Goldilocks Zone

Have you ever wondered why the orbit of the earth around the sun is the way it is? Has it ever occurred to you that if the orbit was a few percentage points closer or farther away, we would either burn up or freeze up? Would it matter if the earth’s axis was at a different tilt? Are we accidentally in a ‘just right’ zone like the porridge, chair and bed Goldilocks loved in the fable about the three bears? Let’s check it out.

“If our planet were just a little closer to the Sun, a runaway greenhouse effect would render it unliveable. Life depends on liquid water — which Earth has lots of. But if the planet were to receive about one-tenth more solar radiation than it does now, that blessing would become a curse. Water vapour traps heat just like atmospheric carbon dioxide, and on a warmer world more water would evaporate, boosting the greenhouse effect and thus trapping even more heat. That destabilizing feedback, or runaway greenhouse effect, would eventually rob the planet of its oceans”, says Jérémy Leconte, a planetary scientist at the Pierre Simon Laplace Institute in Paris. Fortunately the orbit is stable. It has been estimated that the inner edge of the Solar System’s habitable zone is about 142 million kilometres from the Sun. Earth orbits the Sun at an average distance of 149.60 million km (92.96 million mi), leaving not much room for change. The Earth’s axis of rotation is at a constant 23 ½ degree tilt with respect to its orbit around the Sun, resulting in the change of seasons. The physical characteristics of the Earth include its composition which is just right for supporting vegetation and mining potential. It also has gravity and magnetic force fields to keep things in place and to enable navigation.

In summary: the earth’s orbit is just the right distance from the sun, its axis is tilted at about 23.4 degrees which is just right for creating seasons, the gravitational pull is just right to prevent us, and all things, from flying off into space, and the composition of the earth’s crust is just right for producing food, resources and the water needed. We’d better not spoil it!
Thank you, Lord, for that wonderful arrangement!

Henry Wiebe