(My sources are cited at the bottom of this article. For much of this article, I researched the content put out by Isaac Arthur, who in 2020, was named the recipient of the National Space Society’s Space Pioneer Award for Education via Mass Media)
Mercury is one of the most neglected planets in Science Fiction. Mars or Venus are usually the sites for fictional colonization. One might think Mercury’s close proximity to the sun and its lacking atmosphere would make it a dud.
But there are actually several reasons why an airless ball of silicon and metal next to the sun could have potential.
Below I will include resources that could be helpful to science fiction writers.
Since people don’t commonly write about Mercury, it would be a great way to come up with something unique that would make their work stand out.
MERCURY’S LONG TERM POTENTIAL AS A DYSON SWARM
In the long term, Mercury could be used as a building supply store to construct power collectors, and then disassembled to form the basis of a Dyson Swarm.
A Dyson Sphere is a megastructure that completely encompasses a star and captures a large percentage of its power output. The thought is that this would be how a space fairing civilization would meet its energy requirements, exceeding what could be provided by planets alone.
A Dyson Swarm is a variant that consists of a large number of independent constructs (usually solar power satellites and space habitats) orbiting in a dense formation around the star.
However, turning Mercury into such a structure would take a very long time. Longer than the longest human civilizations have existed. Human beings don’t seem capable of dedicating themselves to such a long-term endeavor, but some kind of AI-human hybrid with a super long lifespan might. So if you decide to write a story about a people turning Mercury into a Dyson Swarm, you might also want to make them into something more than human.
BENEFITS OF COLONIZING MERCURY IN THE NEAR AND MIDTERM
What about Mercury’s near term/mid-term colonization potential, in case we don’t want to wait for the time span of several civilizations for it to become useful? What are the benefits?
The proximity to the sun presents potential for harnessing a tremendous amount of solar energy, collecting solar energy for both Mercury, and other planets in a colonized solar system. This could be achieved via orbital solar arrays, which would be able to harness energy constantly and beam it to the surface. This energy could then be beamed to other planets in the Solar System using a series of transfer stations positioned at Lagrange Points.
A Heavy Metal World:
Like Earth, Mercury is a terrestrial planet, which means it is made up of silicate rocks and metals that are differentiated between an iron core and silicate crust and mantle. However, unlike the Earth, Mercury’s composition is 70% metal. As a result, if Mercury were to be mined, it could produce enough raw materials to supply humanity indefinitely.
Similar Gravity to Mars and a Low Escape Velocity:
The gravity on Mercury is 38% that of Earth, which is similar to what Mars experiences. This is twice the level of gravity of the moon, making Mercury easier to adjust to than the moon. The low gravity coupled with the lacking atmosphere (no air drag) also gives the planet a low escape velocity, making it easier for ships to escape Mercury, in that they’d require fewer resources to do so. This would make Mercury a great site for exporting materials, especially considering their wealth of metals. Also, it would make Mercury a great site for building ships, especially if human beings become an interstellar civilization. If stellar lasers were built near the sun, a vessel could be launched from Mercury and pushed by lasers out of the solar system. And hydrogen for fuel would certainly be plentiful given the solar winds blasting Mercury.
Proximity to Earth:
As a resource-rich world, Mercury is closer to Earth than the Asteroid Belt or Saturn. Mercury also achieves an inferior conjunction (the point where it is at its closest point to Earth) every 116 days, which is significantly shorter than either Venus or Mars. Basically, missions destined for Mercury could launch almost every four months, whereas launch windows to Venus and Mars would have to take place every 1.6 years and 26 months, respectively.
HOW TO MAKE COLONIZATION ON MERCURY WORK?
Mercury is the closest planet to the sun. Therefore, we tend to think of it as the hottest, but Venus actually beats it for peak temperature. Also, what many people don’t expect is that Mercury can get very cold. Mercury gets downright cold at night, unlike Venus, since it has no atmosphere, just a thin haze of mostly hydrogen and helium from the captured solar wind.
One way to avoid getting too hot or too cold is to set up mobile bases. These mobile bases would chase terminator, so Mercurians can get some solar power, but to where it hadn’t heated around or cooled down that much.
People would set up their camps where it’s cool and move on when the light and heat are too much. They would drive ahead to someplace that’s cold. But not so cold that they couldn’t work there. This would be good for mining.
An example of this in science fiction is what people did in Dune when they were avoiding giant sandworms while harvesting the Spice Melange.
People living in mobile bases would need to set up backup vehicles and engines in case one died. And they could use the extra energy from these backup vehicles while moving in order to power smelters and refineries.
Heating things up on Mercury to smelt them wouldn’t be too hard. A solar oven would work quite well because of the proximity to the sun and the fact that there are are no clouds in the atmosphere.
Mercury’s night side is also a good place to get rid of heat—something hard to find anywhere else near the sun. If one is generating a lot of heat, they can only get rid of that by radiating it away.
Down on Mercury’s light side, people could use conduction too, so they might have mobile factories at work, not just mining and refining operations.
The Great Flat Track of Mercury:
China has the Great Wall. Mercury might have the Great Flat Track.
As I mentioned earlier, getting what you want off of Mercury wouldn’t be that hard. The planet has an escape velocity of just 4.25 km/s, and an orbital velocity of just 3 km/s. It has no air. If Mercurians had a flat track from where vehicles could take off, without having to worry about air drag, leaving would be easy. However, landing would be hard. (A sort of opposite Hotel California situation, where it’s easier to leave than arrive).
Since there is no air, ships cannot aerobrake to shed velocity for free. Though one might be able to hit a very long track, very precisely and slowly shed speed off without friction, or run down a magnetic tube to let it leach off speed.
This gives Mercurians good reason to consider building a track all the way around Mercury, and it need not be at the equator either if people wanted to keep it shorter. Mercury gets hot, but is still cool enough for many metals to handle. Even steel, which is fairly mundane considering some of the materials Mercurians might use, retains its magnetic and conductive properties at those temperatures, and one thing Mercury is not lacking in is metals. Though one’s concern would be metal fatigue, as metals are expanding and contracting to various degrees as they run up from temperatures cold enough to liquefy air to hot enough to melt lead, but this is happening once a Mercurian day, which is very, very, very long (it takes 59 Earth days to complete one rotation on its axis Universe Today). So the Flat Track would not be getting heated and cooled constantly, and even today we know a lot of tricks for various alloys and composites that would minimize metal fatigue.
The Planet Down Under:
If one digs down a little bit on Mercury, they would start to see livable human temperatures underground, once they get away from the craters and closer to the poles, and in one of the more optimistic models, even room temperature underground at the equator at 90 degrees west, which would help with the expansion and contraction fatigue and other construction problems caused by varying temperatures.
If one doesn’t want to use mobile bases or live underground, they could try mushroom habitats.
These habitats would have a retracting option, where things fold down during the night and the brighest day, and pop back up when things are more moderate.
The habitat would be built up on stilts that aren’t thermally conductive. Then one would put a big umbrella over it, covered in mirrors, to bounce light away, one that could flip open or move aside to let in however much light a person wanted. Stilts would be made of something that doesn’t conduct heat well, like the silicate beneath the ground. Spinning habitats could use centripetal force to create Earth-like gravity in the habitat.
Water in the Poles:
There could be some water at some of the craters near Mercury’s poles. Wires underground could bring the water to people.
Making Mercury Earth-like:
One doesn’t have to make a planet like Earth, if they want to live there.
But if people did want to make Mercury Earth-like, massive mirrors and shades in orbit could help cool down the planet. Mercury is massive enough to hold a breathable atmosphere. People could also collect solar wind from the sun, rich in hydrogen and helium, things that could be sold, using a giant mirror or shade acting as a giant windmill driven by the solar wind. “Star Wheel.”
MERCURY IN SCIENCE FICTION
As I stated, Mercury isn’t mentioned frequently in Science Fiction, which is why it would be a great thing to write about. However, if you do want to read some works that mention a colonized Mercury, check out the works below.
Sundiver, in David Brin’s Uplift Saga.
Singularity Trap, by Dennis E Taylor
The Sirens of Titan, by Kurt Vonnegut, Jr.
Blind Mystic, by Jessica Brook Johnson (Short story)
Runaround, by Isaac Asimov (Short Story)
Retrograde Summer, by John Varley (Short Story)
The Coldest Place, by Larry Niven (Short Story)
“While working almost forty years” (Short Story on Fandom.com)
MORE INFORMATION ON MERCURY IN FICTION
Science and Futurism with Isaac Arthur
How Do We Colonize Mercury? (Universe Today)
Colonization of Mercury (Fandom)
What Would It Be Like to Live on Mercury? (Space.com)