Reasons to Believe

Is the Solar System Special?

Since its inception 22 years ago, Reasons To Believe has held the position that our Solar System is extremely unusual, probably unique in the observable universe.

We base this view on the Solar System’s various characteristics required to provide the long-term conditions necessary for life in general and especially for the advanced life on Earth. On the other hand, it is the contention of the naturalistic scientific community, for the most part, that there is nothing unique about our Solar System or Earth. This viewpoint is usually referred to as the Principle of Mediocrity (an extension of the Copernican Principle), the idea being that since the Earth is not at the center of the Solar System, we are not special like once thought. In the words of Carl Sagan from his PBS series Cosmos,

For most of human history we have searched for our place in the cosmos. Who are we? What are we? We find that we inhabit an insignificant planet of a hum-drum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.

While this is the prevalent view, there are some nontheist scientists who have argued an approach not too different from that of Reasons To Believe; namely that Earth is rare. However, the growing body of evidence for exoplanets—planets orbiting stars other than our Sun—seemed to provide support for the non-uniqueness of our Solar System.

A recent report on computer simulations of the birth of planetary systems appears to put the ball back into the “uniqueness” court. E. Thommes and his colleagues at Northwestern University examined the more than 250 planetary systems, including our own, and developed a sophisticated model for the formation of planetary systems from beginning to end. They have numerically simulated this model using a variety of boundary conditions to reproduce results that are in agreement with some of the key trends observed in the properties of the exoplanets. These same simulations demonstrate that our own Solar System represents a rare case where the gas giants form but do not migrate into the inner parts of the planetary system, and all the planets achieve stable circular orbits. In the words of one of the authors,

We now better understand the process of planet formation and can explain the properties of the strange exoplanets we’ve observed. We also know that the Solar System is special and understand at some level what makes it special.

Undoubtedly, skeptics will remain and certainly this model will require development and improvement, but RTB scholars remain convinced that the more we learn about the special characteristics of our Solar System, the more we will discover the “fingerprints” of its Designer.

Other related resources of interest:

Extrasolar Planets webpage

Subjects: Solar System Design

Dr. David Rogstad

Dr. Dave Rogstad received his PhD in physics from Caltech and worked over 30 years for NASA’s Jet Propulsion Laboratory. Though now retired, Dave continues to serve as an RTB board member and participates regularly in several RTB podcasts.