Rare Jewel: Earth-Like Planets May Be Very Rare

Archdiocese of Washington ^ | 02-20-19 | Msgr. Charles Pope

[Salvation]

Rare Jewel: Earth-Like Planets May Be Very Rare

Msgr. Charles Pope • February 20, 2019 •

As we conclude our mini-series on the Genesis accounts of creation and the fall, I would like to ponder God’s magnificent work. We are not here by accident; God has carefully arranged things so that we can exist and flourish. In this regard, I have written a good bit over the years about what is known as the “Rare Earth Hypothesis.” Let’s review some of the basics of this hypothesis.

While most people, including most scientists, believe that there may be billions of inhabitable planets capable of sustaining complex life, the Rare Earth Hypothesis suggests that such a large number is overstated.

This is because there are not just a few things that come together to support life here on Earth—there are many. Here are some:

1. Earth is at just the right distance from the Sun so that water is warm enough to melt, but not so hot as to boil and steam away into space. Water is also able, in this habitable zone (the so-called “Goldilocks” region), to both evaporate and condense at lower levels in the atmosphere, thus permitting a more even distribution of water, and the cycle of water over dry land known as precipitation.
2. For suns to spawn Earth-like planets they must have sufficient “metallicity,” which is necessary for the formation of terrestrials rather than gaseous planets.
3. Earth is in a “habitable zone” within the galaxy as well. Closer to the center of galaxies, radiation and the presence of wandering planetoids make life there unlikely.
4. Earth exists in a disk-shaped spiral galaxy (the Milky Way) rather than in an elliptical (spheroid) galaxy. Spiral galaxies are thought to be the only type capable of supporting life.
5. Earth’s orbit around the sun is an almost perfect circle rather than the more common “eccentric” (elongated) ellipse. Steep elliptical orbits take a planet relatively close to and then relatively far from the sun, with great consequences for warmth and light. Earth’s stable, nearly circular orbit around the sun keeps our distance from it relatively constant, and hence the amount heat and light does not vary tremendously.
6. Two nearby “gas giants” (Jupiter and Saturn) attract and catch many wandering asteroids and comets and generally keep them from hitting Earth. The asteroid belts also keep a lot of flying rock in a stable orbit and away from us.
7. Our molten core creates a magnetic field that holds the Van Allen radiation belts in place. These belts protect Earth from the most harmful rays of the sun.
8. Earth’s volcanism plays a role in generating our atmosphere and in cycling rich minerals widely.
9. Our sun is just the right kind of star, putting out a fairly steady amount of energy. Other types of stars are more variable in their output and this variance can utterly destroy life or cause it to be unsustainable due to the extremes caused.
10. Earth’s fairly rapid rotation reduces the daily variation in temperature. It also makes photosynthesis viable because there is enough sunlight all over the planet.
11. Earth’s axis is tilted just enough relative to its orbital plane to allow seasonal variations that help complex life but not so tilted as to make those variations too extreme.
12. Our moon also has a good effect by causing tides that are just strong enough to permit tidal zones (a great breeding ground for diverse life) but not so severe as to destroy life by extreme tides.

There are many more items on the list (see the first video below), but allow these to suffice. The conditions that come together on this planet such that it is capable of sustaining complex life are complicated, remarkable, and some argue rare in the universe. The ability to support life here is the balance of many fascinating things. We cannot but be amazed at the complexity of life and the intricacies required for it to flourish here. It would appear that for complex life to be sustained, many factors must come together in just the right way. The sheer number of these factors sharply decreases the number of possible Earth-like planets, despite the billions of galaxies and stars.

All this background information leads us to a blog at discovermagazine.com: Earth-is-a-1-in-700 quintillion kind of place. (700 quintillion is 7 followed by 20 zeros!) The blog references a study by Astrophysicist Erik Zackrisson from Uppsala University in Sweden.

Here are some excerpts:

Zackrisson’s work suggests an alternative to the commonly held assumption that planets similar to Earth must exist, based on the sheer number of planets out there …. Current estimates hold that there are some 100 billion galaxies in the universe containing about 10^18^th stars, or a billion trillion …. Probability seems to dictate that Earth-twins are out there somewhere.

But according to Zackrisson … Earth’s existence presents a mild statistical anomaly in the multiplicity of planets …. Most of the worlds predicted … orbit stars with different compositions—an important factor in determining a planet’s characteristics. His research indicates that, from a purely statistical standpoint, Earth perhaps shouldn’t exist …. Researchers are confident in the broader implications of their model: Earth is more than your garden-variety planet.

I write on this topic more in wonder and awe than anything else. Our faith does not require that we believe ourselves alone in the universe. God can, and even might have, created intelligent beings on other planets, beings with whom He interacts and whom He loves.

Neither should we too quickly assume that Earth is not a rare jewel. Statistically, it would seem that we and Earth are rare jewels. Humble amazement at all that it takes to sustain life on our planet is a proper stance at this stage of the evidence. The more we learn, the more it seems that the convergence of all the factors we enjoy on Earth is rare rather than commonplace. Consider well all that God and nature—sustained by God—have done so that you and I can exist. Be amazed; be very amazed!

[Salvation]

Video

[Salvation]

Monsignor Pope Ping!

[Blood of Tyrants]

After that they have to explain hoe non-living molecules became living things and how a cell evolved when any part of its incredibly complex mechanism didn’t evolve simultaneously it would never have lived at all.

[Candor7]

Huzzah for Darwin? Ha!

[M Kehoe]

Hi guy.

Sorry to bother you. It looks like you have one too many “and”s in your tagline.

Hey, if my brother had a booger in his nose, I would tell him.

5.56mm

[Moonman62]

I’ve held the rare Earth view for a long time, for no other reason than that’s what the evidence suggests.

I also believe the probability that humans ever existing even on a relatively life friendly planet like Earth is also extremely small for the same reason.

[bray]

Axing questions like that will get you accused of being a heretic on FR.

[Moonman62]

Abiogenesis and evolution are by far the best explanations that we have.

As to whether they were slightly guided is another matter.

[HamiltonJay]

Unlike Karl Sagan’s now foolish extrapolation that there must be huge numbers of planets with intelligent life... the more we understand about our galaxy, let alone our universe, we are finding the variables that have made and make life possible here on earth are FAR FAR more numerous than his infamous claims.

Life probably exists elsewhere, but highly developed intelligent life? Very likely very very few and far between.

Hell, if you just look at 1 thing, that needed to happen to make us possible, and that was midochondria.. and how rare that even was... and without that, complex large life is impossible... you can begin to comprehend how many things, had to go ‘just so” for us to be here now... It isn’t simply, we are a rocky core planet, approximately so far from our sun...

The sheer number of astronomically small probabilities that all had to happen for us to be here, and routinely we are finding even more insanely small likelihood things happened that would have prevented us from being here had they not.. Point to life, at least complex life, being incredibly rare.

If I were to venture a guess, if and when, we ever do find something more than microbial life out there, it will likely be in a system and planet that looks very different from our own.

[Dilbert San Diego]

Then what about shows such as Star Trek, and how they found numerous class M planets in the galaxy? And those planets had humanoid populations who spoke English?

Just joking around here.........

Also, I’ve heard theories about how there could be life on planets which could survive extreme temperatures and not need oxygen for survival.

It makes one wonder if we will ever encounter alien life , if we will ever overcome the vast distances in intersteller space to be able to explore and learn answers to such questions.

[litehaus]

“The sheer number of astronomically small probabilities that all had to happen for us to be here, and routinely we are finding even more insanely small likelihood things happened that would have prevented us from being here had they not.. Point to life, at least complex life, being incredibly rare.”

And to think that the UNIVERSE we know may be only one of many?

Maybe it is possible WE exist in a —— Single Corpuscle circulating in the ‘bloodstream’ of a sleeping being we cannot conceive of?

[Alas Babylon!]

I agree with you, except to say we only have ONE planet with life on it to extrapolate from, so we only know about the requirements and variances about carbon-based life.

There could be a planet somewhere where extremely rare conditions to support, say, silicon-based life on it.

We just won't know unless and until we encounter different kids of life, if at all.

[Ransomed]

We only have one example of life so far, and it only exists in one place. So it seems to me any theories on how rare or plentiful life may be elsewhere are flawed, they operate from an example of one. If we find 20 other examples of life, and they all exist within the same parameters we do, then it starts to become more reasonable.

Freegards

[SolidRedState]

One other issue is the length of time. The universe is billions of years old, the earth, if we believe what we are told, has had life for mere millions of years.

There may be a time when other “Earths” can exist and there may have been times when other “Earths” exist.

And there will be a time, hopefully in the FAR DISTANT future, when Earth may not exist.

[alloysteel]

I have a great idea for terraforming a planet that is a near twin of earth, and is right here in out solar system.

Venus presently has a helllishly hot atmosphere, with clouds of carbon dioxide and sulfuric acid forming a heat trap that does not allow the accumulated heat to escape, or things to cool enough so the water vapor also in the atmosphere can condense and fall as rain.

Once that dense cloud cover of broken, the existing supply of water vapor can begin to work its magic and proceed to bring the surface temperatures back down to bearable levels. Seeding the clouds with huge quantities of calcium or magnesium oxide, to react with the sulfuric acid and a lesser extent with the carbon dioxide, should cause much of this atmospheric composition to fall to the surface as a powdery mineral, as sulfates or carbonates.

As the surface of the planet turns away from the sun, the now much more clear atmosphere may then radiate off the excess heat, and since there is a great heat differential, the loss of the excess heat should go quickly, getting down in the range of where the water molecules can condense and fall as rain, thus initiating the heat-regulation system that has worked so wonderfully well here on planet Earth.

This may well take several human generations, before the surface may be habitable without special protective domes, and may also include re-aiming some “dirty snowball” comets into the atmospheric cover of Venus, which are composed of ammonia, carbon dioxide and water all frozen into a hard mineral mass. Within a few centuries, Venus could be remade into a warmer version of earth, and effectively doubling the surface upon which humanity and other terrestrial species could survive and even thrive.

[Hebrews 11:6]

I highly recommend Dr. Hugh Ross's Improbable Planet.

[Blood of Tyrants]

There is a remote possibility that is true, but it would have to be life of a form not suitable for an earthlike planet.

[JDoutrider]

4L8r

[Lee N. Field]

It’s not a Star Trek universe, out there.

[PIF]

And we are still finding new galaxies not to mention the billions of stars in each - even if this clown is right, that only means conditions for our biological sort - humans, animals, fishes etc- that look as we expect. It does not preclude life based on a different biology.