Imagine we lived in a scientific society, without any religions or belief in God. Then we wouldn’t have alternate stories or a Bible to explain fundamental questions as the origin of the universe, or the solar system, or the earth, or the diversity and complexity of life. Then all people would accept that science has made great strides in solving these questions.
We still don’t know the detailed sequence of chemical synthesis or environment that led to the creation and development of primitive life, but given the diversity of environments and the the hundreds of millions of years involved, there were certainly enough environmental “labs” that made the creation of life possible.
Yet life did develop on earth, and lacking alternate stories, it seems to have developed naturally. Life would be expected to possibly develop in other watery planets in habitable zones around other stars. We may soon have evidence by detecting oxygen in other planetary atmospheres.
It now appears that most stars have planetary systems, and a few percent have planets in a habitable zone. With a given 10^22 stars in the universe, it would seem highly improbable that life did not originate on many planets, but we don’t know for certain. It may be that scientifically advanced civilizations may not be in our neighboring region.
Evolution has been highly successful in adapting life to many different conditions, and in creating successful ecosystems.
I attended the Mars Society 2017 Convention, fortunately held at UC Irvine this year. The question of the fundamental effect of discovering evidence of fossil life on Mars was partly looked at in the context of a religious outlook that life was unique to earth. It seems clear from Gale crater that the Curiosity Rover has been exploring that surface water was once present. Since Mars does not support much atmosphere, it’s not clear to me how long that water existed. Free water on Mars could have occurred 3.8 billion years ago when it also had an atmosphere. There is frozen water on Mars, and subsurface water.
Since I don’t think in terms of religion, the question in my mind was how important, and in which ways was it important, to search for life on Mars? And, is that sufficiently important to send men to Mars, or to colonize Mars?
I was mostly unaware of the goals of the Mars Society, run by Dr. Robert Zubrin, yet this was their 20th Convention. He and others gave several reasons to go to Mars, although the “Gold Rush” reason has not yet been discovered. UCI Astrophysicist and Science Fiction Author Greg Benford cited the US Western Frontier as a great motivator for development, and the need for a regular transport system to Mars to carry it out. Dr. Zubrin pointed out the inspiration that the Earth was not a limited resource for nations to fight over, but Mars gave it a new expansive frontier. He emphasized a program to give NASA direction, and going to Mars directly, without diversionary trial targets.
Space X pioneer Elon Musk has proposed reusable rockets to eventually make a Mars City with a million inhabitants. Since Mars is closest to Earth every two years, Zubrin proposes half year transits, with a year working on the Planet. Problems during the trip are weightlessness in space, radiation from solar storms, and crew psychology in confined quarters. Zubrin is upset at NASA for its measures in keeping the Mars free from Earth life contaminations in our rovers, and in human exploration. Since living Martian organisms seem unlikely, he has a good argument.
If we find evidence of life elsewhere, other than actual space men, will it matter to really religious people? I don’t think so. Many religious people believe for spiritual, social, and moral reasons. Some, however, believe in a literal interpretation of the Bible. Despite evidence of evolution, they still believe that God created all life in all of its complexity. Despite knowing how the universe evolved and how planets form, they still believe that God made them a few thousand years ago. Despite scientific agreement on climate change, they still believe that only God controls climate, which they think of as weather. If they don’t believe in the vast paleontological record on earth, why are they going to believe in a few bacterial fossils from Mars?
Let’s look at the various rarity of life possibilities, and their detectable possibilities, both on Mars and in nearby planetary systems.
If life is easily formed, we may detect fossil evidence on Mars, and will definitely see it on nearby planetary systems, and have a problem with how it took hundreds of millions of years for life to begin on Earth.
If life takes hundreds of millions of years to develop, we may or may not find it on Mars, but should find it on nearby planetary systems.
If life is rare in occurrence, we won’t find it on Mars, and we won’t find it on nearby planetary systems.
Currently living life on Mars is negated by high surface radiation not being shielded by a magnetic field, and little atmosphere with little oxygen. Caves may exist with less radiation and with frozen water.
It seems much more likely to detect exoplanets with life, unless life is very rare.
Putting all of these prejudices together, I don’t see it necessary to send men to Mars to look for life, although I back more Rover missions. It’s not clear that we need sample return missions. We can do many analyses with robotics, including microscopes. We already know much about Mars rock and soil chemical composition and sedimentary layers from rover expeditions.
As usual, I am not an expert in any of these fields on which I opine.
Physicist Enrico Fermi had a classic argument that once life advances, it will rapidly spread across the galaxy, at least in the billions of years that the Earth has been around. It is called “Where is Everybody?”
Some are motivated to use our possible uniqueness in the universe as an argument for the importance of protecting our planet and our life forms. Even if life is abundant in the universe, we still have unique forms of it, and unique ecosystems. But we should preserve our planet because we feel humane to all human life, and are educated about the amazing evolution and adaptations and ecosystems in our life forms.
I definitely think that settling Mars to save humanity, as Steven Hawking suggests, is the wrong approach. All of that effort can go to preserving life on Earth and working on a sustainable future.