ET Inspections—Part 1

There is much research and speculation currently going on, regarding the possibility of life elsewhere in the universe. The search is vigorously proceeding, on the part of several scientific disciplines: astronomy, physics, biology, chemistry, and evolution. Now that thousands of planets have been discovered around nearby stars, we know that worlds exist where life might possibly be present. The recent discovery of hardy life forms right here on Earth, thriving in extreme environments (high/low temperatures, dessicated locations, high-acid spots, sunless pockets, etc.), tells us that life can flourish in what are extraordinarily harsh situations; once thought impossible for life to even exist.

At some point in the future, humans will travel to other worlds where life could potentially exist, and we will be inspecting them for possible forms of life. A pertinent question that could be posed is: Would we recognize life of a very different kind, if we visited its world? Just a few years ago researchers would have doubted that life could exist in some of the extreme places found here on Earth. It has prompted scientists to open up to the possibilities of bizarre life forms elsewhere.

Maybe a way to put the search for extraterrestrial (ET) life in a different perspective is to conduct a fanciful thought experiment. Suppose we think about some intelligent outer-space species that might have visited planet Earth to inspect it for life, at different times over our planet's existence. Suppose we look at what these ET visitors would have observed, and what they might have concluded from their inspections.

Visit 1, four billion years ago. That would have been only a half-billion years after Earth had formed. It would be a molten, heaving surface of lava, with spewing volcanoes. No life possible then.

Visit 2, three billion years ago. While cruising our solar system, the visitors would also have checked into both nearby Venus and Mars. All three planets would have been water worlds with thick atmospheres, and were quite warm. Had they looked closely on Earth at that time, they'd have detected some single-cell, simple life forms. Nothing intelligent. Not much going on here, but some possibilities for the far distant future. Would the outer-space visitors have found similar kinds of primitive life on Venus or Mars? It's certainly plausible. We humans may someday find out, when we have conducted our own inspections of our partner planets.

Visit 3, two billion years ago. For millions of years around that epoch, Earth's temperature had dropped far below the freezing temperature of water. Our visitors would have encountered what scientists call “Snowball Earth.” The planet would have been essentially encased in ice. At first glance, it would be doubtful that life could have existed under such conditions, but had the space voyagers probed a little deeper, they'd have found that single-cell critters did live beneath the ice, deep in the oceans. Astronomers today think that similar kinds of life may be found by humans one day in ice-entrapped oceans on Saturn's moon Europa. Still, our ET visitors would just find primitive life here on Earth—no intelligence yet.

More visits next time...

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.

Prodigal Planets

Astronomers have made many exciting discoveries in recent years. For example, we now know—thanks to NASA's Kepler space telescope—that our Milky Way galaxy hosts hundreds of billions of planets; a fact that was mere speculation just a couple of decades ago. We also know that far beyond Pluto, our own little solar system contains hundreds of thousands of proto-planets that orbit the sun. (In fact, Pluto itself was recently downgraded to a “dwarf planet,” losing its role in our solar system's eight-member planetary family.)

Many other recent discoveries are being added to the list. For example, the Juno spacecraft now orbiting Jupiter is giving us a far greater understanding of that giant planet. The Cassini mission, now in its 12^th year flying around Saturn, is revealing many discoveries that are changing our understanding of how planetary systems form and what conditions might lead to life in the universe. Black holes have been discovered in far-off galaxies. Gravity waves have been measured. The list goes on. It's an exciting time in the cosmological world.

A new discovery that I will focus on here is the recent finding of free planets that wander alone in our galaxy—unattached to any star; not a part of any solar system. Until recently, the reality of these prodigal planets was, like planets around other stars, mere speculation. But now a few have been observed. It's very difficult to spot these dark wanderers through interstellar space. They cruise through a black void, nearly invisible. Recent advances in telescope technology are allowing us to locate them.

So now we've spotted several of these solitary worlds—enough to give astronomers the confidence that these free-floating planets are quite common. In fact, there are probably hundreds of billions of them wandering alone through the Milky Way.

The mystery: how did they get out there? Aren't planets formed only around stars? In fact, these lonely planets were created in a similar manner to the planets in our own solar system: through a gradual accumulation of bits of rock and dust and gas surrounding a newly-formed star. But then something like a gigantic slingshot action occurred, as one of them gravitationally encountered a huge planet in its solar system, flinging the smaller planet out into space—destined to become a lonely body free of its originating solar system; forlornly meandering through the ages.

Are these prodigal planets destined to be forever lonely and relegated to being just a cold pile of rocks? Could they ever possibly host life? As improbable as it seems, they theoretically could harbor life. Some scientists speculate that, despite having no star to provide warmth, conditions just may be that warm-seeking life could have come into existence in such a forbidden environment. The scenario is completely conjectural, but radioactive decay deep within such a planet could provide the required warmth. Or a thick covering of ice could hold in the necessary heat.

It's all guesswork, but the point is that, before the discovery of these prodigal planets, we had no idea that they even existed. Now we now they do. The fascinating thing is that they conceivably could harbor life. What's more, they are far more accessible to spacecraft from Earth than planets around distant stars, since they float alone, and some of them might be closer than planets still accompanying their star. We would just need to locate a couple of them and send spacecraft out there to investigate.

Who knows what we might find next in outer space? Just a few years ago we had no confirmation that billions of planets are out there in our galaxy. We had no idea that moons of Saturn or Jupiter just might offer conditions conducive to life. Cosmology is advancing at a breathtaking pace. Stay tuned.

Anybody Out There?—Part 1

One of the most intriguing questions that has increasingly become the subject of scientific investigations, as well as popular media speculation, is the possibility of extraterrestrial life. Are we alone in the universe? I have played with this question in several past postings of this blog. I recently read an article on the subject that raised another fascinating aspect to the question. Here's the essence of it.

Science has edged relentlessly closer to the hypothesis that, indeed, there may well be life out there, for several reasons. (1) We now know that there are billions of planets just in our galaxy alone—something for which we had no evidence just a few years ago. (2) Researchers are getting better at understanding the conditions under which life may have spontaneously originated; if so, it could have done so in many locations throughout the universe. (3) Our space probes have discovered complex organic molecules on other bodies in space, such as comets; which were present at the beginning of our solar system, 4.5 billion years ago. There is a strong possibility that these molecules may be able to initiate life, when conditions allow. (4) Science has widened the conditions under which life can survive, if not thrive—conditions we only recently thought would be too hostile, until we discovered life thriving there, right here on Earth. (5) We also now know that some forms of life can survive the incredibly harsh environment of space, which potentially makes it possible for life to travel (as hardy microorganisms) from one planet to another.

Clearly extraterrestrial life has not yet been found, but we seem to be much closer to discovering it, if it's out there. Recent findings by the Mars rovers have directed our attention to that planet—giving us greater expectation that life may be found there. Scientists are excited by the prospect of this age-old question soon being answered. Thus many of them are turning their attention to what we may discover, if we do find life out there. We'd best prepare so that we are not taken by unpleasant surprises.

Suppose we do come across life elsewhere. It may come in a form that is utterly different from what we expect. Will we even recognize it as life? And the big question: Will it be intelligent—whatever that means? If so, will its intelligence resemble our own? We tend to regard our high-tech smart phones as evidence of our acumen. The guy who invented velcro was very smart; so was the team that discovered the Higgs boson last year. Ants are dumb, by human standards, but they've been around for over 100 million years. Is that not an example of a kind of intelligence? So if there is intelligent life elsewhere, its type of intelligence may be completely unexpected by us. We'd best keep our minds open.

There's another fascinating aspect about discovering intelligent life out there: technologically speaking it may be millions (or even billions) of years ahead of us, or just getting started. Earth is some 4.5 billion years old and life appears to have begun on our planet less than a billion years after it formed. So life has been here for maybe as long as four billion years. Think about that: it took some four billion years for humans to attain the advanced technological state we now find ourselves in. And our highly developed civilization is only a few hundred years old. Where might we be in another 100 years? Or 1,000 years? We can't begin to guess. Any of our predictions in the past have been far wide of the mark. And science fiction is of little help; their scenarios are usually quite naive.

More on life out there, next time...

Origin of Life

I have recently read the book Seven Clues to the Origin of Life by the British author A.G. Cairns-Smith. It is written in the manner of a forensic analysis, as is classically described by Arthur Conan Doyle’s novels of Sherlock Holmes, as Holmes delves into the evidence in the wake of a crime. The book takes this “Holmesian” approach in considering how life might have arisen on Earth. That is, rather than suggest a hypothesis and then explore it to see if it makes sense, Cairns-Smith ponders all the clues and arrives at a conclusion, after ruling out the competing possibilities.

I have read several other books by scientific authors on the origin of life on Earth, and find there is a wide variety of opinions on the subject. There remains considerable disagreement among scholars, since the cause of the origin of life on this planet as yet remains beyond science. Research is closing in on an answer very slowly, and may soon have an answer, but it’s presently an unknown. For now, we are left with guesses.

Western culture is very influenced by the version of life’s beginning that is presented by the Bible—a version that is, of course, mythical and therefore literally incorrect. The book of Genesis’ story is a metaphor, presented in poetry. It’s not science; it’s not intended to be science—it’s a folktale. The real beginning of life was quite beyond the ken of the ancient biblical writers; as is true for other ancient cultures, which also had their own genesis myths.

Life’s origins on Earth could have come about in two significantly different ways: (1) it somehow originated right here on this planet or (2) it originated elsewhere in the universe and then arrived here—both possibilities having occurred about 3 ½ billion years ago. These are two strikingly different scenarios. They offer a very contrasting view of the universe. Is life extraterrestrial or not? In case #2 it obviously is. In case #1 we may be alone in the universe. Again, the answer eludes us as yet.

Human religions are by definition people-centered; they cannot consider extraterrestrial conditions, such as in case #2. Cairns-Smith’s sorting through the clues can fit either case above. In the end, he offers the possibility that whether life began on Earth or elsewhere, it could have started with a seed that would not have been life as we know it, but some sort of nascent, self-organizing precursor. It then required just the right conditions to transform itself into life. In other words, life did not spring suddenly into existence, essentially from out of nowhere, but had a nonorganic beginning, which very gradually evolved into life as we know it today. It’s a neat kind of Holmesian mystery, solved in a unique way! Is it true? Maybe we'll know before long.

Odd Life

I have written a few times in this blog about the origins of life on Earth, as well as the search for life elsewhere in the universe. (“Unlikely Alone,” 2/28/13, “Goldilocks Globe,”1/30/11, “Extra Terrestrial Life,” 1/22/10, and “Life Out There,” 11/20/08.) When scientists talk about looking for extraterrestrial life, they often qualify their efforts as seeking for “life as we know it.” They are cautious enough to recognize that alien life-forms may not resemble ours—especially since more and more examples of extreme forms of life have been discovered right here on our little planet. Just a few decades ago science did not expect to find examples of the so-called extremophiles that we now know flourish in hot, acidic, deep oceanic, and underground locations.

A new arm of research is currently examining the possibility of life-forms here on Earth that even further stretch our current concepts of what life is. Life, “as we know it,” (so far) is carbon based, water immersed, and uses proteins made up of 20 kinds of amino acids and DNA that uses four kinds of chemical bases. We know, however, that nature contains about 100 types of amino acids and a dozen or more kinds of bases. Why does our type of life employ only a small fraction of the available chemical compounds? Could it use more? Could other forms of life use other compounds? And is carbon the only basis of life—why not silicon? Could liquids other than water be the basis of life?

These questions are increasingly being asked and explored by some scientists. They feel that it is possible that there may be other types of life living right alongside us, but we have heretofore ignored them, because our expectations of what life is have been too narrow. These scientists' explorations are being broadened to seek life forms that may be odd (to us).

This issue of alternative kinds of life is even more relevant, as we go looking for life elsewhere in the universe. In the 1970s, two NASA Viking missions to Mars were explicitly designed to test for Martian life—past or present. The Viking landers took samples, ran tests, and at first seemed to indicate they'd found life. A closer look forced NASA to declare the tests negative, however. No Mars life in those samples...or so they thought.

At the present moment the rover Curiosity is rummaging around in Mars's Gale Crater, checking to see if conditions there could once have supported life. NASA is careful to caution that this time they are not looking for life, just signs that conditions could once have been amenable for it. They've learned the lesson of getting too specific in the hunt for life.

But the newest scientific studies suggest that we may still have biochemical blinders on, when it comes to looking for life elsewhere. If there are unrecognized life forms sharing Earth with us, what even more odd forms might exist somewhere “out there?” Perhaps we should open up our minds even more.

When life first emerged on Earth—some 3.5 billion years ago—it may well have consisted of more than one chemical basis. As time passed, our type—carbon and water based—may have come to dominate. Evolution may have favored our kind of life and either eliminated the others as unfit, or relegated them to the margins, where we simply haven't noticed them. During the 150-million-year reign of the dinosaurs, mammals existed only as small critters who kept under cover and avoided the big reptiles. If you were to ask a dinosaur about mammals, he'd probably have shrugged (I believe they did have shoulders), having no clue that mammals even existed.

It's amazing what we open ourselves to when we let go of our selfish, narrow-minded viewpoints—whether the object of our attention is life forms, religion, food, or musical tastes. We have so much to learn. One of the biggest barriers to wisdom is our inability to step outside ourselves.

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…

Blink of an Eye—Part 1

 The March 2012 issue of Scientific American magazine has a fascinating article by Donald Goldsmith, an astronomer who once served as consultant on Carl Sagan’s 1980s Cosmos television series on PBS. In his article titled “The Far, Far Future of Stars,” Goldsmith points out that, while the glorious period of star and galaxy formation in our universe is largely behind us, the universe has a very, very long time yet to go, before it becomes a doddering, failing entity. In fact, this grand cosmos we inhabit is just getting started. It is yet in its infancy, at 13.7 billion years of age, according to the latest scientific understanding. Many exciting events are yet to come, and one of those, Goldsmith says, is that the universe will become increasingly conducive to life, as it ages further.

That, to me, is a remarkable fact, given the rapidly changing understanding in the scientific community, that the presence of life in places other than Earth is far more likely than we previously thought. Humanity has historically tended to believe that, in this entire universe, the solitary location of life has been our tiny planet. We are most special, according to this line of thinking, and are divinely delegated to be the single island of life and consciousness in this immense cosmos.

That self-centered perception is wrong, I believe. We still have a very limited understanding of the universe, and we are finding new facts every day. The more humanity has opened up to another-centered perspective, the more we have come to comprehend the reality of this incredible cosmos. Forms of life recently discovered in unlikely places on our planet are indicating that life can thrive in far more inhospitable locations than we once believed. There is an increasing understanding that life may well exist “out there” somewhere and we will soon prove it to be true.

Returning to Goldsmith’s message: There is a lot more history to come, in our fantastic universe. It is now a little shy of 14 billion years of age. In its very beginning, hydrogen and helium were the only elements existing in the nascent cosmos. The first stars were formed from these gaseous elements (99% hydrogen and 1% helium). When they quickly burned out (over just a few million years), they collapsed and the high internal pressures formed a few heavier elements—such as carbon, nitrogen, and oxygen. As subsequent stars formed over the next few billion years, more and more heavier elements were forged.

Eventually, there were enough heavy elements (maybe then 1% of the total  matter in the universe) that when a star formed, there was enough solid material present to form planets. When our cosmos was about eight billion years old, our sun materialized out of the existing local stardust, with enough solid material left over to form eight planets (nine, if you are old fashioned and wish to include Pluto). It required another five or so billion years to bring about complex life on this planet.

So what is the prognosis for our five billion year-old solar system? In another five billion years our sun will use up most of its nuclear fuel and will swell up to a red giant star. That process will toast the inner four planets, after which the sun will collapse into a white dwarf and slowly recede into oblivion. Any life aboard planet Earth will have long before been incinerated.

Meanwhile, in the rest of the universe, events will slowly, slowly wind down. The emphasis here is slowly… really slowly. After the Earth will be long gone, the universe will be just coming into its stride. The stars that form after our sun dies will have even more heavy elements and will last much longer than our sun. These cooler stars will harbor many more planets than our current cosmos holds and they will live for far longer—trillions of years, rather than billions. Life will have many more opportunities to arise and flower, in this far distant future. That forthcoming cosmos may be teeming with life.

More on the aging universe next time…