With Love, To The Moon
It's night time. Work is over, dinner has been eaten, and you're just about to go to bed. You lay down for a short while, but your mind decides it's not done with the day just yet. You think you let ideas run their course, but you are still not tired. You decide to pull the curtains to welcome the night sky into your room.
It's bright outside; the sky is radiant. You notice, but only barely, as your eyelids slowly start collapsing under their own weight. You start drifting away, and just as you are about to close your eyes for the night, you glance upward. It's the moon—our moon—a celestial constant in an otherwise ever-changing sky. Under its glow, you fall asleep, reassured that no matter what, the moon will be there all night, just as it has been for millennia.
Our moon has pledged its allegiance to Earth for a long time now, almost for as long as the Earth has existed, by some estimates. But this loyalty has not always been rewarded with the attention that it merits. The moon and its understated presence, both in the night sky and in our ambitions of becoming a space-staring civilization, have been gathering the limelight as of late. Not one, but two major developments regarding the moon in the short span of a month.
On October 26, 2020, NASA's SOFIA, short for Stratospheric Observatory for Infrared Astronomy, discovered the presence of water on the sunlit surfaces of the moon. Now, while the presence of water on the moon is not surprising news, any significant amount detected thus far had only been in the darker, shadowed parts of the moon. By the way, the moon has no dark side; all the sides are lit. But it just so happens that the moon is tidally locked to the Earth, which means that we see the same side of the moon every night.
It has, however, poles. It is in these poles that water was previously discovered. These poles were able to source some water because they were protected from the otherwise extreme temperatures on the rest of the moon's surface. The lack of an atmosphere means that temperatures on any given lunar day can fluctuate by more than 200 degrees Celsius. That meant that whatever water that could have been on the moon would quite easily just evaporate off.
This is why the presence of water on the sunlit surfaces comes as such a surprise; it's where you would least expect to find it. The amount of water is still minuscule, even when compared to the water content of some of the harshest deserts on Earth. Yet, the mere fact that there seems to be a mechanism that is generating or at least storing water is of great significance in humanity's next chapter in space exploration.
On the other hand, China's Chang'e 5 spacecraft launched moonward on November 23, 2020. Its mission is to try and understand the history of the moon by bringing back lunar rocks that are younger than any of the samples we already have. The samples that are supposed to be brought back are a billion years younger than the ones collected by Apollo. Scientists intend to study the late-stage volcanism that should answer questions about the moon's younger surfaces.
It's a short 23-day mission, after the end of which we should have a clear picture of how our rocky neighbor came to be. This mission is one of a series of missions that, in theory, should culminate into the International Lunar Research Station in 2030. But given how close the moon is, it's actually quite surprising how we still do not know so much about it.
For one, we're still not totally sure how it was formed. We have theories, of course, the likeliest of which is a spectacular one. According to it, the moon was the result of a collision between the Earth and a Mars-sized planet named Theia. The impact from the collision ejected material that eventually morphed into what we see today as the moon. This theory seems most likely because the composition of lunar rocks brought back from the Apollo missions is very similar to what can be found on Earth, suggesting they were from the same source.
There are theories still about whether that initial collision led to the birth of just one moon or two. This is because the crust on the moon is not even; parts of it are significantly thicker than others, and scientists believe that it could have been caused by a collision on one side that led to the uneven thickness. Regardless, the moon was far from the gentle orb of light we see today. Soon after it formed, it was a fiery ball of magma.
But even at its hottest, most ravaging state, our cosmic companion was already preparing Earth to harbor life. You see, like how the Earth tugs on the moon, the moon too tugs on the Earth. The gravitational pull goes both ways, and as such, soon after the collision, the moon's pull would help to stabilize the Earth's axial tilt, allowing the seasons to exist. Had it not been this way, we would have had a barrage of ice ages and extreme warm climates all at the same time.
This axial tilt and its consistency are down to the size and number of the planet's moons. In fact, the Earth is the only planet among the eight major ones to have one moon. Mars, on the other hand, has two, but both are rather small, and as such, Mars' axial tilt is about 10 degrees from its normal tilt of 25 degrees.
We also have the moon to thank for stirring up the primordial soup with its power to influence tides. Without that, organisms may have never amassed enough nutrients to form into complex life forms. In the early days, the Earth was spinning four times faster than it does now, but over time it slowed down to the 24-hour days we have now.
But why is there an uptick in talks about the moon lately? Well, for starters, there's the Artemis program, which is an incredibly ambitious program that intends on having the next man and the first woman on the moon in the next five years. While we've already been to the moon, this time scientists seek to learn how these astronauts could spend prolonged periods in space to be better suited for longer space travel, such as the subsequent colonization of Mars.
You see, in the scale of outer space, the moon is really, really close. Given we have already visited it numerous times already, it's quite surprising that we haven't visited it again in such a long time. Recent discoveries, though, stir up some much-needed excitement about the moon. While it has been overlooked in the past few decades, having a colony on the moon is the next logical step in our space endeavors.
Water is obviously one of, if not the biggest concern in having a stable presence on the lunar surface. Now, this is important for both drinking and jet fuel. Jet fuel contains the very same ingredients as water: hydrogen and oxygen. The recent discoveries certainly shed some optimistic light on the possibility of using this water, but scientists could also use the solar wind and the hydrogen that came with it and combine it with the oxygen found in lunar dust. This would give us even more fuel to bunny hop around even further into the solar system.
Speaking of solar wind, we also need to think about protecting ourselves from the harmful radiation in space. Solar wind is essentially charged particles from the sun that are constantly being ejected into space. They move extremely quickly and are upwards of one million degrees Celsius. Particles don't sound dangerous, but the radiation most definitely is.
It's no wonder then that the astronauts who have been to the moon have shorter life spans than their earthly brethren. Besides, one of the reasons you see so many craters on the moon's surface and not so many on ours is that the moon simply is not big enough to hold onto an atmosphere so that asteroids will burn up on entry. It's also why there's no insulation on its surface, which is why you see the crazy 200-degree temperature differences between day and night.
All these things pose a significant risk for a future colony on the moon. You and I take our atmosphere for granted every day, but had it not been there, even something as small as an intergalactic grain of sand would have the velocity many, many times that of a bullet and could cause a lot of damage.
All of this has led scientists to consider lava caves as a possible place to live. When the moon was still an act of fireball, lava seeped through some of the layers of its surface. It eventually cooled down, as we know, and lava dissipated, but the pathways it took became those lava caves. They offer protection from both the speeding debris and the temperature extremes.
The absence of an atmosphere and thermal insulation is obviously down to the moon's small size. But while the size is a disadvantage for these aspects, it is a tremendous advantage in others. The small size of the moon means that the gravitational pull on its surface is much less than compared to that of the Earth—1/6, in fact. That would mean that the same rocket will require significantly less energy to lift off from the moon than it would need to lift off from the Earth. That is why a colony on the moon is the next logical step.
Another reason why the efforts to colonize the moon can set up the scene for larger efforts later is its geopolitical implications. Conquering the moon famously became the focal point of tensions between the United States and the USSR. But beyond showcasing humanity's ability and what it can achieve when it's truly motivated, the Cold War also showed that adversaries can and do come together out of a mutual concern for their own safety and rights. Both the US and the USSR agreed to a treaty in 1967 that would allow free access and prevent natural appropriation of celestial bodies, including the moon. This law holds to this day.
Today, the adversaries have changed, yet the competition remains. While this competition should spur technological innovation, we have to wonder what its implications will be socially and politically. If there is indeed a colony, who gets to go? Who gets to live on a planet sort of void of other resources? Light is power; very few sections of the moon get regular sunlight. Who gets authority over those sections? These are social problems, not technological ones.
As such, the moon here is not so much a blank slate but a template for interplanetary policy—not just for Mars and any other planet we colonize in the future, but also for the pale blue dot we are already on right now. The moon actually moves away from the Earth about four centimeters a year. We know this because the Apollo astronauts actually left a retro reflector on the surface that scientists can point lasers to. So, it seems our companion in the night sky is leaving us, slowly but surely.
Or is it? You see, once the spin of the Earth and the rotation of the moon are equal, neither party will be tugging at each other any more than they need to remain in orbit. It is at that point that the moon will stop moving away from us. However, when all these forces cancel each other out, the solar wind remains unaccounted for. Far, far into the future, that force will cause enough drag to slow the moon's rotation so much so that it starts coming back closer to Earth.
And given enough time, it will come so close that the Earth's gravity—the endearing force that held it so close for all this time—will actually rip the moon apart. The moon will return to where it came from, but that isn't destined to happen for another 50 billion years or so. It's way more likely that the Earth will be swallowed by the expanding sun before then, and when the lights go out for one last time, the moon will actually accompany us, just as it has always done this whole time.
The moon really will be there with us forever, from the birth of life to our inevitable demise. The moon will witness all of it. The moon is our next stop; we've been there before and it's time we return. It's all about baby steps, but this is a pretty big baby step—from Earth to orbit, to the moon, to Mars and beyond. Most of us would love to be a part of that journey, and we have to start somewhere.
Luckily, Brilliant can help in turning your dreams into reality. Brilliant is helping turn people like you and I into the pioneers of the future. Topics like general relativity and solar energy aren't exactly the easiest things to grasp, but Brilliant does a great job at explaining each bit, piece by piece. Some learn better by watching, some are better with hands-on experience.
Brilliant gives you a bit of everything. With over 60 courses on science, math, and computer science, they show you what you're learning, why you're learning it, and how it's applied in real life—which is what I find I'm most concerned about. If you or someone you're close with is interested in having a big impact on the future, you'll be surprised at how easy they make it to learn.
If you are one of the first 200 people to click the link at the top of the description, you'll get 20% off a premium subscription, and you'll be able to do as many of Brilliant's courses as you'd like. Whether it's for yourself or a gift for the season, there's a lot of value there, and I highly suggest you check it out. [Music]