Biosignatures are crucial indicators in the search for extraterrestrial life, representing any substance or phenomenon providing scientific evidence of past or...
Biosignatures are any evidence of past or present life, detectable by scientific means. This can include organic molecules, cellular structures, metabolic byproducts, or characteristic atmospheric gas compositions.
They are the primary targets in astrobiology's quest for extraterrestrial life. Identifying reliable biosignatures allows scientists to assess the potential habitability of planets and moons, and to detect actual signs of life beyond Earth.
Examples include specific atmospheric gas combinations (like oxygen and methane in disequilibrium), complex organic molecules, fossilized microorganisms, isotopic fractionation patterns, and characteristic spectral absorption lines from exoplanet atmospheres.
Scientists use powerful telescopes to analyze exoplanet atmospheres for unique chemical compositions, send probes to collect samples from Mars or icy moons, and study ancient Earth rocks to understand how biosignatures form and persist.