A jewel of a planet, with some dangerous edges.

Verdant (YI-715b) is one of the first garden worlds we discovered after the Exodus; after we got settled and started looking around the corner of the galaxy that was to be our new home. The reason for the name is obvious enough. Just look out the viewport on your final approach: an orb of green, slashed with the azure blue of shallow seas. It’s the green of jungles. Verdant is a tropical planet, but it’s no paradise. If you’re going to live and/or work here, there are several things you should know first.

1) Days are short. Very short.

Verdant is big for a rocky planet, a ‘super-Earth’ as some call it, nearly twice the radius of old Earth and 2.25 times as massive. Massive compact things tend to spin rapidly. As Verdant never suffered a moon-forming big whack early in its life, it never got a moon to steal away some of its angular momentum, so the planet retains much of the frenetic spin of its youth. Days are a mere ten hours and fifteen minutes long, and with almost no axial tilt to speak of either, the length of daylight doesn’t noticeably change throughout the year. While the native life is perfectly used to the rapid day-night cycle, it’s rough for a species like ours that is adapted to a day over twice as long. It’s much easier for humans to adjust to longer days than shorter ones: it’s one thing to stay awake longer (good old caffeinated infusion works wonders for this) and then sleep in later; it’s another matter to make yourself fall asleep when you’re not tired yet. Most residents only sleep every two or three nights.

2) It’s hot.

Not intolerably hot, just…above normal human comfort levels. The planetary average temperature here is stated as 39°C, 20 degrees hotter than Old Earth, but that’s oversimplifying things. The planet doesn’t have much variation in climate across its surface. The rapid rotation and the voluminous atmosphere—lower in pressure overall, but with a larger planet there’s a lot more of it by mass—effectively distributes heat all around the planet. With no half-year-long polar nights to form ice caps that would reflect sunlight and create frigid arctic zones, Verdant’s poles remain pleasantly warm, basked in an eternal twilight with the orange sun perpetually straddling the horizon.

Temperatures average around 35-45°C across most of the planet, with relative humidity over 50% at all times. Due to the short days, the daily temperature range is small, typically no more than ±6°C. The polar regions stay around 30°C, while low-lying areas near the equator occasionally top 50°C. Although standard issue work uniforms contain built-in cooling systems, one must always take precautions against heat stress. Drink lots of water if you have to work outside air-conditioned areas, and take hourly breaks to go inside and cool off. Be aware of the symptoms of heat exhaustion and heat stroke, and report to your base’s medical facility at the first sign of them.

The heat doesn’t bother the native lifeforms; they thrive in it. What we consider comfortable room temperatures (20-22°C) gives the native fauna hypothermia, and slowly kills most local flora.

3) It’s wet.

Verdant is a damp planet, with rainfall a daily occurrence. The air is humid everywhere, contributing to the high average temperature, as water vapor is by far the most potent greenhouse gas. The dense vegetation all over the planet transpires huge amounts of water vapor back into the atmosphere, as part of the process that transports nutrients from the soil into the stems and leaves, and on such a wet planet, plants have no reason to do it in a way that uses water economically. In fact, plant transpiration is the primary driver of the planet’s water cycle.

Without a wide temperature differential to drive large-scale storm systems, the weather is nearly the same every day. In the mornings, the temperature and humidity are relatively comfortable and the skies are clear. This is when you want to go get all the outdoor work done that requires human hands to get it finished. As tepid morning turns to torrid afternoon, both temperature and humidity rise and cumulus clouds start filling the sky. By evening, massive thunderstorms rain down the day’s moisture again in a downpour that typically ends a bit after nightfall, bringing slightly cooler and drier air in their wake for the next morning’s brief respite from the oppressive heat.

Water is all too easy to come by here; the problem is in keeping it where you want it instead of having it go somewhere else. Keep stored water covered and out of direct sunlight or it will rapidly evaporate. Flooding is rarely an issue despite the high precipitation as soils generally have a high water capacity and plants quickly soak it all up.

4) You’re going to feel great on your first week or two here, but don’t get used to it.

There are two reasons why. The gravity here is only 73% of the standard 1 G you experience at every station and habitat. Verdant is fairly low in density, lacking significant amounts of heavy metals—something we’ll talk about more later—and with the planet being bigger, you’re further away from more of it. The second reason is that the air here is 35% oxygen by volume—not just due to the plants, but they play a key part—a much richer oxygen concentration than what standard life support systems provide. All the extra oxygen and the low gravity will put a spring in your step, but once you get used to it, you’re going to have a hard time getting used to standard environments again when you leave here.

Fires are a very serious problem here on Verdant due to the high atmospheric oxygen content. Flammable materials are used sparingly. Industrial equipment has to be carefully designed to avoid parts scraping together and electronics need extra insulation and surge protection, for the slightest spark can easily set off a runaway conflagration. While on a base, you’ll never be more than 20 meters from a fire extinguisher, and when you see what this air does to open flames, you’ll be thankful for that.

5) The planet is full of life, and it is irrepressible.

Biologists could spend millennia here trying to catalog everything that lives on Verdant. Agricultural workers will unfortunately spend much of their time pushing back against the ever-encroaching native flora. Local analogs of mold grow anywhere water sits stagnant for too long. Paved areas need to be carefully maintained and cracks quickly patched with construction granulate to keep seeds from getting into them, germinating, and buckling the surface. Many local plant species can grow 20 centimeters (or more!) per day. There are many tales of ships that have taken off from Verdant for the long trip to Moria Station and back, only to find trees growing from their vine-covered landing pad upon their return. Abandoned infrastructure is quickly reclaimed by the relentless greenery.

As for the native wildlife, there have fortunately been no reports of unprovoked attacks on humans. Larger creatures generally show no fear of humans and will ignore you if you leave them alone, but most can and usually will violently defend themselves. As a general rule, don’t antagonize the wildlife; most employee health insurance plans don’t cover getting maimed by wild animals because you thought it would be amusing to go pester one. Live and let live is the law of this jungle.

The small critters, though? While they’ll flee from you at first sight, they’ll get into anything unattended if they smell something edible inside. Food and produce not kept in tightly sealed containers will quickly be stolen and eaten by opportunistic scavengers and vermin analogs. Don’t leave storage containers open. Good solid walls and fences are a must to keep large herbivores off your base, as they will not hesitate to enter human settlements to eat your crops.

Fortunately, as humans aren’t native to Verdant, this means that the diseases endemic to its native wildlife don’t affect humans due to incompatible biology. Let’s hope this remains so.

Many of the native plant species are poisonous to humans. Never eat anything you find out in the wild without your local food experts first testing it for human biocompatibility and toxicology. The juicy-looking purple fruits of the Coleus cerifera (you’ll know one when you see it) may entice you to take a bite, but a mouthful of organofluorines will kill your appetite in a hurry…and it might just plain kill you if you don’t spit it out quick. When in doubt, you’re best off sticking to basic rations. That being said, there are a number of local delicacies that have been found to be both safe and tasty, so you can expect at least a little flavor in your daily meals.

Verdant is a planet of incredible biodiversity and no two bases are alike. Much of the planet remains unexplored beyond orbital scans, and local environments vary wildly. Always check what health and safety guidelines, and advisories on local hazards, are in effect on your base…then follow them. They’re there for good reason.

6) Nothing lasts forever.

For such a vibrant, living planet, it may come as a surprise to you that Verdant is actually a dying world. Dying slowly, but surely.

Wait, what? Dying? Don’t worry, it’s not going to happen in our lifetimes, not like poor old Earth, glassed in its prime by a rogue interstellar minor planet. Either we had the worst luck in the universe, or someone out there didn’t like the idea of another living planet that wasn’t theirs and sent that planet-killer our way long, long ago—but that’s another story…

No. It is doomed because of the very star that gives it life.

Verdant’s sun, a K-type orange dwarf, is expected to stay on the main sequence for a good thirty billion years, but it is already ten billion years old, a Population II star. Life was crawling out of Verdant’s seas when Earth’s solar system was still just a cloud of space dust. In the natural process of stellar evolution, all main sequence stars slowly grow hotter and brighter as they age. As the star warms, its habitable zone slowly creeps outward, a few millimeters per year—but over the aeons, that adds up to a lot. Any planet fortunate enough to be hospitable to life at the beginning of a star’s time on the main sequence will no longer be habitable by the end of it.

The planet’s crust has no metals in economically viable concentrations simply because metal didn’t exist in large quantities yet when the planet was born, hence the low density and gravity. Metals are forged from lighter elements in the hearts of massive stars, which seed them back to the universe again when they die. The dearth of minerals in general is the primary reason why agriculture is the only large industry on Verdant.

The steadily warming star’s habitable zone is now pushing out beyond Verdant’s orbit. The planet is entering a moist greenhouse state, with its water beginning to be lost to space. The hot steamy air is so saturated with water vapor that some of the vapor manages to reach the stratosphere, above the ozone layer. As water reaches the upper stratosphere, it gets broken down by ultraviolet light into hydrogen and oxygen. The hydrogen escapes into space. The oxygen falls back to the planet, contributing to the rich oxygen atmosphere.

When the water is gone, the life goes with it. But the natural death of a living planet is agonizingly and imperceptively slow to us ephemeral organic beings. We have tens of millions of years left to enjoy this wondrous jungle planet while it lasts.

Maybe that’ll even be enough time for us to save it.