Exobiologists study life on other planets. As of today it is a science without a subject, as the Search for Extra Terrestrial Life (SETI), despite more than fifty years of searching, has so far failed to find anything to study. Looking at Earth, however, exobiologists are in general agreement that it is difficult to see how life on Earth could be sustained for a long period of time without a moon like ours. They further agree that it is difficult to see how any multicellular life forms could have arisen or survived without such a moon. It is also reasoned that because the Earth was formed as the result of “random natural processes”, the Moon must have been formed by the same presumably ubiquitous natural processes.

Given this line of reasoning, they conclude there can be nothing special about the Earth – Moon System; therefore the Universe must be full of similar planet – moon systems harboring life. The Moon is considered critical to life, especially higher life forms for several reasons. Among these reasons is the fact that it plays a major role in plate tectonics, which in turn drives a number of geological cycles, such as the carbonate-silicate cycle, on which life is dependent. The Moon is also critical to climate stability, oceanic nutrient circulation and much, much more.

Even more important to these life-sustaining processes is the planet-forming role played by the Moon in the Earth’s history. It is now almost universally accepted by planetary scientists that the Earth took on its present form when it collided with a Mars-size body during the earliest phase of the planets formation. This collision did several things that are essential to making the Earth a habitable planet. Among the most important of these are the stripping away the Earth’s original extremely dense carbon dioxide atmosphere (such as that still retained by Venus) and the super-enriching of the planet’s core and crust with heavy metals. This collision also left behind the small low-density moon that now orbits the Earth.

Fortunately for astronomers new observational techniques and instruments allow observers to detect such collisions in other planetary systems and see if they are as common as is supposed. It is easy to imagine how much dust and debris must be left behind when an Earth-size planet collides with a Mars-size planet. This type of dust cloud is easily detectable from across the Galaxy.

To get a measure of the frequency of such collisions NASA’s Spitzer Space Telescope examined 400 nearby stars that were believed to be good candidates for such a collision, based on the system’s age and other factors. It was originally assumed that about 5% to 10% of the systems would show evidence of such a collision. As it turned out only one system showed evidence of a collision event. This very low frequency indicates that life supporting planet - moon systems such as ours are probably very rare indeed.

Why This Is Important

The discovery of life on other planets is critical to the Materialist faith. The discovery of life on other planets is not central to Christian theology. Christian thinkers entertained such speculations as early as the Middle Ages. Finding extraterrestrial life would neither prove or disprove the existence of God, it would only show that God created life on planets other than just Earth. However, the discovery of extraterrestrial life is absolutely central to atheism/materialism. It is central because it would be taken as evidence for the claim that there is nothing special about the Earth or the origin of life. If life is found elsewhere, this would be taken as evidence that life is just the result of some natural process and consequently is a purposeless process devoid of meaning. As long as no evidence of extraterrestrial life has been found, the atheists/materialists realize they have no “proof” for their beliefs.

Source: “Uncommon Moon” Astronomy, March 2008, pp. 18.

Blogger: Lawrence Vescera, Ph.D., Isaac Newton Institute