I hope you are all safe and doing well.
Glancing at the title of this post, you may be confused. “Pranet!” you say. “This is supposed to be an astronomy blog! Why are you talking about something that is so inherently terrestrial?”
And to that I respond, “But is it?” *cue dramatic music*
Very recently, a shocking discovery made waves throughout the astronomy community. Liquid water had been discovered on the surface of the moon.
Now, this is an absolutely incredible revelation. Starting from the discovery of water on Mars in 2015, this continues the trend of its discovery on close (relatively) to Earth objects harboring that life-nurturing self-sustaining ambrosia. It is especially exciting due to the ramifications that it has for not only the potentiality of extraterrestrial life but also for the possible benefits this could have for humanity.
But I’m getting ahead of myself.
In this post, we’ll be taking a step back and talking about the various discoveries of water found on extraterrestrial worlds (which I’ll be calling alien water from now on) and the potential these have for the future.
So sit back, relax, and enjoy the ride!
Water is the most essential commodity (other than air, of course) to human survival. It is an integral part of maintaining cells’ health. Humans can last around 3 weeks without food but will die in 3 days if they don’t get water.
As a result, when thinking about space missions, water is an important consideration to make. Water is not a very light substance (try carrying around a gallon of water everywhere you go!) and as weight is highly prioritized in any spaceflight, this makes any wastage of water a considerable liability.
Science fiction has explored methods for water in space considerably. In Andy Weir’s 2011 novel The Martian, humanity’s base on Mars has a water reclamation system that pulls water out of the air for reconsumption. The International Space Station also works on this principle, essentially creating a mini water cycle. The less existing water that is lost, the longer you can go without a resupply mission, which means less cost, less weight, less fuel, and an overall improved interplanetary experience.
Water, being the fuel of life (and containing the fuel for rockets!), can play two important roles in space. Not only can it act as a potential home for extraterrestrial organisms (mostly uni- or multicellular), it can also be an essential reservoir for any of humanity’s interplanetary (or maybe even interstellar!) travails.
Let’s talk about the former first.
Alien water has, of course, the potential of harboring alien life. This makes the discovery of watery worlds tremendously exciting.
There’s a primal emotion, a nugget of inquisitiveness, in every single one of us regarding the potential discovery of alien life. No matter whether we visualize a friendly ET or a horrifying Xenomorph, this idea has dominated humanity for a long time.
So what if I told you that there is a world in the solar system that has oceans of liquid alien water?
Europa, one of the four major Galilean moons. A seemingly inhospitable body of ice.
However, it harbors a liquid paradise within.
By studying the movement of ice on the surface of Europe, scientists were able to deduce the viscosity, volume, and composition of the fluid that it rested on. And lo and behold! Their science was able to prove that the fluid that the ice rested on was, in fact, liquid water!
This caused tremendous amount of excitement in the astronomy community.
“But wait!” you may be saying. “Europa is so far away! There’s no way that it can sustain life!”
Now, here’s the interesting part. Even on Earth, during the depths of winter, fish can survive in mostly frozen lakes. How?
Essentially, the ice covering on top of the lake forms a sort of heat shield, preventing the water farther down from freezing all the way. So no matter if the temperature on the surface of the lake is inhabitable for fish to survive, they are able to survive quite comfortably under the ice. Here’s an example of such a lake on Earth:
Credit: Science News
The natural implications of this understanding is that there could, potentially, be some form of unicellular or similar life under the ice on the surface of Europa. If we were able to send a probe to go through the kilometers-thick ice, who knows what we’d find?
Now, let us discuss the second impact that alien water can have.
As we discussed earlier, long space missions need water. It’s an unalienable (no pun intended) necessity. So wouldn’t it be great if on long journeys, there were refueling stations along the way?
Further, if we were establishing a colony anywhere other than our planet, we would need a source of sustainable water.
The beauty of water is that it is essentially two hydrogen atoms and one oxygen atom bonded together. Rocket fuel relies heavily on hydrogen. So if you have water, you can make rocket fuel!
Establishing a colony on the Moon or on Mars, where water has been demonstrated to exist, can therefore be done more easily, with that precious resource on hand for both human consumption and to propel us to greater distances in the horizon.
The next time you drink a glass of water, think about its impact. This colorless, odorless liquid, the stuff of life, will be among the most important necessities in the extremes of outer space. The discovery of this in outer space could mean the existence of life independent to ours. It may even be a driving force (quite literally) in our interplanetary and interstellar expansion.
So drink up! You have the future in your hands.