Research Finds Plate Tectonics Limit Technological Alien Life Milky Way

Recent research highlights the rarity and complexity of life-supporting planets like Earth in the Milky Way. The proto-Earth initially lacked essential life ingredients such as water and carbon compounds until a later planetary collision, possibly with Theia, delivered these vital elements, making life possible. Studies of exoplanets like Trappist-1e suggest the potential for Earth-like atmospheres, raising hopes for extraterrestrial life, while Mars exploration provides tantalizing but inconclusive evidence of ancient microbial life. However, new findings indicate that Earth-like worlds with the right balance of nitrogen, oxygen, and carbon dioxide, combined with plate tectonics to regulate atmospheric carbon, are exceedingly rare. The presence of plate tectonics is critical for sustaining life by maintaining the carbon-silicate cycle, but even Earth’s biosphere faces limits, potentially ending in a few hundred million to a billion years due to atmospheric changes. These insights underscore both the uniqueness of Earth's habitability and the challenges in finding technologically advanced extraterrestrial civilizations, which may be tens of thousands of light-years away and extremely old if they exist contemporaneously with us.