Facts of the Matter
Search for life elsewhere drives scientists
Our intense interest in searching for life elsewhere in the universe is driven by what is perhaps the oldest question since mankind became sentient: Are we alone?
No one knows how, or exactly when, the first life appeared on Earth, but the earliest are bacteria dating back at least 3.5 billion years. They appeared a mere 430 million years after Earth solidified from its molten state.
This is a surprisingly short time for life to develop, but however it happened it did happen, and it may have happened other than on Earth.
If favorable conditions were present on Mars or Europa for sufficient time, life might have appeared there as well. We now know that the range of favorable conditions for life is much broader than previously thought.
Our current understanding of life and what is necessary for it to exist requires water, preferably as liquid but perhaps as ice.
Radiotelescopes continue to search in vain for an electronic message from ET, but it would not require the sophistication of intelligent life to enliven our curiosity about our own uniqueness.
Any solid evidence of life, bacteria, ancient or otherwise, outside Earth would be enough to elicit a resounding "yes" to The Question and cause us to intensify our search for life in other places outside mother Earth.
There is still no general agreement that Mars has liquid water, so barring global disaster, homo sapiens will go to Mars to look for water, but also for fossils or living organisms. The first manned missions to Mars will undoubtedly happen in the next two decades.
Robotic instruments are cheaper than astronauts and risk no human life, but robots cannot collect fossils, and cannot process information beyond their programmed logic. That is why there are no robotic geologists nor robotic brain surgeons.
If the discovery of water would be an exciting scientific discovery, the discovery of any evidence of life on Mars, ancient of otherwise, would be one of the most significant events in human history.
For one thing we would want to know how like us they are.
If we fail to find evidence of life then the mystery will continue and the need to know will be even stronger.
It will not prove that life does not exist elsewhere. The absence of evidence is not evidence and cannot prove something to be true. It is a logical fallacy to think that a supposition is true only because it has not been proven false or that it is false only because it has not been proven true.
Some of us may not care one way or the other whether we are alone, but the answer could have wide-ranging social effects.
Our lives are inexorably intertwined with bacteria. They cause disease to be sure, but also provide numerous benefits both in and out of our bodies.
Recent findings suggest that some of what appear to be useless genes may actually be bacterial genes embedded in our DNA that produce bacteria within us as part of the genetic blueprint from which are bodies are assembled.
Bacteria have not outlived their usefulness, and they hold many more surprises for us about our relationship with them whether or not we find them on Mars.
Richard Brill, professor of science at Honolulu Community College, teaches earth and physical science and investigates life and the universe. E-mail questions and comments to firstname.lastname@example.org