Sunday, November 7, 2010

A hard blow for hope. Part I


These had been decades of prosperity. Some were starting to refer to them as "the golden age" of human progress in the entire recent history, going back several centuries into the past. And all of this thanks to a small star, not very different from our Sun, more than a hundred light years away. When one stopped to think about it, it seemed incredible how that little dot of light had exerted such a powerful influence in the course Humanity headed for. A dot among many, which a century earlier wouldn't have had even the slightest importance among the hundreds of thousands of its class in the whole of the night sky. But this dot, only this particular one, turned out to be special.

Everything started with an automated monitoring, one among several, of the brightness variations of a great number of stars in broad regions of the sky. Its aim, to detect the crossing of planets in front of them in case their orbits were aligned with our solar system. And this was one of the stars that fulfilled these conditions. It was among the ones that for a brief amount of time was partially covered by a gas giant in its orbit, and recorded as such. But unlike in others, this event would not repeat itself days or weeks later, not even in months. This planet had not migrated towards the inner regions of its system to remain exposed to temperatures able to melt metals because of the closeness to its star —it remained at a prudent distance since its formation. Almost fourteen terrestrial years were necessary for this distant sun to be eclipsed again by the giant, but by then the eyes of humanity were already completely turned towards this region of the sky.

While this colossus followed its path impassively, governed by the laws of celestial mechanics, changes in brightness and radial velocity of a much lower magnitude had started to attract attention. A few much smaller planets orbited the star in the inner regions of the system, with orbits between a few months and a couple of years long. Small rocky planets in the middle of what would be considered to be the habitable zone, exactly where you would hope to find a new Earth, and with masses that were not out of proportion. Bodies of this kind were starting to be found around other stars, becoming the first steps towards the answer of one of the great questions in history. When the sensitivity of spectrometers increased enough, the study of their atmospheres and composition came soon after, and it was then when the vision of the place of humanity's home world in the cosmos started to change forever. A decades-long search was being performed with the hope of knowing if life was possible in worlds different from ours, both in the Solar System and others, and after so much time it had at last been fruitful.

It turned out that not only one, but two of the worlds in that remote system bustled with life. The lines in their spectra were clear, unambiguously showing the ingredients that formed their atmospheres, but the interpretation of these compositions was at first disturbing: there was no way in which known or predicted geological or inorganic processes could support such a chemical imbalance. Despite the fact that the existence of extraterrestrial life was the simplest explanation for this phenomenon, finding it for the first time in history in such abundance and with that level of development was something so hard do accept by human mentality that years of verifications and discarding of alternate proposals were needed before claiming the discovery as definitive. But once done, and when the shock and incredible initial agitation were overcome, the news were accepted more as a confirmation than an unexpected finding. Just like the discovery of the first extrasolar planet in the last years of the previous century, this one had been preceded by decades of tales and stories in which it was taken for granted, waiting for improvements in the instrumentation to have the evidence on its side. Earth was not unique in the Universe.

This discovery, however, brought consequences that were still hard to assimilate. The relative closeness of the star, at just a blink of an eye in cosmic scales, together with the exuberance of its system, seemed to support the hypothesis that life was spread out all over the galaxy. Would it be possible that the closeness of two solar systems with life so prosperous was just an incredible statistical anomaly? It seemed unlikely. And that's how it was reflected in space developments in the years after. New orbital telescopes with greater capabilities were launched, carrying out a thorough scrutiny of the sky in search of other worlds full of evolutionary possibilities. Some candidates would be found in the course of time, but all of them were far from being so clear and conclusive. Meanwhile, improvements in the instrumentation and new interferometers permitted to continue studying that first system, in which the measurement of radial velocity, its light curve and even direct imaging made it possible to discover a couple of extra outer gas giants, and to refine the orbits and sizes of the planets already known.

While the space agencies took advantage of the renewed interest to obtain better and needed funding, and astrobiology got revolutionized thanks to this by studying the first known data of what was its true field, the amateur astronomers community grew enormously. Many were those who wanted to take a look at this star, and with an ever increasing number of people in possession of equipment as good as those of modest professional observatories just a decade before, the available data about this neighbouring system were abundant.

It was the best of these data, together with the last advances in the professional observation technologies, what would help solve one of the small mysteries that arose in this system. Sometimes there were detected what seemed to be transits of lone objects the size of planetary moons, which we were starting to be able to observe, but didn't correspond with any Doppler shift of the star in consequence. Among other things it was speculated that they might be small sunspots, but their crossings in front of the bright star were too short-lived, and they didn't have the variability expected of something like it. However, what could be measured was that the way in which they hid the light of their sun showed deviations of what would be expected if these bodies were spherical. Suspicions by the scientific community, to whom it was harder each time to be cautious before jumping to conclusions that could be described as exotic, increased over the years, as another characteristic shown by a subgroup of these objects was confirmed. In a way not explainable with gravitational interactions, their orbits had varied noticeably between a transit and the next.

Scientists were not wrong when they changed the way these objects were named. Gigantic structures, the origin of which could not be natural, were orbiting that system. And some kind of civilization was using them.

One could only speculate about the role those structures might play, but there was something clear. We were faced with a sign of extraterrestrial intelligence, and with a technological level more advanced than humans', visible on our instruments. The news touched something sensitive in the spirit of humanity, and questions multiplied. Would they know about our existence? It was not very probable. The last light that would have reached them from our system, from which it departed more than a century ago, would have barely started to show the intense changes our species would cause on the planet later on. Furthermore, it was impossible to see a transit of the Earth and the Sun from their position, so studying the characteristics of the abundant terrestrial life was more complicated, but maybe for their technological level these were not big challenges. However, despite all this, the fact that captivated more minds and appeared in many more headlines was something different —if they were not lost among the variations of background noise, our first radio, radar and television emissions would reach their system in just a few decades.

Would their hypothetic inhabitants be able to receive and interpret these signals? And that being the case, would there be an answer? Could we be receiving the first extraterrestrial transmission after a wait of less than two centuries? There were people who thought we could, and if the advances made to fight aging continued developing at this rate, some might get to live through it. And they wanted to see it. It was true that a discernible radio signal had never been received from that system, but humanity itself was ceasing to be detectable in those waves with the change to digital transmission languages. Something similar could have happened there. In the background, however, there was a more important matter. In the same way as we could only be seen as we were a century ago, the light arriving to us from that system had an identical delay. Who knew what the technological level of that civilization would be when they became aware of our presence. If they had developed interstellar travel, it was even possible that an encounter could take place in the future. In what position would we be? It was clear that they had a great lead over us, enough so that they would not find it hard at all to subjugate or eliminate us if it was considered convenient.

However that didn't intimidate us. Quite the opposite, space technology started to develop with a greater boost than the one initially provided by the discovery of extrasolar life. Maybe it was this kind of competition never oficially proclaimed, but present as a possibility in the thoughts of many people, what had been missing in the previous decades to make human beings spread among the Solar System. In a short period of time the number of missions and space stations increased, and the Moon was set foot on again, aiming to establish permanent colonies on it. But the most important of all was the degree of international collaboration that was being achieved in these projects. It seemed that the great discovery of a different civilization had another effect in human perception —self-consciously or not, we assumed the concept of humanity as 'our civilization', to which we all belonged without distinction. The clashes and old rivalries between powers were apparently being pushed into the background, in the face of the mutual progress our species was achieving in this insignificant corner of the Cosmos. And the advances were remarkable. Space colonization had repercussions with improvements in the living standards, while the pressure on the precious ecosystems on Earth started to diminish. Human beings set foot on Mars, and microbial life ended up being discovered in the red planet, so close but paradoxically never seen until then, strengthening the conviction that life was abundant all over the galaxy. More missions to search for it in any form were sent to Venus and the outer planets, as a display of the optimism resulting from having found it spread among the stars.

While humanity developed its own space structures in the form of habitats, power stations and solar sails, it kept its eyes on the sky. The star that started everything was constantly scrutinized to see what else could be learned from their inhabitants. Photometric techniques were already allowing to even obtain rudimentary maps of their planets' surfaces, and there was even a serious proposal to send a big space telescope to the place where the Sun's gravity focused the light of that distant system, which would enable us to analyze it with an unprecedented level of detail.

And the fact is that there was a lesson learnt while observing the movements of those beings. A lesson maybe more important than any other, and with an influence that was felt in many of the great events of those last years. A lesson that filled with hope a species that had lived in the uncertainty of the possibility of self-destruction in the previous century. To be able to see a much more advanced civilization prospering in another system was proof that the technological adolescence that several times was close to exterminate our culture could be overcome.

Our survival, and the expansion of our legacy throughout the Cosmos, were possible.


Further reading:

The Extrasolar Planets Encyclopaedia

Eureka: Sistemas exoplanetarios

How lucky would Kepler have to be to see us?

The far future of exoplanet direct characterization

Neil DeGrasse Tyson on the possibility of detection of Earth's radio signals

La Orilla Cósmica: Velocidad de escape de la longevidad

La Orilla Cósmica: Salvar la Tierra colonizando el espacio

Entradas en La Orilla Cósmica sobre colonias y hábitats espaciales

La Orilla Cósmica: IKAROS y LIGHTSAIL (Velas solares)

Eureka: Mapas de otros mundos

The FOCAL Mision: To the Sun's Gravity Lens

Eureka: Cómo detectar vida más allá del Sistema Solar