Is Anybody Out There? On Finding E.T., Remembering Ray Bradbury [VIDEO]

I was 12 years old when I read The Martian Chronicles by Ray Bradbury. Don’t let that age fool you — I considered myself to be a very sophisticated reader at that age, having already read In Cold Blood, Helter Skelter, The Exorcist and other culturally impacting literary works.

But I was not prepared for The Martian Chronicles…the way it eerily pulled me in to its imagined, alien world not-so-distant, or different, from ours. What kid at that age and time had not already contemplated life on Mars, or on some other orbiting planets around distant stars?

I was still, overall,  a wide-eyed child of the Space Age — having stayed up late at the age of seven to watch the Apollo 11 Moon landing, having memorized (and drawn) every nook and cranny of the Lunar Module — I was ready for some science fiction that might not be fiction some day. With its sublime, almost poetic narrative, TMC opened up a whole new mental landscape : the possibilities of long-term habitation on an alien planet. How courageous a mission, how wondrous…

But there was one horrific scene in the book that stands alone in my memory:  A ‘Martian’ — one of the last remaining — disguised as a human, turns on his horrified human colonist-companion, killing him, silencing his bone-chilling screams.

I was not prepared for that. I recall having at least one night of terrifying mares and sweaty, heart-pounding awakenings, thanks to Bradbury’s other-worldly tale (that was, in retrospect, a re-telling of the European invasion of the New World). And all I remember thinking was: The Aliens will hate us, turn against us, just like the Indians did in the Old West.

It was the first time  I had contemplated the possibility that alien life (of an order well-evolved beyond microbes and marine crustaceans) might not be so receptive to human contact; that they might see us as invaders, as the dieing Martian race had viewed us in Bradbury’s chronicles.

Published in 1950, TMC was perhaps the modern, literary  impetus for the cinematic trend of  “space horror” films that was to come. Although certainly, other visions of alien horror were already  in the collective consciousness (H.G. Wells’  War of the Worlds), but these were usually aliens invading us — a far more expected source of horror and fear. Bradbury’s haunting ‘sci-fi fantasy’ novel seemed definitive and seminal. And not to forget the late-sixties TV series Star Trek — a series inspired by Ray Bradbury — that boldly took us to the ends of the galaxy and beyond — where aliens were not always receptive, and sometimes even down-right hostile.

My youth was saturated in dreams of space exploration. But I began wondering, in the back of my mind, how we would be received if ever first contact were made in the course of our explorations, or future colonizations.

As an adult — having long since given up my UFO enthusiasm to more skeptical, scientific possibilities — I became, like many, an eager reader and follower of our early steps towards exploring space, whether within our solar system or far beyond it.

Later on, Carl Sagan would become my scientific hero and cosmic chaperon. Through watching his PBS series Cosmos (based on the book of the same title) I learned about SETI (Search for Extra-Terrestrial Intelligence) and the Drake equation (formulated in 1960 by astronomer Frank Drake), which, after all variables were calculated, indicated that life-supporting planets should be plentiful in the universe, even within our own galaxy. It seemed only a matter of time before we found “them”, or signs of them, via radio telescopes most likely.

As the 1990’s transpired with a few astronomical glimmers of the first extrasolar planets, or ‘exoplanets’, I was confident that soon, we would detect signs of alien life (which at that time, I thought, would be no more than sufficiently strong radio waves similar to what we humans were emitting). There were perhaps a half dozen known planets outside our solar system back then. Then came the new wave of space-based telescopes lead by the Hubble Space Telescope. Together with the expansion and improvement of ground-based telescopes (such as those at the European Southern Obseratory, ESO), the stage was set for Golden Age of exoplanetary discovery. Now, nearly 12 years into the 21st Century, the catalog of confirmed exoplanets has grown more than a hundredfold.

Most of these are ‘Hot Jupiters’ and ‘Hot Neptunes’ (comparing such finds to analogs in our system) with a smaller percentage being ‘super Earths’. A few of these latter types are just a few times larger or more massive than ours, and are orbiting within the habitable zone of their parent star — a circumstellar ‘Goldilocks’ zone not too far, or too close, to its sun, where water might exist in liquid form. And, though relatively few in number now (just over 200), the number of these candidate super Earths is sure to increase in the coming years.

Surely, it seems, we are homing in on on E.T. But finding E.T.  — or even some simpler variety of life — is not so easy; the search area is unimaginably vast, and the possibilities for missing subtle clues or signs are enormous. And yet, given the calculated likelihood of advanced alien civilizations (that Drake equation again) scattered throughout the galaxy, one might expect some sign to be detected by now.

Examining Gliese 581 – So Far, No Sign of ET

Consider then, Gliese 581, a red dwarf star only 20 light years distant with its own unique solar system. Since the 2007 discovery of a ‘Super-Earth’ (over 5 times the mass of the our Earth), Gliese 581c, orbiting right at the outer-most edge of its calculated habitable zone, the star has been the focus of renewed exoplanetary hunting, with up to three more planets having been found in this system in the past two years or so  (apart from its two, earlier-known planets, one of which is a ‘Hot Jupiter’).

One of these more recent discoveries — a rocky “Super Earth” planet named 581d –could be just inside, or just outside, the inner habitable zone depending upon the nature of its atmosphere. Recent follow up investigations and simulations of this rocky, candidate super Earth indicated that insufficient greenhouse gases exist on its surface, and that the planet has most likely suffered from “atmospheric collapse.”

As to 581c, based on comparison with Earth climate models, planet ‘c’ is now believed to be the victim of a ‘run-away greenhouse’ effect.

Also, there is some partial evidence of a suspected 6th planet, orbiting between ‘c‘ and ‘d‘, which would put it in the middle of the planet’s habitable zone. However, this ‘g‘ planet has not been verified and many astronomers dispute its existence

SETI Tunes In

Still, it was only natural for the ET hunters at SETI to turn to Gliese 581 and its solar system to search for signs of alien life. Indeed, SETI had already detected hundreds of curious signals coming from (it seemed) the vicinity of Gliese 581. Using new automated analysis technology known as Very Long Baseline Interferometry (VLBI), which allows for more precise and “targeted” searches, SETI astronomers looked at 222 candidate signals coming from this solar system.

The actual, long-baseline array that applied the VLBI technique is located ‘down under’ and is called the Australian Long Baseline Array. The array is a a triad of powerful radio telescopes, located a few hundred kilometers apart but which when combined, act as one huge radio telescope with an angular resolution capability as fine as one milli-arcsecond (the finest resolution in all of astronomy).

The ‘bad’ news? The new VLBI was able to reject all of these signals as artifacts caused by our own orbiting, artificial satellites. The ‘good’ news? SETI researchers now have a powerful and precise tool for tracking down true signs of alien life.

Red Dwarf Stars – Once Ignored, Now the Focus of Much Planet Hunting

Speaking of red dwarf stars…in the early days of exo-planetary investigation, these small, “cool” stars (M class) were considered poor candidates for generating planets and entire solar systems of them. It was believed by many that these weaker stars lacked sufficient metallicity — the ability to generate heavier metals such as carbon, silicon, and iron required for large planet-sized bodies.

But due largely to the exoplanet discoveries around Gliese 581, a few astronomers started defecting from this red dwarf prejudice, deciding instead to give them a second (or third) look-see.

Lo and behold, it turns out that red dwarfs stars are veritable treasure chests of Earth-like exoplanets. That’s according to the team working with the HARPS spectrograph at the ESO La Silla Observatory in Chile. Red dwarfs are relatively common in our small sector of the galaxy — numbering about one hundred — with some 160 billion total scattered throughout our Milky Way galaxy (note: red dwarfs comprise nearly 80% of the stars in our galaxy).

Based upon a sample survey of 102 nearby red dwarfs, the team found nine super Earths, with two of these in the habitable zones of their stars (Gliese 581 and GJ667 C — the ‘G’ stands for Gliese).  But the team’s calculations produced a much higher estimate of red dwarf stars with super Earth’s in their habitable zones.

Indeed, the previously noted ESO team’s estimate may be quite off the mark, according to UW astrobiologist Rory Barnes. That’s because that former estimate did not take into account a gravitational heating effect caused by immense tidal forces acting on planets orbiting close to their red dwarf parents. These planetary orbits are not perfectly circular (thus evenly spreading out such forces), but are quite varying in their distance from their star,  causing the planet’s tectonics to “flex” and contract repeatedly, and  making conditions too harsh for a liquid water surface (and the possibility of a stable biosphere). The effect would be similar to the regular vulcanism seen on Jupiter’s moon Io.

Taking this effect into account limits the size of habitable zones, and thus also it limits the number of planets within them — reducing the total number of habitable zone-dwelling super Earths by as much as half.

Ok, so that leaves us with a 20% chance of finding habitable zone super Earths orbiting red dwarfs.

Other Stars, Other Solar Systems

But if red dwarf-bound exoplanets continue to come up empty in terms of signs of life, not to worry, there are plenty of  other planet-forming stars in our neck of the galactic woods for SETI to investigate.

In fact, according to a recent exoplanet survey conducted by Lars A. Buchhave, an astrophysicist at the Centre for Star and Planet Formation at the University of Copenhagen, and colleagues, small planets (like our Earth) are probably more widespread in our galaxy than once thought.

Previously, it was thought that small planets only formed around stars with a higher metallicity — rich in certain heavier elements like carbon, magnesium and iron (note: high and low metallicity is gauged by comparison to our sun’s metallicity).

The team looked at the chemical compositions of over 150 stars that are home to 226  candidate planets, smaller than Neptune. They found that small planets were just as likely to be orbiting stars with less heavy element capacity (such as M-class stars).

Their work also lends more substance, so to speak, to the ‘core accretion’ model of planetary genesis in which vast discs of ancient dust accumulate into planetesimals which, in turn, coalesce into larger, harder, and heavier planets.

A Good Candidate (for a life-fostering exoplanet)

At just 600 light years away, The sun-like Kepler 22  recently had its exoplanetary ‘first’: Kepler 22 possesses a Super-Earth, 22b, which is situated in the middle of the star’s habitable zone — the fist Earth-like planet ever found in a ‘Goldilocks’ zone where liquid water might exist. And, spectral analysis determined that its surface temperature is about 21 °C. (72 °F).

The planet Kepler 22b is just 2.4 times the size of the Earth and was discovered by the Kepler Space Telescope in November, 2011,  shortly after it became operational. The Kepler mission is to scan some 150,000 stars  for signs of planets transiting across their sun’s disc, slightly dimming its light in the process. The Kepler telescope was designed specifically for this exoplanet hunting purpose and to date has detected nearly 1100 planetary candidates.

Stay tuned to the Kepler mission in the coming months and years, folks.

[Update – January, 2013: As predicted, yet another ‘Super Earth’ — KOI (Kepler Object of Interest) 172.02 — has been found, and this one is {so far} the most Earth-like exoplanet found in a sun-like star’s habitable zone, with a mass of just 1.5 Earth masses!]

Searching for Signs of Alien Life or Civilization

All well and good, but the reader may have been wondering jut exactly how one detects ‘signs of life’ on a planet that’s hundreds of light years distant…?

This is a good question and the and the answer has to do, generally, with light or the wavelengths of light both visible and invisible to the human eye.Viewed from space , the night side of the Earth appears peppered with clusters of lights — emitted largely by human, electric lighting and fire burning. Large patches of light (e.g., on the Eastern sea board of the U.S.) are large urban centers and clusters of centers where most of the human population of the country (and the planet) dwell.

Recently, an astrophysicists named Avi Loeb suggested that the best way to locate ‘E.T. civilization would be to look for similar nighttime lights on distant, rotating worlds. Here, astrobiologists would be attempting to measure the “total flux” (of light) from the target planet, as compared to another without such lights. The key here is that artificial light (an indicator of advanced intelligence) would emit a different signature flux (producing a ‘logarithmic slope’ in the instrumentation)…So, we look for this slope and badda bing, we’ve spotted E.T., right?

Well, not quite, not yet.

While being an excellent indicator of advanced technological intelligence, the problem here is that we do not have, as of yet, powerful enough telescope to detect this kind of light. Such lights from highly populated urban clusters quickly grow faint, then invisible, as one moves out into space past a few trillion miles. Our best telescopic technology allows us to see (potentially) a large urban city’s lights from a distance of about 100 trillion miles, which is pretty great, but not by galactic standards. We would need new telescopes that were many thousands if not millions of times more sensitive to see them.

On the other hand, some planetary features generate heat that propagates in the infra-red spectrum, and given enough heat output, this should be detectable via Infra Red (IR) spectrometry, even from a great distance.

That’s exactly what astronomers were able to achieve just recently using NASA’s Spitzer Space Telescope. The telescope was able to detect light from a super-Earth — called 55 Cancri e — for the first time. The “odd ball” planet is a G-class sun 41 light years from us and was actually discovered in 2004, but it was only during this second look and analysis that infra red light was detected

Unfortunately, again, 55 Cancri e orbits 28 times closer to its parent star than Mercury does to our sun,  giving it a surface temperature of over 3000 °F (over 1700 °C), resulting in a very thin atmosphere (it’s actually oozing into space!) and no possibility of liquid water.

Ah well, at least the analysis showed that we can detect such signs from so far away.

Verifying Life Out There by Verifying Life Down here

Speaking of infra red light and detecting signs of life on distant worlds, one important ‘proof of principle’ came in just recently — sounding at first like some astronomical joke — with astrophysicists proving, definitively, that there is life on planet Earth after all.

In the hunt for Earth like exoplanets, the problem has always been: how does one discern true indicators of a biosphere  on an alien world, orbiting a star, many light-years distant?

In theory, an ‘Earth-like’ planet possessing a biosphere comprised predominantly of vegetation (of some kind) should be detectable based upon the type of polarization of light reflected by it, or its moon, back into space. Reflected sunlight should polarize differently depending upon the surface (e.g., a lake surface or forest canopy) that is doing the reflecting. Mass amounts of plant life should polarize the reflected light in a particular, circular form. And yet, the theory had never before been test on a planet which is known to have such a biosphere: planet Earth.

And so, the planetary scientists used their radio telescopes to look at Earth-reflected light coming off the Moon’s surface (which reflects light from the Earth as well as the sun) to determine the forms of polarized light that our planet was reflecting. Sure enough, they were able to detect circular polarization in some of the reflected light — the “signature” of plentiful plant matter. They also observed a greater amount of this polarized light in the 700 – 750 nanometer wavelength range (i.e., in the infra-red range). This so-called ‘red edge’ maintains a cooler temperature which preserves plant chlorophyll necessary for photosynthesis and survival.

Thus, in detecting such a high incidence of circularly polarized light, the scientists were able to determine that the Earth must have a good amount of vegetation on its surface…proving the existence of Life on Earth…and a proof of principle for analyzing reflected light from distant exoplanets.

So far, though, the technique has not “born fruit” in terms of finding alien life. And this leads us to the main interrogative of this essay:

So, Where is Everybody? The Fermi Paradox, Alternative Explanations and the ‘Mass Effect’

The reader will recall my earlier mention of the Drake Equation which calculates that alien life, or E.T. civilizations, should be fairly common throughout the Universe.

Standing in a sort of ‘default’ opposition to this equation is the somewhat lesser known ‘Fermi paradox‘ which, as the name indicates, was originally put forth by famed nuclear physicist Enrico Fermi before his death. Acknowledging the Drake calculation, Fermi surmised that the complete lack of evidence for any such E.T. civilization must mean that such civilizations, despite their presumed advanced status, tend to disappear (perhaps collapse) fairly quickly, thus leaving few or no signs of their existence (note: presumably, this includes “old” electromagnetic waves carrying communication data).

To account for the Fermi paradox, a theory dubbed the Great Filter was postulated, essentially stating that some great filtering mechanism — or some part of the evolutionary process —  is/must be at work limiting (possibly eliminating) such advanced, alien civilizations, despite the calculated probability of plentiful intelligence ‘out there’.

According to this theory, the lifetimes of these civilizations must be relatively short. This view is congruent with Fermi’s conjecture and though it might seem counter-intuitive, may offer a cautionary tale for our own civilization. Alternatively, the Great Filter theory asserts that intelligent life is a very difficult achievement, in terms of natural evolution, and would severely limit the number of advanced alien races.

Given that it took several billions of years for our biosphere to evolve from single-cell organisms to tree-dwelling primates with opposable thumbs, the idea that an advanced intelligence — capable of traveling beyond its native biosphere into space — might be difficult to achieve seems entirely reasonable, if a bit disheartening; we may be more alone, more “rare”, than we wish to believe.

As an alternative to these theories, we have the Zoo hypothesis, according to which there are indeed plentiful, advanced (“super”) E.T. Intelligences out there, but through some reverse version of the “prime directive”, they leave us alone (and presumably erase all evidence of their existence) so that we can follow our own, natural evolutionary course in the Cosmos. This is a somewhat more reassuring hypothesis, if not a more frustrating one (“Hey E.T.’s: Are we there yet?”)

And, I have my own alternative theory to explain the lack of contact or evidence:

Advanced alien races may also have long-left their home planets — which may have been destroyed by meteor impact or experienced complete climate collapse — and whose surviving members may have ventured forth into the galactic ocean in one or many spacecraft. These ‘anchorless ‘ aliens would be extremely difficult to detect. They may have hitched a ride on one of the trillions of  ”rogue planets, or unbound free-floating planetary-mass bodies, that are coursing through our galactic space (and are also difficult to detect). Then again, one of those same trillions may have collided with the home planet — or even with the newly adopted, “unbound planetary-mass bodies” — utterly destroying it, and “them” (as in the recent Lars von Triers film Melancholia), or forcing them to “abandon planet” once more.

After all the foregoing, mostly scientific theorizing, there is a darker, more “sci-fi fantasy” type theory to explain the lack of evidence for, or contact with, advanced alien intelligence (Note: semi-spoiler alert coming).

In the popular, multi-level/multi-player video game Mass Effect we have a possible explanation for this lack of contact in the form of super-intelligent machines (an extreme example, perhaps, of the ‘run-away robot’ or Singularity scenario) that go about their programmed business of initially encouraging space exploration and then intercepting any such advanced civilization every 50,000 years before they venture too far afield from their galactic neighborhood, purloining them for their own, perhaps nefarious, cyborg-centric purposes.

It is a cosmically conspiratorial fantasy that is both an oddly possible but highly unprovable postulate (until one is intercepted, but by then, it won’t matter).

The Lessons of Ray Bradbury’s Chronicles and Some Ego-Deflating Last Words by Frank Zappa and George Carlin

Returning to Ray Bradbury and The Martian Chronicles…I recall having the thought that the story was meant as a prophetic, other-worldly allegory of what can happen, of what can go wrong, in seeking out other worlds — not just for signs of life, but for that future someday of permanent habitation on a truly new world (for us), when our own world experiences some mass cataclysm, or a biosphere collapse, perhaps.

Right now, climate scientists and biologists are seeing many species of animals moving northward and to higher elevations to escape warming conditions. In the process of this survival-based migration, these animals are pushing others up further, and in some cases, pushing them out…out of the adaptation game all together.

And we should always remember, it could just as likely happen to us here, first, before we cause it to happen elsewhere in the galaxy.

If anything, perhaps Bradbury’s tale will prompt us to clarify our motives and intentions, when we finally move out into space, not out of curiosity, but out of necessity…and to be more cautious and regarding of all life in our grand, space-faring dreams and colonizing schemes.

If all that isn’t a bit sobering for our (admittedly) grand and self-satisfying enterprise of searching out E.T. intelligence, I offer these humorous, hubris-annihilating (and not a little misanthropic) final thoughts from the minds and mouths of Frank Zappa and George Carlin in this cogent mashup video (note: the audio get very loud on the Carlin segment).

Frank Zappa and George Carlin on Space Colonization and Contacting E.T.

Thanks for reading. Keep looking up (but always look where you’re going).

Top Photo: The 64 meter radio telescope at Parkes Observatory (CSIRO)