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Probability of Extraterrestial Life

Updated on September 4, 2015
Space telescopes can be used for searching for sentient extraterrestrial life.
Space telescopes can be used for searching for sentient extraterrestrial life. | Source

Estraterrestrial Life Probability Equations

The Rare Earth Equation Vs. The Drake Equation

The Rare Earth Equation and the Drake Equation are opposed in their findings. The first considers all the possible variables (continually adding more) required for life to exist in our solar system on earth. These variables include approximately 34-37 variables or more, all held within specific range values that, all variables together, permit life to exist on Earth.

This equation is reportedly used to support the Intelligent Design position over the Big Bang stance on creation of life and the universe(s).

The Drake Equation results in findings that suggest a sizable number of possible Earth-like planets with humanoid populations.

Drake and Life In the Milky Way

The Drake Equation examines the probability of life in Milky Way Galaxy from another direction, beginning with the total number of stars in the galaxy and whittling it down by percentages presented by 8 or so variables (please see Links). This results in a number around 10,000 for the possibile earth-like planets in Milky Way Galaxy that potentially support humans or humanoid life.

While the Rare Earth Equation has reportedly replaced the Drake Equation in authority and accuracy, even more variables might be included month by month, making life on Earth even more rare mathematically.

There may still be life in other galaxies or universes, but so far away that we would never meet without the Transwarp Drive of Star Trek creation. It is all possible, those not probable in this century.

We do have clearsteel from Star Trek creation, but it is not totally transparent. We can move a cluster of eight photons around a laboratory, teleporation style (2015). We do have artificial skin for burn victims, just not yet available in a spray can.

"I see an alien life form."

"Do I really see you?" Aliens are alien to each other.
"Do I really see you?" Aliens are alien to each other.

Ward and Brownlee : The Rare Earth, Opposed to the Drake Equation

A Rare Earth Considered in Another Equation

"Rare Earth" Equation Variables:

N* = stars in the Milky Way galaxy,

fp = fraction of stars likely to have planets,

fpm = fraction of metal-rich planets likely to exist,

ne = planets in a star's habitable zone,

ng = stars in a Galactic habitable zone,

fi = fraction of habitable planets where life arises,

fc = fraction of planets with life where complex life arises,

fl = percentage of a lifetime of a planet that is marked by the presence of complex life,

fm = fraction of planets with a large satellite (moon),

fj = fraction of planetary systems with Jupiter-sized planets,

fme = fraction of planets with critically low mass-extinction events

Apparently, the degree of tilt of each of the several axes of Sol and all the planets and moons in this solar system affect the Earth and its ability to sustain life. The size of all the moons of all the planets play a part as well.

There are so many elements to hold stable in order to sustain life on Earth!

Robot and NASA Astronaut
Robot and NASA Astronaut | Source

Background and Static

I do not, of my own knowledge, know if we will ever discover with certainty whether there is humanoid or at least mammalian life elsewhere in the Universe(s). Maybe there is, maybe there is not; I would be happy either way. I think it may be too complex a problem to solve, but a very interesting one. I've written Hubs on UFOs and angels and such, so Hubbers and readers know that I am not against the notion.

While it is fascinating to consider in the realms of both science fiction and science fact, the process of the contemplation of the notion of extraterrestrial life is attacked and disrupted from outside by lobbyist factions. There is a politic of other-worldliness at work.

These factions include those that believe that extraterrestrial life is nonsense just on general principles (a pipe dream) and that the people thinking about it should get a job.

Private Companies May Contact Other Civilizations

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SpaceX is a private aerospace company involved in space business and exploration.
SpaceX is a private aerospace company involved in space business and exploration.
SpaceX is a private aerospace company involved in space business and exploration. | Source

The Politics of Life in the Universe

Other factions:

  • There are those that discard the notion of other life in space out-of-hand, because their religion prevents such a phenomenon to exist. Some spiritual leaders teach that UFOs and space aliens are demons and the fallen angels of the Creation - the 1/3 that fell with satan in the Bible. My own pastor employs a staff of scientists and they advise that there may be other dimensions besides our real-time world and that they may overlap and beings from elsewhere may appear here and that perhaps this is what we have come to explain as heaven and hell, among other places. The change from life on Earth to heaven is to take place in a twinkling of an eye, suggesting teleportation if this multiple-dimension notion is real.

What is certain is that we cannot break the speed of light (and get to other places "out there") by going faster. We can get closer to it by ½ of ½ of ½ the speed and distance remaining and so on, but never get there while governed by the laws of physics in this dimension, so far. Photons were transported across a lab in 1996, but they were slightly different on their arrival on the other side. We would be somehow rearranged if we could travel in this manner.

One argument against other life in humanoid form is that Christ died for humans and not for aliens, so they can't go to heaven. If they exist, maybe they don't need to get to heaven in that way. After all, Christ did not die for the angels and they are reportedly there and in the air. Other religions and faiths have their own issues with this. So, to settle this in my own mind, I say that if alien humanoids do exist, then perhaps they do not have the same relationship with God that any/some humans do and they do not need to be required to have it.

CS Lewis wrote The Space Trilogy about this type of thing and you can read about it in some of my reviews at Classic Literature at:

Dark Matter Vizualization

Is the Cost Too High?

Political cartoons. From the famous Gropper Estate.
Political cartoons. From the famous Gropper Estate.

More Opinions and Pressures

  • One group of human beings hopes that an outside force, such as an alien invasion or the threat of such invasion, will pull the governments of the world into some sort of unity. This has given rise to conspiracy theories, including one that the UFO Phenomenon was invented to produce such unity after WWII.
  • There are others who feel aliens are most certainly superior to human beings and either can help us or annihilate us. Many novels and movies fall on both sides of this question.
  • Another group of human minds think that since the Universe is so grand and so big, there simply must be other life "out there." Many of them think about humanoid life being the life that they expect to find. However, single celled life is more probable, like bacteria found on Mars in the mid-2010s.

"Because the huge Universe exists, there must be something in it" is akin to saying that an empty refrigerator is so big that it must contain some sort of food.

As far as the universe goes, perhaps there is a finite amount of atomic matter in it and Earth has used most of it up on humans and waste. Or not. Considering the refrigerator, perhaps the filler of the refrigerator was too tired to go to the Galactic Grocery.

Or consider this statement: A man has two legs, therefore he should walk. -- Not if he is paralyzed.

We have additional factors to consider besides the size of the Universe(s) in order to determine whether sentient life exists elsewhere than on our planet. Much of Outer Space is a vacuum with absolutely nothing in it.

There are those whom we may call Star Gate Believers, those who feel that life on Earth was put here by visiting aliens of an Egyptian ancestry. There is one such group that believes a giant UFO is buried under the Pyramid of Gizeh, ready for an escape by the chosen few (they say from England) at the end of the world. Star Trek: The Next Generation presented this same type of message, except the umbrella species, the Dominion, was made up of bald shape-shifters that lived joined together as an ocean. Another Star Trek episode presented evidence that all humanoid races were seeded by another umbrella race. Many people believe that idea.

Some people think mankind lived on Mars first, then man's waste and global warming ruined that planet and seeds of man were sent to Earth, the next habitable member of our solar system.

Related ideas emerge every day.


NASA, SETI, Private Research

I feel that it's legitimate for scientists, SETI, The Mars Society and such otherr organizations to actively continue to search for extraterrestrial life and to plan communities on the Moon and Mars, unhindered by factions. As long as funding is available - especially private funding - I think we should pursue the equations and the research to their natural conclusions. Tax dollars should likely be used for more "down to Earth" problems.

To me, this is a better expenditure than the $9,000,000,000 USA sent to South America some years ago to look for "new insects."

It may prove that we have lttle chance of meeting the other life out there in the Universe(s), at least in this century.

Part of the desire to find extraterrestrial life is sometimes a wish find a point of origin and/or to find another system in which to succeed, because life on Earth is too frustrating, painful, or unexplained at times. It's the running-from-problems sort of thing for some folk, buit not for all. Some would relish the chance to meet more humans and humanoids - to exlpore new worlds and new civilizations with greater hope for the future.

© 2008 Patty Inglish


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    • profile image

      aktmjcor 5 years ago

      I was raised a good catholic boy. Most of my life i believed there was no other life or even a chance of life. God made us and earth and thats it. How sad that it took so many years just to change my thinking. I wonder how many kids out there think the same thing.

    • peacock413 profile image

      peacock413 7 years ago

      Hey im am very interested in the idea of life on other planets!! im writing a sci-fi blog check it out :)

    • profile image

      Joanna 7 years ago

      I am studing space. I need to know if there is life on other planets

    • Patty Inglish, MS profile image

      Patty Inglish 7 years ago from North America

      Hey thanks for that - bacteria could indeed be everywhere.

      Sandra - you could go up yet, in new missions to Luna and Mars through 2040! And we know astronauts really can fly into their 80s, with proper bone and blood pressure monitoring. :)

    • MikeNV profile image

      MikeNV 7 years ago from Henderson, NV

      "Earth-like planets are still too small to detect so we haven't found any," Lineweaver said. "However, the rapidity with which life arose on Earth suggests that more than 10 percent of terrestrial planets have life. We're not talking about trees and animals; we're talking about any kind of life. The smart money is on the idea that bacteria [are] all over the Universe. What it has evolved into is anybody's guess." -- Discovery News

    • profile image

      sandra rinck 9 years ago

      I think about it sometimes. Your so lucky, you got offered a chance to work at NASA, I only dream about being able to go to space, just for a second, just to look, just to see it with my own eyes, to feel you know?

      Your so lucky and blessed Patty.

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      Interesting thoughts. I've been reading a lot about mass created out of energy in space -- subatomic particles, but only for an instant and then changing right away back into energy. And how many of the stars and planets and such that we record with telescopes are actually no longer in existence, but we are only now receiving their light-records? It seems to take a huge amount of energy to force subatomic particles into atoms, let alone molecules into intelligent life forms. How long must that take - how much energy actually - unimaginable.  

    • profile image

      Gems4friends 9 years ago from Spokane, WA

      "One argument against other life in humanoid form is that Christ died for humans and not for aliens, so they can't go to heaven."Well, quite obviously Christ also appeared to those aliens and died for them, as well. :) Since Christ is part of an infinite God this is trivial top accomplish. No, I'm not being serious here. As far as life on other planets, well, I think it's logical to believe that it's inevitable. Based on where life occurs on this planet, from ice fields to rocks beneath the ocean, to nuclear reactor coolant pools how could it be otherwise? With billions of stars just in this galaxy, and billions of galaxies there are probably billions of planets with life. Now, if you want to talk about complex life, much less human life... Let's face it, you're not going to find bunny rabbits surviving in reactor coolant pools. But with a billion or two years of evolution? It might be interesting. Human life? Oh, I'd say that's extremely unlikely. Intelligent life? Given the age of the universe, the number of stars, the fact of planets around those stars (and we can't yet detect Earth size planets,) and the very high probability that some portion of those planets are conducive to developing complex life, I think other intelligent life is inevitable. How common is it? Now that's the tough, even unanswerable, question. It's probably uncommon enough that we're unlikely to encounter it in any of our lifetimes. Alternately, even if intelligent life is relatively common, and faster-than-light travel is totally impossible, we'll still never meet them. And then again, we might, maybe, just live in a a relatively unpopulated region of the galaxy. How likely is it for any intelligent anywhere near our stage of development? I think that's very unlikely. Just a 1% difference in development speed puts them at least 10,000 years ahead or behind us. Most of the planets out there that are capable of supporting life will be either younger or older than the Earth. So even with exactly the same conditions and development speed you'll see radically different tech levels. Where will WE be in 10k years? What would we think if we met those people? And why should they necessarily be peaceful? Great hub.

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      I do not mean to load you down! Just, if you should be happing across these things, please share. No pressure. :)

    • Peter M. Lopez profile image

      Peter M. Lopez 9 years ago from Sweetwater, TX

      I'll get back to you on that, it's a lot of homework, but I'll look into it.

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      How about Ezekiel's Wheel-within-a wheel? Some think that is other life forms or other of God's beings. Angels are surely not men and women... There are indeed, other beings.

      Peter, once in a sermon at a church I visited, we were told that God mad three different versions of Earth and mankind and we are the third one. I have never been able to to find that in scripture translation I have read.

      What does the Hebrew alphabet itself have to say about this Peter?

      What I like is that you said, "I kinda hope we do..." That's honest, rather than use the distracting falacies, arroganace or "must be." HOPE is good.

      The religious argument? That's imo based on a fear that there really is no God or a fear of threat from beings that will usurp mankind's life, benefits, place with God, whatever. The argument [a falacy] runs that Christ is only for humans, so there cannot be other humandoids, because they would all go to Hell. Wrong headed and illogical. If they exist, they need not have ever needed reconciliation with the Father through Christ. See what I mean?

      Now how about some Hebrew alphabet word pictures - are there any relative to lights in the sky, wheel-in-a-wheel, etc.?

      And my favorite question - Who were the people in Nod that Adam's family mated with? Adam's family were the only humans so far before that?

    • Peter M. Lopez profile image

      Peter M. Lopez 9 years ago from Sweetwater, TX

      And the Milky Way is just one of billions upon billions of galaxies. As best I can tell, the Bible is silent on the matter, so maybe one day well will meet alien brethren...I kinda' hope we do.

      I remain a student of theology, religion, etc., but I still cannot quite grasp the religious objection to this possibility. My God is big enough to have created countless life-bearing worlds, whether He did or not we cannot really say. Great hub.

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      gecko-friend -- It does not neeed to be depressing. There is nothing wrong with HOPE depite the trends of the brain! That is different from logic. We will be geeks together! :) geek 1 :) geek 2 Yes, Klingon differences very goofy.

      Gary - Thanks for your comments and stopping by.

    • thegecko profile image

      Warren Samu 9 years ago from San Diego, CA


      Excellent response, if not rather depressing.

      And I do remember the seed episode. The Star Trek's attempt to explain why so many humanoids look alike? I guess I didn't make the Dominion connection. Maybe I'll revisit that someday.

      Better than when they tried to explain why Klingons likk different post the original series. Now I'm feeling like a real geek :P

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      The brain wants to see continuation of patterns and oiterations throughout the universe. Is that turns out to be true, I will accept it. But it is not a necessary truth.

      The universe is mostly vacuum, energy traveling through it, with dark and "regular" matter. Refreigerator, bread box, empty warehouse, hollow planet, universe whether limitless or a figure-eight interloop Mobius; they are all similar -spaces that do not logically necessitate content.

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      Haha, funny one -- The episode about seeding the planets was on Star Trek the NExt Generation and from that, the hologram of the to-be-named-in-future "Dominion" race was placed into DS9.

    • thegecko profile image

      Warren Samu 9 years ago from San Diego, CA

      I hope my avatar doesn't suggest any bias to anyone :)

    • thegecko profile image

      Warren Samu 9 years ago from San Diego, CA

      Very interesting discussion!

      Patty, I must point out however the fallacy in comparing an empty refrigerator to the universe. These two things do not remotely resemble each other. We also know that the universe is far from empty. That does not mean of course that because life exists in one part of the universe, it exists somewhere else.

      I would like to say though that science requires a certain amount of repetition, of consistent patterns, even if those patterns fall in the line of complete randomness every time. If we study the universe in terms of patterns, that it happens like this here, so we will presume that it works that way over there (not that this will prove to be the best way to analyze the stars), then why not our unique formation being found somewhere else? If the universe (as far as we know) consists of the same materials everywhere, then it would seem that the same conditions could be replicated in so vast and ever changing a space. I do not necessarily agree with this, as I posted above, but if we're going to use the current methods to study the cosmos, might as well go all the way!

      Oh, btw, the Dominion is from DS9 ;)

    • debrakcarey profile image

      debrakcarey 9 years ago from West Plains, Missouri

      Hello, I enjoyed this blog and would like to suggest a couple of books that may interest you. "The Hidden Face of God"  and "The Science of God" by Gerald L. Schroeder. I believe in the Big Bang AND in Intelligent Design. These books will explain why I feel that the big bang theory and intelligent design are not mutually exclusive theories. As far as there being intelligent life outside our solar system, I have to think, why not? My faith in God is based on a search for truth in all fields of study, not just religion. Again, thank you for this post. Debi

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      Thank you all for a wide range of comments.

      I'm not emotionally invested in whether there is sentient life elsewhere or not - if there is - Great! Fantastic! Fun! Truth! If there is not, that's fine. Great! Fantastic! Truth!

      Arrogance and "must be" are irrelevant, because:

      It is a classic scientific error (one manditorily included in "the possible errors" in studies and mentioned directly or indirectly) - a result of human brain's function and structure - to see connections or to manufacture them from connecting dots.

      Yet, the relAtivity comments of thegecko are probably the best.

      Arrogance has nothing to do with it -- Just because something is big does not mean anything is in it. If there is, then we must all accept that fact and be glad.

      As Garry says, TIME WILL TELL.. And I will be happy either way. Life is a gift - ALL life.


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    • Garry Nelson profile image

      Garry Nelson 9 years ago from Hawaii


      If we find life from the lowest mud puddle to the highest mountiain. Why would it stop? It feels sort of arogant to think that we are all there is. Not to worry, time will tell.

      Garry Nelson

    • thegecko profile image

      Warren Samu 9 years ago from San Diego, CA

      You approach the topics from several directions... but also consider this (based on my limited knowledge of astronomy):

      Scientists currently can only use the tools and environments around them to analyze and ponder the rest of the universe. We use our own distance from the sun as a measuring stick, our understanding of gravity to assume the location of unseen planets, our study of different stars to create a progressional timeline of space formations. However, we can never actually test many of these principles, measure the actual distances, watch the lifepsan of a star, see if planets and other objects really do exist beyond our vision.

      Humans remain trapped in relativity. Just like physics can operate differently off Earth than on Earth, it could very well function differently in different parts of the galaxy, and universe. Just because life on Earth requires certain complex combinations of location, substances, etc. does not mean that there cannot be life that does not require water, or air, or sunlight.

      Humans can only really test the limited position around them. Astronomy constantly changes with our expanding knowledge of just the small things we can test and see, just like Pluto is no longer a planet. We really do not know what is or can be out there, so how can we assume to know the probability of other life in any form? How could we ever test it?

      So, while we live in our powerlessness, I like to think that there must be something else out there :)

    • Francis Moran profile image

      Francis Moran 9 years ago from Paramount, CA

      again another very interesting and mind bending hub!

      i believe that life does exist outside earth. In fact, some meteorites have been found to contain fossilized microscopic life forms! Well as for more sentient types... this still remains to be seen and discovered. A definitely amazing day - imagine, First Contact!

      another very great hub!

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      haha. That's good!

    • About-The-Home profile image

      About-The-Home 9 years ago

      I forgot to add "...but still they came"!!

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      Fascinating and sincere comments like recent ones of yours above are delightful!

      I love the song lyrics, too.


    • About-The-Home profile image

      About-The-Home 9 years ago

      Love this hub, although most of it is light-years above my head!!!

      I enjoyed looking at the pictures (that's my level).

      All I know is "the chances of anything coming from Mars are a million to one"

      (It's a song!!!)

    • VioletSun profile image

      VioletSun 9 years ago from Oregon/ Name: Marie

      As I read your hub, I am thinking, wow, besides the possibility of earning income with Hubpages, one learns so much in this community, thanks for this hub! I believe in possibilities because in life, I have encountered experiences and occasionally with "proof", at least for those close to me, that this universe is full of surprises and limitless possiblities, so who knows, maye we won't find life in another planet but they will find us. :)

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      Thank for the kind comments, Abhinyaa. I'm glad you assured your child of possibilitites. As a sci-fi film told us ..."There are always possibiltiies..." It will be your child's generation perhaps that reaches closest to the final answer!

    • profile image

      Abhinaya 9 years ago

      Your knowledge on astronomy is amazing.My kid keeps asking me if aliens really exist.I have no answer.I keep telling them since the astronomers have found frozen ice may be there is a possibility of life on Mars.I really don't know.

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      That is heart-achingly true, Zsuzsy. Once we found out that there may be anly a little bacteria or such on Mars now, The Martian Chronicles was not so "magic" a story.

      But if life can develop at minus 180 degress F in ice, as in the article in the links, then we have a new source for intrigue and wonder. :)

    • Zsuzsy Bee profile image

      Zsuzsy Bee 9 years ago from Ontario/Canada

      I just love the thought, the mystery; is there or isn't there. Once we find out for sure, that intrigue will be gone and then we will have found the sky's limit. It would be the same as if someone were to tell there is no Santa.....

      great hub regards Zsuzsy

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      Hello bohica, thanks for the information. The story was in our local newspaper, The Columbus Dspatch, in the late 1990s, about 1998 or 1999. The article was a short interview with NASA personnel and displayed pictures of three men in their 80s and the son of one of them, who reported that he was in his mid-50s. It was reported as an experiemental training program to investgate aging and space travel/living, using older adults, especially parents and children.

      I could never find anything written about it again and can't find anything about it now. My thought is that it must have been un-funded or an early failure, since you have never heard of it.

    • bohica profile image

      bohica 9 years ago

      As an ex-NASA type, the oldest astronaut that I know of was John Glenn. I have never heard of an age group that you suggest.

    • Patty Inglish, MS profile image

      Patty Inglish 9 years ago from North America

      Go for it! I would not have gone up in the 1970s when somehow the marines and some engineering program tried to recuit me for space engineer training, but I might go up now. I don't like the confining suits, though, especially that body stocking that goes even up over the head. I'd have to shave my haed to be comfortable, but that's ok. New hairdo later.

      To see how long we can continue to fly in space, NASA did an experimental space flight program with 80-year-olds and there 50 to 60 year old children. I can't find the info on it anymore. I wonder how they got along?

    • Lissie profile image

      Elisabeth Sowerbutts 9 years ago from New Zealand

      To me its the ultimate trip - really getting out to the stars! I intend to get to outerspace befoer I die - and I don't just mean the commercial Virgin flights which are sub-orbital but real outerspace - I probably have another 40 years before its too late for me!