Every star that we see in the night sky is a sun, just like our own sun. Most of those stars have their own solar systems with planets revolving around them like our own solar system. We can see stars through a telescope because they are radiant balls of light, but exoplanets (planets outside of our solar system) are difficult to observe. Most of the time we discover exoplanets by noticing variations in the light emitted by a star as the exoplanet passes in front of it. We are too far from any other solar systems and our technology is not advanced enough to observe any exoplanets directly, which is why it is so hard to discover extraterrestrial life.
Our telescopes are improving, but they are nowhere close to being able to observe exoplanets in any detail. There is a lunar rover still sitting on the moon from the early 1970s Apollo program, assuming we actually went to the moon. The Hubble Space telescope, our most advanced telescope, is not strong enough to be able to see this vehicle and the moon is only 239,000 miles away. The closest known exoplanet is Proxima Centauri b, which orbits the closest star Proxima Centauri. This planet is 25 trillion miles away. This is why it is nearly impossible to ever discover extra-terrestrial life outside of our solar system by observation alone.
What about sending out probes to discover life? Distance poses the same problem in this situation as well. Voyager 1 is the farthest space probe from earth. NASA launched it in 1977 and it is still flying away from earth right now at 38,000 miles per hour. It took 35 years for it to leave our own solar system and is now 13 billion miles away travelling towards one of our closer neighboring stars, called Gliese 445, which is 17.6 light years away. Voyager 1 is our most realistic shot at making contact with life in another solar system. The problem is that it won’t reach Gliese 445 for 40,000 more years.
In 40,000 years humans might not even exist. Humans have existed in an intelligent state, which I define as being able to farm and raise livestock, for about 20,000 years. The first 99% of that time period was stable. But, in the past 100 years, technology has grown exponentially. 100 years ago there was nothing on earth that could end the human race. But today we have nuclear weapons, AI, genetic mutation, bio-experimentation, and numerous other things that could potentially end our race. The more potential there is for something to happen, the higher the likelihood that it will happen. What are we going to invent in the next 100 years? With our, arguably, irresponsible technological growth rate, many smart people wonder whether or not humans will survive for 100 more years, let alone 40,000 more years.
The likelihood that Voyager 1 actually makes it to Gliese 445, is slim to none. Then the likelihood that one of Gliese 445’s exoplanets actually has intelligent life and can intercept the probe and respond, is nearly non-existent. And, don’t forget that you need to add an additional 40,000 years for the time it would take for the response to travel back to Earth. The reason that I talk about Voyager 1 is because it highlights how futile the mission to find extra-terrestrial life is. This is why I don’t believe humans will ever make contact with any other intelligent beings. We are limited by time to search within our own solar system, and we already know that we are the only intelligent life revolving around our sun.
But we can’t let this depressing fact influence our opinion on whether or not we believe there extraterrestrial life actually exists. I’m not going to discuss religious arguments in this article, but I will address those in a separate article at some point in the future. For the sake of this article, I am going to assume that there is life on earth because it has the right temperature range and resources allow organic life to survive, and that something happened that triggered life to begin. I’m also going to assume that this same trigger, whether it be God, the big bang, whatever, is also capable of starting life on another planet with similar temperature ranges and resources. If you agree with those two assumptions, then you would deduce that if you keep looking at the right types of planets for long enough, you will eventually find life.
There are roughly 200 billion stars in our galaxy alone, each of which may have their own solar systems with planets revolving around them like ours. I think it is highly likely that a couple of those planets happen to orbit in that sweet spot distance range where temperature stays between 0 and 100 degrees F and allows water to exist on the planet in a liquid state. That being said, if our galaxy didn’t have any exoplanets sustaining life, then we could look at our nearest neighbor galaxy, Andromeda, which has around a trillion stars. Hubble scientists estimate that there are 100 billion galaxies in our observable universe. And, if you believe that the universe is infinite, then parallel universe theories tell us that that, not only is it guaranteed that there is other life in our universe, but it is also guaranteed that there is another version of you out there. But once again, I am getting off topic.
Try to comprehend the sheer size of just our observable universe. It took Voyager 1 35 years to fly out of our own solar system, and it won’t reach one of the next closes star in our galaxy for 40,000 more years. There are 200 billion other stars in our own galaxy, and our galaxy is a small one. Hubble has seen evidence of 100 billion galaxies, and that’s just in the part of the universe that we can see. Who knows how far it goes.
So do you really think we are the only living beings in the universe? What are the repercussions of that? If we make a mistake and go extinct is that the end of life for eternity? Arthur C. Clarke said it better than anybody else in history, "Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying".