Just Us…?

Exoplanets have been found in the Orion Nebula (photograph by Chirag Sagare)

4.5 billion years ago, a cloud of fiery dirt formed in a zone around our star, the Sun, called the Goldilocks or habitable zone. About 3.7 billion years ago life appeared and evolved to eventually call the ball of dirt, our planet, the Earth. Now, according to the big bang theory, the universe formed approximately 13.8 billion years ago, and our Earth was born only 4.5 billion years ago, which means the Earth is relatively young. There are around 10 million clusters of galaxies in the universe with each supercluster typically containing 500 to 1000 galaxies. Now, on an average, a galaxy has around hundred billion stars with a large number of planets and their moons in their respective systems. It only makes sense to think that there have been many others before us. There must have been more planets in their own Goldilocks zone, right?

The Fermi Paradox

Let’s go back a few hundred years, to the 1760s. This was when the first
industries appeared; this was when humans stopped and thought it was
about time they created machines to ease the work for humans. Eventually dawned the age of industries and machinery, and our eyes started wandering among the stars with the motive of colonizing space. It took us just two centuries to develop from making machines to travelling to space in one. This should make us wonder, if we could do it then what about the other planets that have been around longer than young Earth? Shouldn’t life already be out there? Shouldn’t outer space already be teeming with intelligent life?

The Great Filter

It is a hypothetical barrier which alien species (and us) would have to cross, in terms of technological advancements and their safe implementation, to be deemed as intelligent life. It is a filter, where the life before it might just be approaching destruction, and life that crossed it has passed the stage and has the capability to continue developing and expanding across galaxies. The problem is that we cannot predict where the filter exists- ahead of us, or have we left it behind.
What about the rest of the planets? Has intelligent life on those other planets crossed the filter already? Are we only approaching it? Is that why we don’t see others among us or is it because they overused their technology to the extent that led to the end of their existence; have we already crossed it, leaving them behind? There’s no true answer to any of these questions, and they remain a paradox. This is called the Fermi Paradox.

If we have indeed passed the Great Filter, then that leaves us alone in this vast unscalable universe. When we look up at a starry sky, we see this.

Did you know, all of these stars we see up there are just from a minute portion of the Milky Way galaxy? The blue highlighted spot is the neighbourhood consisting of more or less all the stars visible to us in the night sky.

Artistic rendition of Milky Way ( Source: Nick Risinger)

That’s how big our galaxy is, which is just one of the billion others. It makes us all seem very insignificant in this gargantuan universe. We humans, with all the work and effort put into space travel, have been able to build the technology to reach a distance of roughly 21 billion kilometres over nearly 45 years with the Voyager 1 spacecraft. Imagine what other intelligent species out there could have been capable of accomplishing in the eleven or so billion years that we weren’t around. It only makes sense to consider that alien life does exist out there. We cannot be the only life there is. Just this thought makes man, a social animal, paranoid, and over the years there have been many unidentified sightings of aliens and UFOs and whatnot.

We have made efforts to establish contact with extraterrestrial life with the golden disk records on the Voyager 1. It has information on all the life on Earth, with diagrams on the discs to explain its use to any extraterrestrial life, if they were to encounter the Voyager in its interstellar voyage.

Thinking otherwise, a problem arises. What if alien life is not how we expect it to be? What if they didn’t have two hands or two legs or two eyes? Alien life could be trapped under a layer of ice or stuck underground, and we would be merely scratching up the surface of whatever planet we land on, not finding anything. Aliens could be stuck on a Super-Earth (a Planet with Earth-like conditions just much larger) and so, life would need to achieve a speed of nearly twice the escape velocity of Earth thereby making space exploration a distant dream to them. Whatever it is, though, we may never know. Yet, we continue to explore outer space with the hope of finding life of some sorts out there, and if not, just evolve into a multi-planetary species.
We continue to speculate and hope to find life in systems like the Alpha Centauri star system, where some planets exist in the habitable zone around the twin stars. There have been programs, to experiment in the waters on a few of Saturn’s moons, like Titan and Enceladus, and some others to research Venus’s ability to host life. There are so many activities caught on our telescopes, such as randomly accelerating unidentified objects, geysers from moons shooting into space, etcetera, and every one of these activities could indicate that we are not alone. And if all of this was just within our reaches, what about all those other stars in our galaxy, in the next galaxy? With a little coordination and proper direction into space, we can spend our capital wisely enough and find answers to all of these questions in the decades to come.



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