by Dr. Neal Doran
January 11, 2011
After following the report of a distant, Earth-like planet in the scientific literature, a Time magazine article reminded me of the caution required in reading news reports on science. Artistic renderings of this planet’s red dwarf “sunsets” can be found on the Internet, but what should a properly informed scientific position be for claims such as these? How should we as Christians view these so-called “findings?” As with so much of what today is presented as scientific fact, I would suggest a respectful skepticism.
The reason is that finding a planet like Earth anywhere in the universe is extremely unlikely. Gliese 581 g is a candidate planet circling a red dwarf star in the Libra constellation, 20 light years away. The rarity of such a find makes it newsworthy. If you are looking for a world where life might thrive, a planet must be at the right temperature for water to exist in liquid form. Therefore, it needs to orbit its sun, or star, in the so-called “habitable zone.” Astronomers refer to such elusive worlds as “Goldilocks” planets, celestial bodies in which, like the children’s story, everything must be “just right” -- not too hot, not too cold. Gliese 581 g seems to fit these minimum criteria. And while no one knows whether the planet actually contains so much as a drop of water -- another requirement for life -- proper temperature is nonetheless one of many of life’s requirements.
Yet the discovery in itself raises a more important question. For instance, if such a discovery is so unlikely -- the odds so remote of duplicating earth’s almost immaculate fusion of favorable conditions -- why do scientists continue the search? The primary motive of researchers seeking the existence of such planets is rooted in the scientific speculations of the 1940s and ‘50s. The Goldilocks planet expectation is, in fact, an echo of something known as the “evolutionary synthesis.” Since theorists concluded that the cosmos teemed with life, the logic followed that if life evolved on Earth, then the chemical evolution of life (a.k.a., abiogenesis) must happen as a rule -- not an exception -- throughout the cosmos. Why should Earth be unique?
Jupiter's moon Europa
Ice patterns on the surface of Europa provide evidence that liquid water exists below.
At least Jupiter’s Europa leaves open a door for testability. This open door, in turn, shows the difficulty of the pursuit. For example, Europa’s estimated ocean depth is 60 miles. (For comparison, our deepest ocean trench is a paltry seven miles.) Such depth would create a crushing water pressure without parallel on Earth. Consequently, this water would also be extremely saline (and likewise hostile to life). On Earth, coastal evaporation reduces ocean salinity. But Europa lacks both continents and sufficient heat to drive evaporation. No such scientific observation -- let alone informed inference -- is possible for exoplanets such as Gliese 581 g. Verification of oceanic salinity -- if oceans exist at all -- is unobtainable through the lens of a telescope. This is particularly true when all we will ever see is its sun. Jupiter’s moons at least allow an occasional satellite flyby.
The Evangelical community is too often polarized between a derisive disregard of science, on the one hand, and unconditional embrace of its every assertion, on the other. Scientific research is good. Yet speculative ideas beyond the reach of physical investigation are frequently the fuel for ideologically driven bandwagons. As a believer, I am open to a strongly evidenced case that an extraterrestrial body may contain life. Yet my philosophical framework provides no reason to think this is a fruitful use of resources. Scientific philosophies that remove God from reality eventually produce alternatives to His existence. Unfortunately, these seem to result in zealous pursuits of the highly improbable. As a result, the embrace of the nearly impossible becomes a passionate crusade.
If weak speculation was not problematic enough, my search of the scientific literature revealed an additional problem. Astronomers now doubt that Gliese 581 g exists at all; it may have been the result of an error in data analysis. This underscores my point: when both reason and evidence fail, skepticism of theoretical conjecture is the best path.
Dr. Neal Doran teaches biology at Patrick Henry College. His fields of interest include invertebrate and micropaleontology, morphometrics, the metaphysics behind modern biological thought, and origins.