Either a beachfront home or a secluded mountain ranch costs far more than a house in suburbia. A secluded mountain ranch with a beachfront on the other hand—now that would be valuable property. The real estate maxim applies in a similar way when considering the location of any potential life-supporting planet—but with far greater consequences than material wealth.
Scientists have identified “habitable zones” around stars where a life-supporting planet could reside. Life’s requirement of liquid water defines one such zone. The high surface temperature of a planet located too close to its parent star vaporizes any water, making the planet uninhabitable. However, moving the same planet too far away from its star freezes all water. Without an ocean in either location, neither life nor beachfront property exists.
But, as recent research highlights, a planet located in the liquid water habitable zone is not enough. All stars emit a form of radiation more energetic than visible light called ultraviolet (UV) radiation. While visible light often drives many of the chemical reactions upon which life depends, UV radiation generally damages essential-for-life molecules. Thus, a planet too close to its star receives lethal doses of UV radiation.2 However, too little UV radiation also poses problems. Strictly naturalistic scenarios for life's origin need the additional energy carried by UV radiation to jump-start the chemical reactions that generate life's precursor molecules. While less constraining for RTB's creation model 3, the amount of UV radiation received by a potential life-supporting planet defines another habitable zone. The planet must reside far enough away from the star that the UV radiation does not destroy all biomolecules, yet close enough for adequate UV radiation to initiate the formation of life's precursors.
These life-favorable water and UV habitable zones overlap for Earth's sun but not for the majority of stars—particularly those stars where astronomers have already discovered planets. Thus, the minimal constraints of forming a planet capable of sustaining liquid water and maintaining the proper amount of UV radiation eliminate most stars as suitable life-supporting candidates.4
Strictly naturalistic models of the universe and the life within it assume that Earth is average in every way, implying that scientists will find many planets with similar characteristics conducive to life. However, as researchers learn more about extrasolar planets, the evidence increasingly points to Earth’s rare, if not unique, capacity to support life—due in large part to its desirable location. RTB’s creation model predicts Earth’s special location as the work of the powerful and caring God of the Bible who explicitly prepared Earth as a home for humanity.
- Andrea P. Buccino, Guillermo A. Lemarchand, and Pablo J. D. Mauas, “Ultraviolet Radiation Constraints around the Circumstellar Habitable Zones,” Icarus 183 (2006): 491-503.
- One cannot invoke an ozone layer like Earth’s as a UV shield because the oxygen responsible for the ozone results from the activity of two billion years’ worth of specific microbial life.
- RTB's model posits supernatural intervention for life’s origin and therefore requires no minimum amount of UV radiation.
- For more details, see Jeff Zweerink, “Habitable Planets Rarer than Originally Thought,” Connections 8, no. 4 (2006), 2-3.