemistry should give me a clue as to what the salt does, but I can only make some suggestions. The swimming pool at our village has salt, as did a neighbor’s pool in Palm Springs, and the reason for the salty pool was to generate a small amount of chlorine (salt is sodium chloride) to avoid having to add chemical chlorine to rid the pool of bacteria or other contaminants. So maybe the salt helps keep the ocean from being overrun with microbes. The salt lowers the freezing point of the ocean as well. It increases the conductivity of water, contributing to temperature regulation. What about fresh-water lakes? I know they are more subject to contamination, but plant life, particularly nearby marshes are instrumental in clearing the water. Groundwater entering lakes is also filtered by soil and rock through which it passes. In addition, most lakes (with exceptions like the Dead Sea and the Salton Sea) have an inlet and outlet that permits new freshwater to replace the old.
Rocks and Minerals
In addition to water, dry land is required for an ecosystem. True, there are plants and animals that thrive in a watery environment, but that makes for a limited set of forms and creatures. The movie Waterworld (1995) portrayed humans trying to exist in a planet completely covered by water. They had to develop a pseudo-land like environment to operate. It was, of course, quite weird and awkward. To have higher forms of life like humans, some fraction of the planet needs to be solid land—and not just solid land, but a rocky surface. This is another necessary criterion for life.* I do not know if anyone is able to compute the optimum ratio of sea surface to land surface on a planet to best support higher forms of life, but a good quantity of both types of surfaces are undoubtedly necessary.
The rocky land provides a source of chemical elements, minerals, and compounds required for both plant and animal life. Other types of surfaces could be imagined, but a chemical surface such as ammonium chloride or calcium carbonate would not support life. Plants are required for the nourishment of animals. They provide fuel for metabolism as well as substances such as vitamins and some minerals like iron and calcium. It is amazing that many of these nutrients are needed by animal bodies but do not seem to be needed by the living plants that take them up from the soil (processed rock) and synthesize them. So a rocky surface on a planet can be listed among the requisites for the existence of life.
Lastly, somewhat related to the composition, form, and makeup of a planet, is the requirement for plate tectonics in the material under the surface. This results from the underlying rock being formed in large sheets under the continents and oceans which can move as a large mass. These sheets move against each other and over and under each other. This churns up the material, mixes it, and refreshes it. It is a very slow process, at least today. This movement of the plates also wrinkles the rocky surface, creating mountains and ocean trenches. When the plates move over places where hot magma wells up from the hot interior of the planet, they are sometimes penetrated, allowing the molten magma to reach the surface in the form of volcanoes. Many believe plate tectonics is also essential for the development of life (at least higher forms of life).
At this point in the series we have examined some 15 requirements an exoplanet must meet to allow for complex life. More factors can be added to our growing list, but the emerging picture is clear: life cannot survive just anywhere, and by meeting all these requirements perfectly, our earth is very special, indeed.
*Notice that evolutionists believe the large mammals in the ocean came from land. —Ed.
**It’s interesting that Venus, without plate tectonics, has volcanoes but a relatively low-relief surface except for one spot, Maxwell Montes, named for Bible-believing scientist James Clerk Maxwell. —Ed.
Dr Henry Richter, a contributing science writer to Creation-Evolution Headlines, was a key player at NASA/JPL in the early days of the American space program. With a PhD in Chemistry, Physics and Electrical Engineering from Caltech), Dr Richter brings a perspective about science with the wisdom of years of personal involvement. His book America’s Leap Into Space: My Time at JPL and the First Explorer Satellites (2015), chronicles the beginnings of the space program based on his own records and careful research into rare NASA documents, providing unequaled glimpses into events and personnel in the early days of rocketry that only an insider can give. His next book, Spacecraft Earth: A Guide for Passengers, is due out later in 2017. For more about Dr Richter, see his Author Profile.