Stellum and Planetum

Habitat Nine, known colloquially as “Hab-9,” was a test platform for colonization. Agé, the largest moon around the gas giant Xevioso, second planet in the Kal system, teemed with life; slender plants that grew tall in the light gravity, a healthy micro-biome, and small creatures similar to nematodes on Earth.

Although Agé orbited Xevioso once every nineteen hours, it was almost tidally locked to the gas giant. The moon completed one rotation relative to its parent in a period of 413 Earth days, while the Xevioso system orbited its star every 204 Earth days.

“We should get the last of the crops in,” Tara said. “We’re nearly halfway to facing planet-side.”

The rising Xevioso filled the sky with its splendor. Swirls and bands of color adorned the gas giant; browns, oranges, and yellows, along with a deep purple band that marked its equator.

Lev looked at the planet looming in the sky. “It won’t be as bright, but at least it won’t be four hundred days of darkness. The way Xev reflects, the only dark times will be when we’re on the backside of the planet; same as now.”

“We have some low-light crops to test out during the planet-side transition.” Tara pulled her light jacket tighter around her shoulders. “The wind is picking up. When was the last time the ventgrass was checked?”

“It’s been a few days. We should do that before it seeds again.”

The native plants of Agé were compatible with humans and their crops, apart from a highly toxic, stiff, grass-like plant found only around the steam vents that dotted the landscape. The “ventgrass” contained high levels of a novel alkaloid and spread its tiny seeds on the slightest breeze. When dropped too far from a steam vent, the seeds didn’t germinate, instead decaying and poisoning the ground on which they landed, dotting the ground with centimeter-sized dead spots.

“Let’s start with that, then.” Tara shrugged into her hazard suit, checking that her mask made a good seal, and her filters were fresh. She was glad to get into the suit, adding another layer of protection against the chilling fingers of the wind.

As they neared the steam vent, their worst fears were confirmed. “It’s gone to seed already,” Lev said.

“That’s way too fast.” She turned on her radio to the habitat. “Tara to Hab-9. Close and seal all doors, use only air locks, do not leave without protective gear. Ventgrass is seeding. Run the air purifiers on full power, wipe down all surfaces. Any symptoms of alkaloid poisoning are to be treated as an immediate emergency.”

The responses back from the habitat were quick and clipped. Everyone there knew their job and the dangers it entailed. Countless drills had prepared them for a situation like this.

Tara placed a plastic bag over one of the clumps of ventgrass and dug it out at the roots.

“They must be seasonally reactive.” Lev burned the remainder of the ventgrass with a small torch. “With this wind, the entire crop is ruined.”

“Yeah, there’s no telling how much seed has settled on the vegetables, and we can’t dig the tubers without contaminating them.”

“They’re all seed crop now, if they survive.”

They returned to the habitat in silence. After moving through the decontaminating airlock, they shed their hazard suits. The wind increased through the following hours and days, the chill it carried turning into biting cold.

Over the following days, Tara and Lev returned to the vent. The ventgrass doubled, then trebled its rate of growth as the winds grew icier. The steam from the vent turned to fine snow in the wind, carrying the seeds farther than they could travel on their own.

A layer of ice formed as the snow fell and was constantly groomed by the undying winds. The temperature dropped well below freezing, the sky taken up by the swirls of the gas giant overhead. When Xevioso stood between Agé and the sun, the planet’s edge was limned in light surrounding the inscrutable dark of its surface, with bright stars in the small bits of sky not taken up by its looming presence.

By the end of the second week, the winds had receded, returning to the gentle breezes they were accustomed to. The ground had gone hard and frozen at the surface, under a layer of ice onto which a growing powder of constant snow fell.

“We have two hundred days of this?” Lev asked.

“It looks that way.” Tara studied the soil from the roots of the ventgrass she had brought into the lab. The nematode-like creatures were unaffected by the toxins. One of the micro-organisms they fed on seemed to thrive on those same alkaloids, converting them to non-toxic hydrocarbons.

“So much for the low-light crops. We can’t plant, even if the ground wasn’t frozen,” Lev sighed. “I’m not even sure we’ll get a full season of growing, since we have to clean everything up after all the seeding.”

“We don’t have to,” Tara said. “That’s up to these guys.” She held a Petri dish grown grey with the bacteria-like organisms in question.

Lev gave her a doubtful glance. “How long will that take? When we landed it was already a hundred days into the sun-side cycle.”

“And it was lush. I have a feeling this will happen faster than either of us expect. Just like the sudden change in temperature.”

“So, what’s the plan?”

“We grow a bunch of this and spread it as soon as we can. It slows down at sub-freezing temperatures but doesn’t die.”

“So, the grey slime eats the alkaloid, and the nemagétodes eat the bacteria, right? A combined nitrogen-fixer. Maybe alkateria and nitrotodes….”

“Those names are terrible.” Tara didn’t feel like going over yet again how Lev’s acceptable name for the ventgrass was not license to name everything else, so she gave it a rest. “That’s it, essentially. After the pseudo-bacteria break down the alkaloids, the pseudo-nematodes eat them and release nitrogen in the soil.”

“And you’re pretty certain it happens fast?”

“Yep. How long do the dead spots last?” Tara asked.

“Usually a few weeks.”

“Not the ones in our crops. We amended the soil, and these guys are still trying to repopulate. I meant in the native plants.”

“Well,” Lev said, “you get some permanent black spots on the leaves, but the ground cover usually fills back in within a couple days.”

“Exactly. Now, since we have a couple hundred days of cold, why don’t we get to work building new soil amendments with these guys?”

“By the way,” Lev asked, “what are we calling the seasons? I was thinking stellum and planetum. Just need to figure out when stellumnar and planetumnar solstices are.”

“Um, Lev, what’s wrong with summer and winter?” Tara asked.

Lev shrugged. “Boring.”