Unlikely Alone—Part 1

Ever since we humans came to understand that those points of light in the night sky are stars like our sun, many of us have wondered if some of those stars host planets that may contain some form of life. Are we alone in this grand universe? Is it possible that life may be thriving on other worlds out there, just as it does on our precious little planet?

These questions have lingered in people’s minds for millennia, but the means to answer them have eluded us until recently. The pursuit of this inquiry has not been encouraged by our religious institutions—particularly those that teach that human beings are special creatures molded by God, and thus at the center of the universe. This perspective remains convinced that Earth is unique and at the center of the universe. Despite that dogmatic view, many people have wondered if we may not be alone and maybe not that exceptional.

The issue has received increasing scientific attention in the last few decades. A number of projects are actively exploring the matter and are gradually leading us toward an answer. The possibility of life existing elsewhere has recently been given a major boost by two different areas of scientific research: (1) in astronomy, by the discovery of numerous planets around nearby stars by NASA and (2) in biology, by the discovery of several bizarre life-forms right here on our planet.

NASA's Kepler mission has now identified hundreds of planets around close-by stars—evidence we didn't have just a few years ago. Astronomers have for some time expected planets to be common, but until their existence could be demonstrated, we didn't really know. Now we do. The result: it is highly likely that there are billions of planets out there; just in our galaxy alone! So the likelihood of extraterrestrial life is definitely boosted—given that the more planets there are, the more chance that life could have formed on some of them.

The second recent finding—the discovery of Earthly forms of life we once did not think possible—also increases the likelihood of extraterrestrial life. Researchers have found life in forms and locations that surprise us: in rocks far underground where no light ever shines, at high temperatures we once thought would cook any critter, and in very unfriendly locations such as in strong acid environments that would dissolve the skin of any human. If life is this tough, we've had to revise our estimates of the kinds of harsh environments in which life could thrive on other worlds.

So we now have greater expectations of finding life out there. Mars may have once been warm and wet, and thus conducive to life. Jupiter's moon Europa and Saturn's moon Enceladus have scientists excited about the possibility of life there. SETI (Search for Extraterrestrial Intelligence) telescopes constantly scan the skies, looking for electromagnetic signals that alien intelligent species may have transmitted into space. (We ourselves do it all the time—not intentionally as a signal, but via our constant radio and TV transmissions that escape into space.)

With these findings, our level of anticipation of life elsewhere has skyrocketed. We're gaining confidence that we may not be alone. There is still no direct evidence for life elsewhere, but its likelihood is greater, as our understanding of  conditions out there increase.

More on extraterrestrial life next time…