Are We Martians?
This is one of many questions raised in the book Probability 1: Why There Must Be Intelligent Life in the Universe. Author Amire Aczel, Ph.D., applies his background in mathematics, science, and statistical analysis to build a parallel between the evolution of life on earth and the possibility of such evolution on other planets in the vast, endless universe.
Do I recommend this book as a good read? No, unless you are huge into mathematical equations, quantum and chaos theory, genetic code dissection, probability distributions, and the such. You know, regular chit-chat over a cup of coffee. But buried in all the statistics, hypothesis, and theory is information well worth knowing, so I am going to share just some of it with you here. Much of what he offers is eye-opening and moves us to think outside the quadrilateral parallelogram (box).
The Panspermia Hypothesis
The panspermia hypothesis is a good example. The theory is that life-bearing spores from Earth (or any other planets with life) are continually ejected into space where they drift randomly to eventually land on other planets, and if some of those planets have the right life-sustaining mix, could provide the DNA catalyst for the formation of life.
So then, the question begs to be asked—is that how life on earth came about? In 1984 a potato-size meteorite (ALH84001, for those who care) was discovered in an ice field in Antarctica.
The source of life on Earth?
Scientists studying the meteorite found that it originated from Mars and was launched into space when an asteroid collided with Mars some 15 million years ago. Their analysis indicated the rock was near the Martian surface 3.6 billion years ago when underground water may have still sustained life. They performed tests and discovered the rock contained organic molecules: Martian life? And if so, could this have been where the DNA originated that eventually developed into Homo Sapiens?
Sorry to say, but probably not. Advances in radiocarbon dating and further study resulted in a general consensus by the scientific community that the organisms were of earthly origin, formed during its millions of years here on Earth. But this does not close the door on such a possibility; that a meteorite or free-floating spore could have deposited on earth, from Mars or otherwise, and have provided our DNA kick-start.
So what does it take to provide the right stew pot for life’s creation?
Aczel gets into this at length as it is an integral part of his analysis. Life is so delicate that the recipe needs to be just perfect to exist—from the minuteness of an electron’s mass to the position the planet is in relation to the sun. This last ingredient, called The Goldilocks Zone, provides the initial foundation for success. The planet must be the right distance from the sun; in other words not too hot and not too cold, but just right. And we probably would not be here if Earth’s sister planet, Theia, had not impacted with it and created the moon. Yes, that’s right. There were two ‘earths’ in the same orbit around the sun. Eventually they collided forming the earth as we know it, and ejecting enough rock into gravitational orbit that the moon formed from the debris. It was the gravitational movement of the moon around Earth that eventually put our planet into the rotation we now appreciate as 24-hour days, and through the collision with Theia, Earth began rotating on its axis, which we now appreciate as seasons. Without these, perhaps only a quarter of the earth’s surface would be habitable. And would life have been started or sustainable under those conditions?
Many other factors also must come into play. For instance, even if life started on Earth or another planet, it would need billions of years to develop into an intelligent species. Think back on the history of our planet alone and the volatility it has witnessed. Dinosaurs were the dominant species until an asteroid crashed to earth, creating an environment they could not survive. And that was a small asteroid, in terms of size, to what is flying around out there. At one point it was thought the asteroid known as 1997 SF11 would come close enough to Earth in the year 2028 that it could collide and destroy the world. Luckily, further calculations have changed that prognosis. But this brings into play another important ingredient to providing an environment of long-term sustainability of life. If Jupiter and Saturn were not as large as they are (you could fit 744 earths in Saturn, and 1,300 in Jupiter), we would probably not exist. They stand as guardians of Earth, their huge gravitational pulls drawing any and (just about) all meteoroids and asteroids to their surfaces, protecting the billions of years of life’s evolution on Earth. And so, existence of intelligent life, given the billions of years to develop, would need such planets in close orbit to the Goldilocks planet to provide that same protection. For Aczel determines that it is inevitable that intelligence life will be the result, given enough time to develop.
Could such a complex recipe exist out there? Aczel estimates there is a one in a trillion chance that life would evolve on a planet that fits the habitable zone formula. So very remote, right? But our galaxy alone has about 300 billion stars and it is estimated that there are 100 billion galaxies in the universe. Aczel shows through mathematical formula and statistical analysis that since the probability of the existence of life is not zero, it therefore must exist on at least one other planet in the universe. At what level of development or intelligence is unknown, but (my thought here) with the number of documented visitations by extraterrestrials to our planet, I think we already have our proof that intelligence well beyond our own exists out there.
Probability 1 was written in 1998. Currently there are over 16 exoplanets identified that are of the right size, composition, mass, and distance from their suns to be considered habitable. And the search goes on. As recently as November 15, 2017 the scientific community became excited over the discovery of Ross 128 b, an exoplanet in the Virgo constellation that appears to meet all of the criteria of supporting life. And these are just the planets we can see now with our limited technology. What else is out there?
The images below are the planets discovered by the Kepler and Trappist telescopes. Both show the planets and suns where life could exist or have the potential for habitation and colonization.