Unique Planet Earth

 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) 

 

Rare Earth

 So far as we know Planet Earth is the only place where life exists in our vast universe. Finding life apart from our own solar system would be a monumental discovery. We speak of not only human life, but any sort of life. This includes some of the more than 8+ million separate species of life. Our planet teems with life—all sorts of life—human life created In His Image, and many other forms of life.

We do not assert that life beyond the confines of our Planet Earth is impossible. Our personal belief is that the existence of life on another planet within our Solar System or beyond is highly unlikely because physical conditions on other planets or planetary systems are vastly different than conditions on Planet Earth. Radio signals traveling at the speed of light could not cover even a tiny fraction of the distance across the known universe, estimated to be 92 billion light years by some scientists. Even if we traveled one light year (the distance light travels in one Earth year) we would travel an insignificant distance in our quest to communicate with other life forms in our universe. Likewise, alien life forms are unable to communicate with us via electromagnetic radio signals.

Famous nuclear physicist Enrico Fermi once ventured outside his field of expertise during a scientific conference. He wondered, “Where is everybody?” His scientific colleagues realized he was inquiring about extraterrestrial life. The statement became known as the “Fermi paradox.” Many other scientists have passed judgment on the possibility of alien life: 

https://jasscience.blogspot.com/2018/07/dismissing-et.html

As young people we may have mused on the possibility of life at other locations in our vast universe. We have commented on this question several times in past posts:

https://jasscience.blogspot.com/2018/07/alone-in-universe.html

The question concerning life outside our Solar System has been asked even by creationist theologians. If our God is the Creator of All Things, we would expect alien life had its origin in a divine act of fiat creation by the God described in Genesis 1:1-2. This scenario runs counter to evolutionary theory that living creatures could self-assemble naturalistically without any input from the Divine Creator:

https://jasscience.blogspot.com/2018/07/really-alone.html

Planet Earth has physical conditions unlike any other planet (exoplanet) in our vast universe. Scientists who study this topic are called astrophysicists. Our links discuss just a few topics studied by scientists in this specialized field:

https://jasscience.blogspot.com/2018/07/earth-exceptional-or-one-of-kind_31.html

Our planet has major “spheres” of physical characteristics. Three of the spheres are (1) atmosphere (2) hydrosphere, and (3) lithosphere. Each sphere possesses sub-spheres. For example, the atmospheres consists of the troposphere, stratosphere, and several other sub-spheres.

“Earth’s spheres—atmosphere, hydrosphere, and lithosphere work together to sustain life. Each sphere plays a distinct yet interconnected role in maintaining the planet’s balance. The interconnection between these spheres support diverse ecosystems and ensure environmental stability. Understanding these interactions provides insight into their importance in sustaining life.” (BiologyInsights.com 10/24/2024)

As we investigate the exoplanets discovered in our minuscule corner of the Milky Way galaxy, we are struck with the small number of planets existing in the “habitable zones” around their home stars. Planets must exist within a specific temperature range, having an appropriate amount of liquid water pooling on its surface, and a precise proportion of elements and compounds composing its lithosphere. If the educated guess of astrophysicists that roughly 50% of exoplanets are rocky instead of gaseous, we quickly eliminate half of the universe’s planets from habitability. There are thousands of additional physical parameters which, if absent, reduce the chances of planetary habitability to near ZERO.

Does extra-solar life exist? The question is impossible to answer. It is possible, however, to exult in the uniqueness of Planet Earth. Our God created the universe to be inhabited by humanity and more than eight million other species of life: “For this is what the Lord says—he who created the heavens, he is God; he who fashioned and made the earth, he founded it; he did not create it to be empty, but formed it to be inhabited—he says: I am the Lord, and there is no other.” (Isaiah 45:18 NIV)