Astrobiology

Astrobiology

Astrobiology is the study of the origin, evolution, distribution, and future of life in the universe extraterrestrial life and life on Earth. This interdisciplinary field encompasses the search for habitable environments in our Solar System and habitable planets outside our Solar System, the search for evidence of prebiotic chemistry, laboratory and field research into the origins and early evolution of life on Earth, and studies of the potential for life to adapt to challenges on Earth and in outer space.[2] Astrobiology addresses the question of whether life exists beyond Earth, and how humans can detect it if it does.[3] (The term exobiology is similar but more specific it covers the search for life beyond Earth, and the effects of extraterrestrial environments on living things.)[4] Astrobiology makes use of physics, chemistry, astronomy, biology, molecular biology, ecology, planetary science, geography, and geology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from the biosphere on Earth.[5][6] Astrobiology concerns itself with interpretation of existing scientific data; given more detailed and reliable data from other parts of the universe, the roots of astrobiology itselfphysics, chemistry and biologymay have their theoretical bases challenged. Although speculation is entertained to give context, astrobiology concerns

tself primarily with hypotheses that fit firmly into existing scientific theories. Earth is the only place in the universe known to harbor life.[7][8] However, recent advances in planetary science have changed fundamental assumptions about the possibility of life in the universe, raising the estimates of habitable zones around other stars and the search for extraterrestrial microbial life.[9] The possibility of life on Mars, either currently or in the past, is an active area of research. Astrobiology is etymologically derived from the Greek ---, astron, "constellation, star"; --, bios, "life"; and ---?, -logia, study. The synonyms of astrobiology are diverse; however, the synonyms were structured in relation to the most important sciences implied in its development: astronomy and biology. A synonym is exobiology from the Greek -?, "external"; --, bios, "life"; and --?, -logia, study. Another term used in the past is xenobiology, ("biology of the foreigners") a word coined in 1954 by science fiction writer Robert Heinlein in his work The Star Beast.[11] The term xenobiology has come to be used in a more specialized sense, to mean "biology based on foreign chemistry", whether of extraterrestrial or terrestrial (possibly synthetic) origin. Since alternate chemistry analogs to some life-processes have been created in the laboratory, xenobiology can be said to be an extant subject.