Was it designed ? Our Unique Solar System
MANY factors combine to make our part of the universe unique. Our solar system is located between two of the Milky Way’s spiral arms in a region that has relatively few stars. Nearly all the stars that we can see at night are so far from us that they remain mere points of light when viewed through the largest telescopes. Is that how it should be?
If our solar system were close to the center of the Milky Way, we would suffer the harmful effects of being among a dense concentration of stars. Earth’s orbit, for example, would likely be perturbed, and that would dramatically affect human life. As it is, the solar system appears to have just the right position in the galaxy to avoid this and other dangers, such as overheating when passing through gas clouds and being exposed to exploding stars and other sources of deadly radiation.
The sun is an ideal type of star for our needs. It is steady burning, long-lived, and neither too large nor too hot. The vast majority of stars in our galaxy are much smaller than our sun and provide neither the right kind of light nor the right amount of heat to sustain life on an earthlike planet. In addition, most stars are gravitationally bound to one or more other stars and revolve around one another. Our sun, by contrast, is independent. It is unlikely that our solar system would remain stable if we had to contend with the gravitational force of two or more suns.
Another factor that makes our solar system unique is the location of the giant outer planets that have almost circular orbits and pose no gravitational threat to the inner terrestrial planets.* Instead, the outer planets fulfill the protective function of absorbing and deflecting dangerous objects. “Asteroids and comets hit us but not excessively so, thanks to the presence of giant gas planets such as Jupiter beyond us,” explain scientists Peter D. Ward and Donald Brownlee in their book Rare Earth—Why Complex Life Is Uncommon in the Universe. Other solar systems with giant planets have been discovered. But most of these giants have orbits that would endanger a smaller earthlike planet.
The Role of the Moon
From ancient times, our moon has filled mankind with wonder.One important way in which the moon affects life on earth is that its gravitational pull causes the ebb and flow of the tides. Tidal movements are thought to be fundamental to ocean currents, which, in turn, are vital for our weather patterns.
Another key purpose that our moon serves is that its gravitational force stabilizes earth’s axis with respect to earth’s plane of orbit around the sun. According to the scientific journal Nature, without the moon, the inclination of earth’s axis would wobble over long periods of time from “nearly 0 [degrees] to 85 [degrees].” Imagine if earth’s axis had no tilt! We would miss the delightful change of seasons and suffer from a shortage of rain. The earth’s tilt also prevents temperatures from becoming too extreme for us to survive. “We owe our present climate stability to an exceptional event: the presence of the Moon,” concludes astronomer Jacques Laskar. To fulfill its stabilizing role, our moon is large—relatively larger than the moons of the giant planets.
Yet another function of the earth’s natural satellite, as noted by the writer of the ancient Bible book of Genesis, is that the moon serves as a light by night.—Genesis 1:16.
Chance or Purpose?
How is one to explain the concurrence of multiple factors that make life on earth not only possible but also enjoyable? There appear to be only two alternatives. The first is that all these realities are the casual product of aimless chance. The second is that there is some intelligent purpose behind it. You decide.
(adapted from w07 2/15 pp. 4-7)