It’s a small galaxy: exoplanets and red dwarfs

By Trevor Busch
Taber Times
tbusch@tabertimes.com

Long before the origins of recorded history, homo sapiens has looked up and pondered the abyss of space with a primal questioning about our place in the universe. This questioning is one of our habitual instincts that is at the very root of our success as dominant predators: curiosity, the quest for knowledge, our inherent desire for discovery — all can be traced back, to a greater or lesser degree, to our primitive awakenings as an intelligent species, our hunger to learn about the world around us.

This curiosity, our intelligence, made us far more formidable than any of the other contenders for the evolutionary lottery that eventually brought us to the dawn of the modern age. As we reached out across our oceans, forged through lakes, rivers and mountain passes, with each passing decade filling in more lines on our maps, humanity began to look to the stars once more, but this time armed with the twin sisters of science and technology, rather than the humble castings of the naked eye that no doubt fascinated our apish ancestors.

Out of the cauldron of a terrible conflict came some of the first fledgling technologies that would allow us to physically reach for those stars for the first time in human history. What had been designed for destruction — rockets, jets, eventually even nuclear technologies — would be adapted for a “space race” as two opposing ideologies grappled with each other for world dominance. This chest-beating example of jingoist nationalism, curiously designed to prove the favourability of one economic system over another through scientific and technological achievement, would be a hallmark of a Cold War that was often fought not on the battlefield, but on the frontiers of our solar system.

This quest would first take machines, then animals, and eventually men into the orbit of our planet. Eventually man’s reach would even come to encompass the moon, and for the first time we would tread on the surface of a barren and sterile world that was not our own, and looked back in wonder at the enigma that is man and his tiny little corner of the vast universe. We would eventually fill our skies with orbiting devices that assist us in everything from weather prediction to mass telecommunications, travelling to and fro with reusable space vehicles, and even living in space on habitable stations. Our reach has now extended far beyond our solar system, with our new technological devices probing ever outward toward the icy fringes of our galaxy.

With each passing year, we have learned more and more about the gargantuan vastness that surrounds us like an enveloping embrace. But we have yet to answer one of the pivotal questions that has coalesced in our minds since we became mature enough to ponder the seemingly unique nature of our own sentience: Are we truly alone, or are we merely one voice in a chorus of many, yet to be discovered?

We may now be on the cusp of learning something about the answer to those questions. Last week, NASA announced the discovery of a solar system with seven — that’s right, seven — Earth-like planets, with three that may exist in the star’s habitable zone. What’s even more remarkable is that this cluster of planets, in orbit around a dim red dwarf star called Trappist-1, is only 39 light years from Earth. In cosmic terms, that’s a proverbial hop, skip and jump — even though it would take 39 years to reach the system traveling at the speed of light, and what’s more, no human spacecraft has even come close to approaching that speed. Put another way, there had better be a lot of galactic service stations along the way, because at 369 trillion kilometers, the kids in the back seat will have their eternal question, “Are we there yet?” on infinite repeat. Let’s just say humanity won’t be visiting Trappist-1 for a lot of decades yet to come if we’re still utilizing present spacefaring technologies.

Not the first exoplanets (as they’re now referred to) to be discovered in recent years, the galaxy suddenly seems to be coming alive with potential candidates for the first Earth-type habitable planet outside our solar system to be discovered in human history. Scientists now tell us that untold millions of these planets could be lurking in the “goldilocks zone” — not too hot, and not too cold — of these planetary systems throughout our galaxy. You do the math: if there are, by most estimates, 200 billion stars in our galaxy, multiply this by 10, and you’ll have a rough estimate of the number of Earth-size planets in the galaxy. That’s a lot of potential life-supporting real estate out there floating around.

And while exoplanets are no longer unique, what has shocked and awed scientists and science fiction fans alike is the proximity of this system to our own, despite being a distance that in common Earth terms still staggers most imaginations. That’s a mere fingernail in terms of the wider galaxy, but to help understand the utter vastness of space, here’s a little perspective. The fastest outward-bound spacecraft yet sent, Voyager 1, has covered 1/600th of a light-year in 30 years and is currently moving at 1/18,000th the speed of light. At this rate, a journey to Proxima Centauri — the closest star to our own — would take 80,000 years.

Scientists and engineers still dream, and many of their ideas for interstellar travel are fast becoming more than just pie-in-the-sky (no pun intended) attempts to rationalize science fiction. Still, necessity is the mother of all invention, and the discovery of a habitable world within reach of our own would probably stir in us that age-long instinct for exploration and discovery that is so deeply rooted in our nature as a species. We would be tempted to achieve what we can conceive (to loosely quote Jules Verne) and to reach for what our imaginations have only humbly prepared us.

Still, should we never develop the transportation technology to easily and quickly take us to neighbouring worlds and systems, there are still options. A popular one in science fiction is the concept of a “sleeper ship”, where passengers are placed in a deep stasis and automated machines run the ship for the centuries it may take to reach another star system, where the passengers are then woken up, albeit to inhabit their new world. It’s the pseudo-technology that centers prominently in the Alien science fiction films, among many others.

Another concept that has been explored in films like Interstellar is the idea of “seeding” other worlds with a sort of genetic milkshake, some kind of an automated humanity-conceiving machine that could be shot out from Earth via satellite to only arrive at its destination perhaps thousands or tens of thousands of years later. Seemingly far-fetched, the idea actually carries a high degree of merit, and might eventually be the only way our species survives in a few billion years when the great beating heart at the centre of our solar system exhausts itself and inevitably destroys all that we have wrought.

There are some of us, however, that will not want to acknowledge the existence of life elsewhere in our galaxy, even if we someday find it, or it finds us.

For many, alien life would/could contradict some of humanity’s most cherished and revered beliefs, prominent among them many religious denominations. It is not too strong a statement to suggest that for some the discovery — certainly of intelligent life, if not simple lifeforms — would call into question the very existence of God. Others, perhaps the more pragmatic, would simply suggest that His myriad canvas was much larger than we ever gave Him credit for. However, it is impossible to predict how unpredictably mankind would actually react when confronted with the idea that they might not be the culminating achievement of a benevolent deity, but only brothers and sisters in a vast cosmic family. The very idea, in and of itself, squashes a man’s ego.

Located in the constellation of Aquarius, Trappist-1 is barely the size of Jupiter. Its seven planets circle the ultracool star in orbits that would fit inside Mercury’s orbit in our own system. That’s incredibly close to the star’s surface, but Trappist-1 would shine with an intensity 200 times dimmer that our own sun, so if you were standing on the surface of one of those planets, it would take on a reddish-salmon glow, complete with high-intensity UV radiation. Probably something like the beaches of Tahiti during a tropical sundown, but unlikely to be anywhere any of us would like to go on holiday. And you can forget any Polynesian beauties bringing you frigid libations.

But considering the handle that has been applied to this star system, there’s always the possibility you might run into a few far-flung Trappist monks brewing beer with exo-water and alien barley. Ahh, that space-fresh taste! Nothing quenches the thirst of an interstellar journey like Trappist Light…

Now that sounds like a planet worth visiting.