Earth, Life, Space

Abstract This chapter discusses how the scientific search for evidence of extraterrestrial life has affected people's conception of the terrestrial biosphere. Austrian geologist Eduard Suess originated the term “biosphere” in 1875, describing Earth's biosphere as the area of the planet that supports life. With a deeper understanding of the history and nature of the terrestrial biosphere, the community of scientists engaged in space science and exploration recognizes the possibility of other biospheres beyond Earth. As a result, the quest to find evidence of extraterrestrial life has affected people's conception of the biosphere, the way they think about their home planet and their place on it, and their perspective on the possibility of extraterrestrial biospheres nearby and far away. Indeed, astrobiology, planetary exploration, and exoplanet science have made significant contributions to this changing understanding.