Our ability to detect things lights years away from us seems to be increasing in leaps and bounds. Scientists are predicting that it will be only a matter of time, perhaps as soon as five years, before they are able to say they’ve discovered Earth’s twin, another planet in another solar system, circling another star, capable of supporting some form of life.
Momentum is building: Just last week, astronomers announced they had discovered three super-Earths — worlds more massive than ours but small enough to most likely be rocky — orbiting a single star.
Not bad. Three solid planets in one system. Apparently, since the 1990s, they used a detection method know as the radial velocity method, which looks for the interaction of the gravitational tug of the circling planet on the star. But with a new method, known as the transit method, they detect a slight change in the light of the star they are observing as a solid planet passes in front of it.
Both methods are limited by their ability to block out the overshadowing light of the host star. For instance, the sun is 100 times larger, 300,000 times more massive and up to 10 billion times brighter than Earth. “Detecting Earth in reflected light is like searching for a firefly six feet from a searchlight that is 2,400 miles distant,” writes a panel of astronomers recently in their final report of the Exoplanet Task Force.
With the hundreds of billions of stars in the observable universe, it’s becoming more and more of a statistical certainty that there would be other planets capable of forming and sustaining life. The type of life is still up in the air, but it would be life nonetheless. The fact that life spontaneously arose on this planet (as seems to be agreed by the prevailing theories, save one, and we try not to call that a theory) seems to point to the obvious conclusion that it could and probably did happen elsewhere. Given the fact that most of the matter in this solar system seems to be present in the rest of the universe, that this solar system arose out of common matter found everywhere, and given the immense passage of time involved, it is inevitable that life as it arose on this planet could also arise on others under similar circumstances.
I wasn’t aware of this, but you learn something new every day:
…computer models have shown that plate tectonics, the forces that move continents and lift gigantic mountain ranges, are key to life on Earth as we know it, and possibly to life on other worlds. That’s because as the rocky plates that form the planet’s outer shell move about, they also recycle carbon dioxide. This greenhouse gas keeps our planet’s temperature balmy, but not too hot. And the telltale signal would be certain levels of carbon dioxide, suggesting that just as on Earth, this other world relies on plate tectonics to cycle carbon.
The Earth is so infinitely complex, with so many systems and sub-systems needing such precise balance to continue to support life, it’s no wonder it took us thousands of years to understand it all, assuming that we fully do, which I doubt.
So let’s assume that we will ultimately find this doppelgänger. So what? What good will it do us, one might ask. Especially those who believe that we are the center of the universe, and whose core beliefs would be seriously threatened if we found another Earth-like planet.
My answer, and it’s certainly not the best one, is that this is what we do. We constantly stretch our minds in the search for knowledge. I personally would be quite heartened to find that there is another planet out there like ours, because one of my core beliefs is that we are not special, that we are not the center of the universe, and we are not some god’s chosen people. Wouldn’t it be nice to know that the formation of a planet with tectonic plates, recycled carbon and an atmosphere capable of supporting life actually existed light years away from here? Wouldn’t that confirm the natural explanation that such a planet could easily form, by itself, out of the stuff of universal matter, as an almost evolutionary process? Wouldn’t it tend to confirm that this planet we call home is the result of natural processes common to the universe, and not a special act of god?
I think so.