The study of life in the universe is best described by which term?

• A. Biology
• B. Cosmology
• C. Exobiology
• D. Astrobiology

Answer: (D)

Naming the field that studies life across the cosmos helps separate what we’re studying from related disciplines. Biology focuses on life on Earth, cosmology looks at the origin and evolution of the universe itself, and exobiology is an older, narrower term for studying life beyond Earth. Astrobiology, on the other hand, is the interdisciplinary study of life in the universe—its origins, how widespread it might be, the environments that could support it, and how we detect it. This breadth lets astrobiology cover everything from habitability of planets and moons to potential biosignatures and future exploration, making it the best fit for “the study of life in the universe.” Exobiology is related but narrower in emphasis, while cosmology is not centered on life at all.