WHERE HAVE ALL THE E.T.'S GONE?

It’s strange that, living on a planet that teems with millions of different species, humans wonder if we’re “alone in the universe”.

The question usually refers to conscious, thinking beings like ourselves, not just any form of life. But the first step to knowing if there are other sentient beings in the cosmos is to find out if there is any kind of life beyond Earth at all. That’s not an easy search.

For one thing, it’s only in the past few decades that we could say for certain there are planets orbiting stars other than our own sun. It didn’t make sense that our sun would be one-of-a-kind, but it took modern astronomical equipment and detection methods to confirm the existence of extrasolar planets. Now astronomers speculate that most stars probably have planets, and most likely have one or two planets in the so-called habitable zone, which we define as habitable because their orbits should provide surface temperatures that allow for liquid water. It bears saying that the liquid water temperature range is what we humans and similar life forms require for survival, but even here on Earth we’ve discovered life forms that exist in hellishly extreme conditions, like deep-sea volcanic vents and under Antarctic ice. Plus we can imagine life based on elements like silicon instead of the carbon molecules that construct Earth organisms, increasing the number of planets that might be inhabitable by some kind of life. Given that there are hundreds of billions of stars in a galaxy and hundreds of billions of galaxies in the universe, the number of possibly-habitable planets is… really, really high! And let’s not forget that uninhabitable planets, like gas giants, might have habitable moons. (Jupiter’s moon Europa is a strong possibility for hosting life.) That multiplies the numbers yet again.

All of this should give a boost to science fiction writers because, in all the vastness of the universe, every one of our stories about strange alien species and civilizations could be reasonably plausible.

The skeptic will ask, “So where is everybody?” (known as Fermi’s Paradox.)

Which brings me to my second point, that signs of life are really hard to identify as such because they could have other causes. For example, living species are known to have provided Earth’s atmosphere with oxygen, but it can be produced by other chemical processes, too—oxygen markers in the spectral analysis of a planet’s atmosphere are no guarantee of life. So when it comes to basic life in general, we can identify places that have conditions we believe would support life, but we can’t know it’s actually there until we go and take samples. Look how challenging that’s been on Mars, and it’s the planet next door!

It should be easier to find signs of advanced alien life-forms because we expect civilizations to give off indications of high energy use, or even radiate electromagnetic transmissions like the TV and radio signals we’ve been shooting off into the void for decades. Except we have no reason to expect that an alien species would have senses comparable to our vision and hearing—they might not even be able to detect our TV and radio signals, much less interpret them, and we might not be able to detect their forms of communication. There could be lots of civilizations relatively near to us, yet communicating and using energy in ways so different from our own that we don’t recognize what we’re looking at. Or we’re not using the right instruments to distinguish them at all.

The difficulty is made many times worse by the vastness of the universe. In a recent study published in The Astronomical Review, the researchers wondered how much of the local galactic neighbourhood had actually been searched by SETI efforts (Search for Extraterrestrial Intelligence), listening for potentially alien radio signatures. They picked a zone of space roughly 33,000 light years across, comprising a good portion of our galaxy’s densest part plus nearby globular clusters, and they determined that, proportionally, the area that had been effectively searched was the equivalent of a bathtub of water compared to all of Earth’s oceans. I guess there’s a chance we could have missed something!

SETI was relegated to a back burner for a few years, but has now been welcomed back into the astrobiology fold, and there’s no doubt we will continue to expand the areas of space that we’re searching and improve our search methods.

Technology can be great. But will we put as much effort into the implications of all this? There are lots of big questions to be answered. How will our society cope with the knowledge that life exists elsewhere, especially if it’s an advanced species? How will we, as a race, behave when we encounter such life?

I’ll get into those things a little more in my next post. So keep your fingers crossed that ET doesn’t show up before then!

LIFE IS A TREASURE WORTH FINDING

I’ve posted recently about the search for extraterrestrial intelligence and the (so far) lack of success. But why are we so focused on intelligence? Wouldn’t it be awesome enough just to discover life elsewhere in this vast universe? Jumping high-five awesome? For some reason most of the attention and all of the angst has been centered on the idea that there might be other species of beings out there that might be interested in us for the purposes of a) contacting, or b) conquering. Yet the search has come up empty. Well, maybe intelligent life is as rare as a politician with his hands in his own pockets, and there are lots of reasons it could remain hidden from us, but the discovery of any kind of life inhabiting other solar systems would be cause for celebration.

This week NASA announced a brand new coalition of scientific endeavours to be known as NExSS (Nexus for Exoplanet System Science). Each of the partner projects will focus on different aspects of the search for extraterrestrial life including refined spectrometers better able to detect Earth-like planets, how planets form and where, the potential habitability of exoplanets (from a human perspective), tidal dynamics, how organic elements reach planet surfaces, and a lot of other topics.

I love this idea, and not just because of its geek-cool acronym. The practical side is that the more we know about how habitable planets get that way and how life arises and survives elsewhere, the better we can understand the challenges of our own planet and maybe even find solutions to the damage we’ve done to its ecosphere. God knows, we need all the help we can get in that department. But beyond the practical is the pure stomach-tingling thrill of a treasure hunt. Finding carbon-based life on an exoplanet would be like finding a long-lost cousin you never knew you had (who doesn’t know about all the skeletons in family closets). No, bigger than that—it would be like living all your life in a sheltered village and suddenly finding out that there’s a whole world just beyond the trees. There was a hint of that when the first exoplanets were discovered in the mid 1990’s, but the confirmation of extraterrestrial life would ramp that excitement up to a whole new level. Think of all of the new questions, and the answers, and…more questions.

Does carbon-based life require DNA? A cellular structure? Does it always follow a birth-to-death life cycle, or could there be forms of life that are effectively immortal? What about sex—we’re always fascinated by sex.

What if we find life forms that aren’t based on carbon? There’s been speculation, but proof would really upset the bioscience applecart. And that could be a good thing. Sometimes the best way to advance is to throw everything you’ve known up in the air and see what new patterns form when it lands.

Whatever we learn about life elsewhere is bound to open our eyes to secrets our own planet has yet to offer up, because I’m certain we haven’t yet found every type of life the Earth has produced, hidden in the depths of the ocean or the planetary crust. Not to mention other bioscience implications like the discoveries of new potential medicines. Learning how extraterrestrial life copes with unique or harsh conditions might teach us how to protect ourselves from nasty surprises like cosmic ray bursts or asteroid strikes, too.

Most of all, I love this plan because the discovery of life elsewhere would give us somewhere to go and a reason to get there. The human race is at its best when we have goals that inspire us, nearly unattainable heights to climb. A treasure just beyond our reach that requires us to dig deep within ourselves and strive together in community.

We could really use something like that right now, and NExSS just might point the way.

CLOSE ENCOUNTERS OF THE INVITED KIND

I’m a supporter of SETI—the Search for Extraterrestrial Intelligence. It’s worth devoting resources to find out if we humans have company in this universe in the form of other intelligent life forms. There are lots of good reasons to want to know, especially if it doesn’t require us to do more than look and listen for signs of other civilizations. But recently some scientists have become impatient that SETI hasn’t detected anything in the past thirty years, and feel that we should be more proactive about the search. That impatience is understandable. SETI methods are painstaking. Space is vast. Even though our ability to search the skies has increased enormously over the decades, SETI astronomer Jill Tarter is quoted in an excellent Washington Post article about the subject, saying, “We’ve explored one eight-ounce glass of water out of the ocean”.

So the impatient scientists believe we’ve been going about things the wrong way. Since the Kepler Space Telescope and other projects have now identified more than a thousand likely planets circling other stars, and a fair number might be the right distance from their star to provide conditions that support life, these folks think we should start beaming strong radio signals toward those star systems, inviting any alien civilizations there to become “part of a conversation”.

Now hang on just a minute. Imagine yourself taking a walk in a strange neighbourhood at night. Would you keep your ears tuned to hear if anyone was around? Sure. Would you jump up and down and yell, “Helloooo! Anybody out there? Anybody feel like getting together for a coffee?”

I don’t think so.

For one thing, who do you figure is most likely to respond to your invitation: Mr. and Mrs. Nice-to-know-you, or the neighbourhood muggers?

I’ve always wanted to believe that a species advanced enough to travel between the stars would be peaceful. But there’s no evidence to support that, and plenty of evidence from human history to suggest that I’d do as well to believe in unicorns and leprechauns. Humans advanced enough to travel between continents certainly weren’t peaceful. Ask native North Americans or the Aztecs. In fact, experience on this planet has shown that technological progress is most often for reasons of aggression. Should we compare the research and development budgets of the military around the world to private R & D spending? And of all the reasons for expending resources to get into outer space, population pressures and a desire to exploit what we find rank high. Making new friends probably isn’t even on the list.

Even if extraterrestrial travellers weren’t malevolent, they would surely be so far ahead of us that we’d be curiosities by comparison, or even lab rats worthy of further study but certainly no treatment as equals. The knowledge of their existence alone could destroy all motivation for the human race to make progress of our own.

The point is that we have absolutely no way to know if intelligent aliens would be nice, or very, very bad. But once we let them know we’re here, there’s no putting the cat back in the bag.

Some 28 (so far) notables in the scientific community, including Elon Musk and David Brin, have signed a petition condemning so-called active-SETI. Stephen Hawking thinks it’s a crazy idea. Even the originator of the SETI movement, Frank Drake, believes it’s too soon and a waste of time.

As we venture out into interstellar space on our own we may discover we’re not alone, but by then we’ll be much better equipped to deal with whatever—and whomever—we find. For now, let’s be content with paying attention and not calling for attention.

WHERE IS EVERYBODY?

It’s called the Fermi Paradox: if the universe is so big that intelligent life must have evolved somewhere other than Earth, where is everybody? Why haven’t we seen any signs of them, or at least their TV commercials—those are unavoidable, no matter who you are, right?

Well, first of all, why are we so confident that there must be intelligent life elsewhere? Mainly because the universe is so big: our own galaxy is thought to contain 300 billion stars, and the universe we can see appears to have more than a hundred billion galaxies, so what are the odds this is the one and only planet that produced intelligent life? And that argument was made long before we actually knew that other stars had planets. Scientists working with the Kepler Space Telescope have now found thousands of possible planets orbiting other stars, and feel confident enough to consider more than one thousand of them “confirmed planets” (as of this month). A star system designated Kepler-444 has five rocky-type planets (like Earth) and was formed over eleven billion years ago. By comparison, our own solar system is only five billion years old. So if planets have been around at least that long, mustn’t some have produced life, and probably intelligent life, long before now? After all, here on Earth we’ve found that life can arise under even the most extreme conditions.

But The Great Silence is a fact. The Search for Extraterrestrial Intelligence (SETI) has been going on since the 1960’s, first searching for radio signals, and then many other signs of the by-products or artefacts of civilization. At one point SETI was scanning a billion frequencies of electromagnetic radiation, looking for some kind of signals. Granted, our own planet’s electromagnetic noise has only been spreading outward through space like an expanding bubble since the dawn of radio a hundred years ago, and signals from other galaxies would take millions of years to get here. But why is there such deafening silence within our own galaxy?

Here are some speculations (of my own and others):

- God took one shot at it and was satisfied with the result. (Yes, I’m being facetious, but somebody would’ve said it.)

- Truly intelligent beings recognized television for what it is and banned it forever.

- A lot of species stuck with the landline telephone rather than let cell phone companies gouge them. Or (more seriously) they went straight to line-of-sight communication using light, rather than spraying EM radiation in every direction.

- There are lots of hyper-intelligent races but they recognize that exposure to superior technologies kills a species’ initiative, so they’ve agreed to leave us alone (except for a few slip-ups, but then look how many times Star Trek captains blew the Prime Directive).

- There were lots of intelligent species, but they couldn’t get along and killed each other off.

- Other life forms are so completely different from the kind we know that they also communicate in ways we can’t recognize.

- Maybe the odds of life springing from a soup of organic chemicals and then evolving into a self-aware intelligence really are so low that, out of our whole galaxy we’re the only lottery winners.

There are many, many more serious explanations for The Great Silence. Maybe advanced species build Dyson spheres around their whole suns and have plenty to keep them busy without going anywhere else. Or maybe cosmic ray bursts sterilize huge chunks of galactic real estate on a regular basis. You can read a couple of great articles on the subject by George Dvosrky at io9 here and here.

But we can’t ignore the possibility that aliens have seen our TV shows and decided we’re just not worth talking to. The Kardashians and the House of Commons channel could keep us isolated for years to come.