SETI Reset—Part 2

In the last post I began to describe a few possible reasons why our Search for Extraterrestrial Intelligence (SETI) has as yet not found any signals arriving from outer space. Here are a few more suggestions I offer.

(2) Other alien civilizations may not have chosen to pursue a similar technological path as we have. Our technology too often has led to weapons that harm living beings. I can conceive of a civilization deciding to have taken a more sensible and peaceful approach and thus avoided technology’s harmful side effects, by avoiding much of our problematic technical inventions, such as the many types of weapons we’ve created. Would it not have been possible for Earth’s humans to have decided to put its energies into a spiritual society, rather than a high-tech and dangerous existence?

(3) Life may indeed be common out there, but the chances of it progressing beyond a single-celled state to a multi-cellular, more complex phase, may be quite low. Life on this planet stayed at a microbial state for about three billion years, before favorable conditions evolved to allow it to grow large enough to build things like cars and computers. Those propitious conditions were not inevitable. Life on Earth could still today easily be simple, single-celled critters, waiting patiently to grow more complex. 

(4) It took 4.5 billion years for “intelligent” life to evolve on Earth, so there's a low probability that life elsewhere (at the present) is at a similar stage of technological development to us. They may not reach that stage for a few billion years yet, or have long ago passed through it. I say “pass through it,” because an argument can be made that if life is to survive in the long term, it may have to get past dabbling with hazardous technological toys.

And finally, (5) Life anywhere in the universe may be doomed to evolve into a technological stage, after which it inevitably extinguishes itself. We on Earth seem to be headed towards what is often called an “omega point”—a time where we dramatically transform from civilization’s chaotic and exponential path, towards a sustainable way. It may be that that omega point could be the arrival of a completely different kind of intelligent life on Earth… if we survive to that time.

So the search for SETI will go on. We are curious creatures, and we want to know if there are others like us out there. It appears increasingly likely that extraterrestrial life might well exist, given our recent discoveries of extrasolar planets and Earth-bound extremophile-kinds of life. If the discovery of life in the vastness of the universe comes about, it would be an incredible discovery.

We cannot yet travel to the many distant worlds and directly observe life there... and maybe we never will—given the immense distances. So we continue look out there, building receivers to apprehend any EM signals flying through our region of space; which could prove that we are not alone. But is the presence of an “intelligent” species out there really going to be detected only by our reception of a technological signal they emit? Could there be other kinds of contact that we’ve not yet imagined? We'd best keep our minds open.

Next time I will describe yet another, rather weird possibility, for reconsidering the SETI issue… that we may already have been contacted and absorbed into a super intelligent civilization’s domain.

Alien Intelligence

The search is fully on for signs of intelligent life on planets other than Earth. Humans have long pondered whether or not life arose elsewhere—and in particular, if it could be intelligent life. Up until the last couple of decades, this conjecture was little more than idle speculation. But now we have telescopes that have discovered thousands of planets circling nearby stars—some of those planets might harbor life. Additionally, our definition of the extreme conditions under which life can survive has greatly expanded, so we can now expect to see life surviving under fierce conditions that we once thought were impossible. More and more, it seems that the discovery of extraterrestrial life is more a matter of “when,” not “if.”

Very recently there's been yet another finding in this arena—right here on Earth—of a new type of intelligence that was under our noses, but was never before recognized. This finding is very similar to recent discoveries of terrestrial lifeforms—dubbed “extremophiles”—that thrive in conditions we once considered to be too hostile to allow life. The new discovery is a species of ocean critters called ctenophores (pronounced ten-o-fors) that are intelligent creatures who evolved their brains and nervous systems in a very different manner from the rest of Earth's species. They are some kind of alien.

From the earliest understood forms of Earth life, all the way up to us humans, the progression of nervous systems from primitive cells to the human brain have followed what we came to believe was a singular path. All life's nervous systems (so we have believed) genetically evolved to employ common neural messengers, such as serotonin, dopamine, and nitric oxide. This mechanism is the same, from nematodes to ants to humans. We've all evolved our nervous systems in the same fashion.

A Russian scientist (Leonid Moroz) who emigrated from his native land to the US two decades ago, insisted upon looking more deeply into the qualities of ctenophores. These critters had been identified and cataloged for a long time—and were considered to be a close cousin of jellyfish. When Moroz captured a few of these critters and began examining them, however, he found that, although they had evolved muscles and a nervous system like other creatures, they took an entirely different route from all other life forms.

Ctenophores are a very ancient life-form. They display an example of what is called convergence: life evolving into similar-looking critters, but doing so by following a different evolutionary path. For example, eyes have independently evolved many times, following parallel but quite different evolutionary paths. Porpoises and sharks are very similar creatures, but evolved through completely different paths. One is a mammal, the other is a fish. In the case of the porpoise and shark, we find very different critters which arrived at the same solution, because—although they started at different beginning points—they each had to solve the same problems: swimming.

What is fascinating about ctenophores is that, had their singular evolutionary route been favored by nature, life-forms on Earth today would be very different. Life would likely have eventually still evolved nervous systems and sophisticated brains, but they'd be housed in quite different kinds of animals. There would be no humans, as we know them.

This discovery has relevance to our search for extraterrestrial life. Just as the existence of extremophiles has caused us to open our minds to other kinds of life elsewhere, ctenophores seem to be advising us to open our minds even more, to understanding that intelligence may have evolved in alien ways that we have yet to understand, and to be on the lookout for some strange possibilities. We can learn from aliens right here on Earth.

Stalwart Life

Over the last few decades scientists have discovered life thriving in environments that were once considered to be too hostile and barren. For example, dozens of miles under the sea surface, where it's inky black and noxious fumes vent from smoky fumeroles, organisms thrive in water as hot as 200^oF. Deep in underground mines (some 2 ½ miles down), far from the sun and its life-giving rays, microorganisms feed on minerals and soak up heat from radioactivity, in lieu of any photosynthetic processes. In extremely acidic water, near its boiling point (such as in Yellowstone National Park), other organisms prosper. Only a few decades ago scientists would have been convinced that life (as they then knew it) could not survive in such harsh environments.

These discoveries of life's robustness have forced biologists to revise the conditions under which they believe life could survive. The very definitions of what constitutes life and what life requires to take root and thrive have been dramatically amended.

A recent example of another unlikely site for life has been the discovery of robust creatures deep under the Antarctic ice shelves, far from sunlight, in a location that was expected to be dark, cold, and lifeless. After having drilled a half-mile deep hole through the ice shelf, 500 miles inland from the open ocean and that far from any sunlight, researchers found microbes and small fish—in a completely dark location. How did these critters get there? How do they survive? I won't go into the details here, but the scientists were dumbfounded, when they lowered an underwater robot and photographed creatures. It blew their minds.

These recent discoveries have caused scientists to revise their theories about what life requires to survive, as well as to recognize the new kinds of life they've found in these hostile environments. The requirements for life on Earth have been significantly broadened. Maybe life doesn't require water—once thought to be absolutely necessary. Maybe it doesn't require photosynthesis of the sun's energy—which most every life form must have. Maybe it can use the energy and heat emitted by radioactive decay deep underground. Indeed, these are all true.

We are thus expanding our understanding of the extremes under which life can survive. We are getting past our myopic view that life must be very much like us, in order to exist. Microbes have been proven to be incredibly robust. Some have even been attached to the exterior of the International Space Station, where they have been exposed to high radiation, extreme temperature changes, and a total lack of atmosphere for over a year... and they survived!

What fascinates me is the implications that these discoveries have had on our guesses about the existence of extraterrestrial life. Earth offers very cordial conditions for life, compared to the harsh environments found elsewhere. Life thrives on our planet, in countless forms and in many pleasant ecosystems. Until these recent discoveries of life existing in harsh locations, scientists were inclined to discount the possibility of life other than on Earth. Many people thought that our little planet could be the only place in the universe where life arose. This is turning out to be a narrow-minded viewpoint.

Now we are thinking differently. In fact, right here in our solar system life may have gained a toehold in places other than Earth. Mars is looking more and more likely that it may have had life, a few billion years ago. Europa—an ice-covered moon of Jupiter—is thought to harbor an internal ocean of water; in conditions not that much different from Antarctica. Researchers are making plans to visit Europa and run experiments to see if life may be found there. Other moons in our solar system may have conditions where life may be able to survive. Farther out in space, thousands of planets have been discovered orbiting their stars. Preliminary findings suggest that some of them may be conducive to life. Life almost seems simply to be waiting for us to find it.

The existence of extraterrestrial life has, until the last couple of decades, either seemed doubtful or was confined to the realm of science fiction. Humanity is beginning to realize that life just may be abundant in our universe. Stay tuned... the answer may come in another decade or two.

Defining Life

A question that continues to pester science is: What is life? One of my dictionaries offers this definition: “the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.” That seems to cover the topic quite well, but it has a problem: it may work well for distinguishing life on this planet, but how about other worlds in space? It also assumes that we know what an animal and a plant is—as well as being able to tell what “functional activity” means; and finally, death. These definitions depend on what we know about life on Earth; leading us to think that we will recognize life elsewhere when we see it, wherever it is.

But as we look out toward other bodies in the universe and wonder if we're alone or not—if life may have emerged elsewhere—could we even recognize it on alien worlds? In recent decades scientists have discovered here on Earth several species of what are now called “extremophiles”: microbes that live in habitats that we once thought were impossible for life; such as next to hot and toxic undersea volcanic vents; highly acidic pools of water; and deep underground locations, far from the sun and any source of plant nutrients. So our definition of life—and the conditions under which it can survive—has had to be widened.

Now we are on the verge of exploring other worlds in our solar system, upon which we know some of these extreme conditions exist: Mars, Jupiter's moon Europa, Saturn's moon Enceladus, and others. Scientists are eager to check them out, and we may well be able to do so, in another decade or so. An even greater stretch of our ability to detect life may come when we develop better instruments to evaluate the properties of planets orbiting nearby stars.

Our ability to tell whether life exists “out there” hinges on the adequacy (or breadth) of our definition of it. Researchers keep offering updated definitions, but for every one put forth, other scientists quickly come up with a counter example even here on Earth that nullifies it. Take the reproduction part of the definition of life given above: What if we found some entity on the moon Europa that seemed to be alive, but showed no evidence of reproducing? Maybe it just has a very long reproductive cycle. How long do we wait, in order to say yes or no? What might death mean on Enceladus? How do we judge whether something has “functional activity” on an alien world?

Our current understanding of biology is still a little too primitive to come up with a clean definition of life here on Earth, let alone on some outer-space planet. For example, in the late 1970s the two Viking spacecraft that landed on Mars had the explicit objective of determining if life could be found there. The limited design of the Viking experiments, however, did not allow a decisive answer. NASA may have even conducted the wrong kinds of tests.

We'd better keep our minds open and not try to nail down the definition of life, until we are able to get to an alien world and observe what conditions prevail there. It just might show us something beyond our wildest expectations, and even beyond our current ability to wrap our heads around.

Unlikely Alone—Part 2

If life is discovered on other worlds, it will have a profound impact on our psyches. Some of us will have the foundations of our beliefs dramatically shifted and will have to rethink our basic convictions. Earth and humans will no longer occupy the pinnacle; this precious little planet will no longer be the only vital place in the universe. Others will rejoice that the cosmos is as rich as we could ever have imagined. 

The discovery of extraterrestrial life—if it comes—will not come any time soon, however. Moreover, the forms of life we discover will quite probably be of a type that we as yet can't begin to guess. Our current expectations of what we might find are probably too restrictive. The various scenarios that TV and movies have portrayed (aliens who usually look and talk like us—especially using modern English) are far too limiting.

Scientists have frequently speculated on what kinds of life we might find out there—describing the conditions under which “life as we know it” may exist. We’re coming to see that that view is too narrow, as we've been taken aback by the new types of life we've found right here on Earth—the so-called “extremophiles” that I mentioned earlier. Clearly our understanding of types of beings that we can't currently conceive of will soon be expanded even more, as we continue to explore our planet. 

I also wonder if we could even recognize some other strange form of life elsewhere in the universe, were we to encounter it tomorrow. It took us a long time to “discover” some of those extremophiles right here on Earth. 

To date, we have only one example of life and only one vital planet that we know about. With just a single sample, there's no saying that life has evolved “out there” as it has here. Even if we could rewind history and replay evolution on Earth, there's no telling what creatures would roam our planet today—but it certainly would be dramatically different. So many random events occurred along the way that would never be repeated—events that changed the course of evolution and altered life. (Think of the improbable asteroid that blew away the dominant dinosaurs, 65 million years ago, removing them and opening up so many niches for mammals.)   

Furthermore, it's taken something on the order of 3-4 billion years for life on Earth to evolve from some unknown ancient seed to the complexity we see today—that’s several billion years for a technologically proficient form of life to evolve on our friendly little planet. The chances of our finding life on some distant planet that is anywhere near as advanced (or immature) as humans are has got to be incredibly remote—given that they may have begun billions of years before us or are just getting started. We might find ourselves unable to communicate with beings who are either primitive or much further advanced than we. 

And the distances involved! The universe may be teeming with life, but those beings could be so unimaginably far away that we may remain ignorant of them forever.

So, where are we, in being able to answer the question, Are we alone? We've no more a definitive answer than 100 years ago. It's still an unknown, even though the likelihood seems to be much greater than even a year ago. Expect to live with the mystery for a good while yet. Don't hold your breath—just open your mind a little more to the possibility.

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…

Extra Terrestrial Life

A question has hovered in the minds of people over the eons: Does life exist elsewhere in the universe? I have written before on this subject (“Life Out There,” 11/20/08). It’s an ongoing question that we’ve been unable to answer so far, but now seem to be closing in on. Several exciting initiatives recently have been launched—and some of them are providing tantalizing information.

There are fewer questions whose resolution would have a greater impact on us than: “Are we alone?” Many people have invested lots of energy into a belief system that the Earth is unique in the entire universe, and thus solitary in harboring life—especially intelligent life (whatever that is). Others are convinced that the conditions that fostered life here are common throughout the vast universe and thus life must be common. They argue that, even though Earth’s life-favoring conditions are incredibly rare, there is such an unimaginably large number of stars, that those conditions must have been duplicated many places.

This is similar to the ancient debate over whether the Earth sat at the center of the (then-known) universe. Arguments about our place in the cosmos raged on in those times, until science progressed to the point that the answer was found: we’re far from the center.

Similarly, our understanding is now growing about the possibilities of life elsewhere. In the last few decades we’ve discovered extremely tough species (dubbed “extremophiles”) in places here on Earth where we’d previously doubted any form of life could survive: scalding hot pools in Yellowstone, frigid locations in Antarctica, the sunless depths of the ocean. Simultaneously, NASA’s probes have discovered environmental conditions on other worlds in our solar system—a few moons of Jupiter and Saturn—that are quite similar to those tolerated by Earth’s extremophiles.

The December 2009 issue of National Geographic describes very recent results of astronomical studies that have identified nearly 400 planets orbiting stars other than the sun. Many people have long suspected that there must be planets circling other stars, but the proof has been lacking until now. Now we know: over 300 of the nearest stars have multiple planets! And those that we can detect thus far are just the bigger planets (far larger than Earth). Projects are underway that will soon be able to detect Earth-sized planets in the next few years—and even begin to analyze the contents of their atmospheres (if they have any).

Just as Johannes Kepler finally proved that the sun (not the Earth) is at the center of our local universe 400 years ago, we’re on the threshold of discovering if life on other earths exists—or not. Stay tuned.