The purpose of our current post is to promote reader interest in a fascinating topic—the uniqueness of our physical home in the universe. In one sense, every planet in the universe is unique—one of a kind. Unique can mean unparalleled or without equal. No two planets are identical in every respect. Unique, more generally, connotes unusual or special. Our planet is certainly unusual and special to a high degree. If Earth is the only location in our vast universe where life exists, we may assign the adjective “unique” to our planetary home.
We mention a small number of life supporting conditions on our unique planet in this article. Earth’s atmosphere, hydrosphere, and lithosphere provide physical conditions which, taken together, provide a unique site for life—human life in particular. Science journalists usually describe only a small fraction of the many physical conditions necessary for the existence of life.
Many of the billions of planets in our universe have an atmosphere. Most atmospheric gas mixtures are not life-friendly. In our Solar System, Earth is the only planet to have an abundant supply of life-friendly oxygen and nitrogen. The chemical properties of these two gases are subjects for detailed study. The atmosphere of Venus, next closest planet to the sun, sometimes called Earth’s twin, has an atmosphere of 96% carbon dioxide. Its atmosphere is nearly 100 times as dense as our planet. Its surface temperature is blazing hot. Not only would Venus’s atmospheric density crush our bodies, but we would be quickly baked by temperatures hot enough to melt lead. Venus is Earth’s twin only in its similarity in size and mass.
Planet Mars is the fourth planet from the Sun. Its atmosphere is composed of exceedingly thin carbon dioxide. Not only would we suffer from frostbite (or worse) on its surface, but humans would need a pressurized space suit with a temperature conditioning system able to provide adequate water and oxygen, as well as the capability of removing exhaled CO2 and other products of metabolism. Mars is the only planet humans realistically contemplate visiting in person in future years. Elon Musk has produced incredible reusable rockets through his SpaceX technology company. Musk contemplates a manned Mars visit sooner than most people imagine!
The tiny, nearly airless planet Mercury with its extreme hot or cold surface temperatures is not a worthwhile venue for a manned visit.
Planet Earth is ideally located in the planetary “habitable” zone. Primarily, the habitable zone for planets is a location where much of the water remains liquid instead of solid or vapor. The habitable zone is not too hot and not too cold and does not possess other fatal environmental hazards.
Jupiter, Saturn, Uranus, and Neptune are clearly outside the habitable zone. They are gas giants or ice giants, not rocky planets like Mercury, Venus, Earth, and Mars. Rocky (terrestrial) planets have layers: crust, mantle and core. As a rocky planet Earth also possesses plate tectonics, by which crustal plates slide across the planet’s surface. Elements such as carbon are thereby recycled over millions of years. Geoscientists believe Earth is likely the only planet to manifest life-sustaining plate tectonics.
Interactions among Earth’s atmosphere, hydrosphere, and lithosphere are unique to Planet Earth. These interactions provide for the existence of life. So far as we know, life exists on one planet in the universe, notwithstanding ebullient optimism expressed by many science journalists. It is possible a few planets possess life-sustaining conditions but it is not more likely that life exists on those planets. If the scientific principle of abiogenesis—life springing from non-living material—is true, it would lend strength to the belief in naturalistic “molecules to man” evolution. Our position is that life on Earth is a result of fiat creation events originated by a Divine Creator, not the result of naturalistic evolution.
One outstanding biblical creation passage is found in Isaiah 45:18. We quote the verse once more: For thus says the Lord, who created the heavens (he is God!) who formed the earth and made it (he established it; he did not create it empty, he formed it to be inhabited!): “I am the Lord, and there is no other.” (ESV)
