Produced by: Tarun Mishra
Scientists are questioning whether alien life needs a planet to exist. Traditionally, planetary surfaces have been seen as ideal environments, like Earth, with its stable gravity, protective atmosphere, and resources.
Earth's conditions — gravitational stability, atmospheric shielding, and an abundance of vital elements — guide our search for extraterrestrial life, shaping the assumption that similar conditions are necessary elsewhere.
A recent preprint, accepted for publication in Astrobiology, proposes that life could thrive outside planets. The study investigates whether organisms might survive in space by constructing self-sustaining environments without relying on a planetary surface.
Astronauts on the International Space Station show that life can exist in space, though they require Earth-supplied resources. Simpler organisms, like tardigrades, which can endure the vacuum of space, hint at life’s resilience in extreme conditions.
Organisms in space would face key challenges: maintaining pressure in a vacuum, retaining heat for liquid water, and conserving essential elements. The study suggests a biological membrane could serve as a “shell” to keep internal pressure stable, similar to the depth of 10 meters underwater.
Just as the Saharan silver ant controls body temperature through selective light absorption, a free-floating colony of organisms would need a membrane to absorb or reflect light to maintain temperature, simulating a greenhouse effect without an atmosphere.
Unlike planets that use gravity to retain elements, an organic colony would lose lightweight elements over time. To survive, the colony would need to find resources in nearby asteroids or develop a closed-loop recycling system to maintain vital elements.
This research could impact human space exploration, suggesting future habitats could use bioengineered materials for sustainable ecosystems. Self-sustaining biohabitats could reduce dependence on Earth-based supplies, opening new possibilities for space habitats.