Interplanetary frontiers: terraforming from an invasion science perspective

The pursuit of a multi‐planetary existence represents one of humanity's greatest frontiers. If applied justly, it offers an opportunity to extend its civilization's lifespan amid escalating sustainability crises on Earth. One approach increasingly gaining traction is terraforming, a hitherto theoretical ecological and evolutionary experiment revolving around introducing terrestrial species to extraterrestrial planets to make these habitable to life forms from Earth. This discussion therefore sits alongside broader debates on the Anthropocene, in which human technological agency increasingly operates on ever‐expanding planetary scales, thus raising important questions about humanity's ecological responsibility beyond planet Earth. While possibly holding an untapped potential to contribute to safeguarding humanity amid escalating sustainability crises, introducing Earth species to extraterrestrial ecosystems carries profound ecological risks as well as moral and ethical concerns. Insights from conceptually similar established scientific fields can guide grounded and well‐governed strategies. Here, we revisit the concept of terraforming through the lens of invasion science to identify ecologically responsible pathways for navigating the double‐edged sword of an (so far) impossible large‐scale human expansion into interplanetary atmospheres.