Final answer:
The origin of life on Earth is explained through various hypotheses, one being abiogenesis, which theorizes the transition from non-living to living matter. Astrobiology extends this topic to the cosmic scale, using principles that support the possibility of life beyond Earth, while addressing the Fermi paradox related to alien life encounters.
Step-by-step explanation:
The origin of life on Earth is a subject of intense scientific study. Currently, several hypotheses with supporting scientific evidence exist. Among these, one prominent theory is abiogenesis, which proposes life started from non-living matter through chemical processes. The discovery of 3.95 billion-year-old sedimentary rocks suggests life on Earth began earlier than previously thought, potentially during the Hadean Eon.
Astrobiology, a field that explores life's existence in the universe, relies on the Copernican principle that implies if life can develop on Earth, the same can occur elsewhere in the cosmos. The Fermi paradox, on the other hand, questions why we have not yet encountered more advanced extraterrestrial life if it is common in the universe. Life on Earth, as we know it, is comprised of organic molecules such as complex hydrocarbons, which result from the combination of chemical elements formed in stars.