Exobiologists

Exobiologists study life beyond Earth. The field, commonly known as exobiology or astrobiology, examines the origin, evolution, distribution, and future of life in the universe. It draws on biology, chemistry, geology, and astronomy to understand where life could exist and how it could be detected.

Historically, the term exobiology was introduced in the 1960s by Joshua Lederberg; today astrobiology is the more widely used umbrella term, reflecting a broader scope that includes planetary habitability, life detection, and the search for intelligent civilizations.

Research focuses on several interlocking questions: what conditions are compatible with life, both on early Earth and on other worlds; how life could arise from nonliving chemistry (abiogenesis); what biosignatures might betray life in planetary atmospheres or surfaces; and how humans might detect technosignatures. Field work includes studying extremophiles in Earth's deserts, ice, and hydrothermal systems to model possible extraterrestrial life. Laboratory experiments explore prebiotic chemistry and metabolism under alien-like conditions. Observations of exoplanets, comets, meteorites, and solar system bodies, along with data from space missions, inform habitat assessments and biosignature interpretation.

Practitioners come from biology, chemistry, geology, physics, and engineering; notable figures include Joshua Lederberg, Carl Sagan, and Jill Tarter, among others, who helped popularize and advance the search for life beyond Earth. The field continues to influence methods in planetary science and encourages interdisciplinary collaboration in exploring humanity’s place in the cosmos.