Spore in Space

283 Days

You are moss on the hull of a spacecraft. Endure the open void, then germinate.

How to play

ProtonemaGrowing filaments. Regrows biomass and heals, but only while nothing is actively striking you. No defense. Your calm-weather form.

Brood cellA tough pod that halves all damage. Cheap shelter for a single mild hazard. It only endures; it can't heal.

SporeSealed in its sporangium. Blocks nearly all damage, even stacked storms. But it's dormant: no growth, and viability slowly ebbs.

Shelter from the incoming hazard: brood for one mild threat, spore when storms stack or bite hard.

Snap back to protonema the instant it is calm, to heal and grow.

Or parry: tap Space (or the moss) right as a hazard strikes to deflect it for free and build your streak.

Every shelter spends biomass, and your final biomass is your germination score, so do not hide longer than you must.

Keys: 1 / 2 / 3 forms · Space parry · P pause · M mute

Storm front

The UV Season

Days 57 – 85

Checkpoint: adapt

Natural selection: keep one real survival adaptation for the rest of the voyage. Each is a trait that mosses and other extremophiles use to endure stress. Click or press 1 / 2 / 3.

Paused

Press P to resume.

Settings

Collection

Every form and hazard you have met on the voyage. Sealed entries reveal themselves the first time you encounter them.

The Science Behind the Game

Spore in Space dramatizes a real 2025 study. Here is how each part of the game maps to the research.

The organism (plant biology)

Physcomitrium patens is a model moss. Its life stages differ in toughness: growing protonema is fragile, a brood cell is hardier, and the dormant spore, sealed in its sporangium, is the most stress-tolerant. The adaptations you draft are real moss survival tools: flavonoid sunscreens, dehydrins, DNA-repair enzymes, heat-shock proteins, and a reinforced sporangium.

Research question

Can this moss survive prolonged, direct exposure to open space, and still germinate afterward?

Hypothesis

The dormant, encased spore is the most stress-tolerant stage, so it could survive conditions that kill growing tissue.

Methods

Researchers mounted moss sporophytes on the outside of the International Space Station for 283 days in 2022, across groups that differed in UV exposure, then brought them home, rehydrated the spores, and measured germination. In the game, the 283-day voyage is that exposure, and the five hazards (UV flare, UV storm, cosmic radiation, heat, cold) are the stressors tested.

Results, and why it is exciting

Of the fully UV-exposed spores, 86% still germinated (95 to 97% of the shielded groups). No land plant had ever survived so long exposed to open space. Your germination score at the end is this same measure.

Future directions

A model projected the encased spores could survive up to 5,600 days, about 15 years (the game's unlockable Projected Voyage). This feeds a bigger question, panspermia: if shielded spores can endure interplanetary transit, life might spread between worlds, and plants might one day be grown on the Moon or Mars.

Sources

Maeng, C.-h., et al. (2025). Extreme environmental tolerance and space survivability of the moss, Physcomitrium patens. iScience, 28(12), 113827.

Bennett, J. (2025). Moss spores survived in space for 9 months. Science News.

Moss survived 283 days in space, shocking biologists. (2025). Popular Science.

Moissl-Eichinger, C., Cockell, C., and Rettberg, P. (2016). Venturing into new realms? Microorganisms in space. FEMS Microbiology Reviews, 40(5), 722 to 737.

In a laboratory drawer, a colony of moss, older than roots, older than seeds. They wanted to know what it could survive.

They dried it, froze it to −196°, burned it with ultraviolet. Every stress that kills a plant. It folded inward, and held.

So they sent it higher than any green thing had ever gone.

Bolted to the outside of the hull, facing the open void. Two hundred and eighty-three days. Then, if anything was left, germinate.

click / Enter to continue

Two hundred and eighty-three days, and the moss came home alive. The lab cheered. Somebody brought cake.

Then someone re-checked the survival curve. It did not politely stop at 283 days. It kept climbing, right off the top of the page.

Extrapolated: five thousand six hundred days. Roughly fifteen years. "Oh," said the scientist, very quietly. "We may have stopped a little early."

So. Back outside you go, little moss. Mind the vacuum. See you in fifteen years or so.

click / Enter to continue

Mission ended

Vital signs across the voyage

Run stats

Leaderboard

#	Voyage	Days	Germ.	Score