Astrobiology
"Exobiology"fredirectsfhere.fNotftofbefconfusedfwithfBioastronauticsforfXenobiology.
MarsCuriosityRover-Drilling-Sol170++-2.jpg
Thisfarticlefisfonefoffafseriesfon:
LifefinfthefUniverse
Astrobiology
HabitabilityfinfthefSolarfSystem
HabitabilityfoffMercuryHabitabilityfoffVenusLifefonfEarthHabitabilityfoffMarsHabitabilityfoffEnceladusHabit
abilityfoffEuropaHabitabilityfoffTitan
LifefoutsidefthefSolarfSystem
CircumstellarfhabitablefzoneExoplanetologyPlanetaryfhabitabilitySETI
vte
Nucleicfacidsfmayfnotfbefthefonlyfbiomoleculesfinfthefuniversefcapablefoffcodingfforflifefprocesses.[1]
Astrobiology,falsofknownfasfexobiology,fisfanfinterdisciplinaryfscientificffieldfthatfstudiesftheforigins,fearlyfe
volution,fdistribution,fandffuturefofflifefinfthefuniverse.[2]fAstrobiologyfisfthefmultidisciplinaryffieldfthatfinv
estigatesfthefdeterministicfconditionsfandfcontingentfeventsfwithfwhichflifefarises,fdistributes,fandfevolvesf
infthefuniverse.[3]fItfconsidersfthefquestionfoffwhetherfextraterrestrialflifefexists,fandfiffitfdoes,fhowfhuman
sfcanfdetectfit.[4]
Astrobiologyfmakesfusefoffmolecularfbiology,fbiophysics,fbiochemistry,fchemistry,fastronomy,fphysicalfcos
mology,fexoplanetology,fgeology,fpaleontology,fandfichnologyftofinvestigatefthefpossibilityfofflifefonfotherf
worldsfandfhelpfrecognizefbiospheresfthatfmightfbefdifferentffromfthatfonfEarth.[5]fTheforiginfandfearlyfevo
lutionfofflifefisfanfinseparablefpartfoffthefdisciplinefoffastrobiology.[6]fAstrobiologyfconcernsfitselffwithfinter
pretationfoffexistingfscientificfdata,fandfalthoughfspeculationfisfentertainedftofgivefcontext,fastrobiologyfco
ncernsfitselffprimarilyfwithfhypothesesfthatffitffirmlyfintofexistingfscientificftheories.
Thisfinterdisciplinaryffieldfencompassesfresearchfonftheforiginfoffplanetaryfsystems,foriginsfofforganicfcom
poundsfinfspace,frock-water-
carbonfinteractions,fabiogenesisfonfEarth,fplanetaryfhabitability,fresearchfonfbiosignaturesfforflifefdetectio
n,fandfstudiesfonfthefpotentialfforflifeftofadaptftofchallengesfonfEarthfandfinfouterfspace.[7][8][9]
,BiochemistryfmayfhavefbegunfshortlyfafterfthefBigfBang,f13.8fbillionfyearsfago,fduringfafhabitablefepochfwh
enfthefUniversefwasfonlyf10–
17fmillionfyearsfold.[10][11]fAccordingftofthefpanspermiafhypothesis,fmicroscopicflife—
distributedfbyfmeteoroids,fasteroidsfandfotherfsmallfSolarfSystemfbodies—
mayfexistfthroughoutfthefuniverse.[12][13]fAccordingftofresearchfpublishedfinfAugustf2015,fveryflargefgala
xiesfmayfbefmoreffavorableftofthefcreationfandfdevelopmentfoffhabitablefplanetsfthanfsuchfsmallerfgalaxie
sfasfthefMilkyfWay.[14]fNonetheless,fEarthfisfthefonlyfplacefinfthefuniversefhumansfknowftofharborflife.[15][
16]fEstimatesfoffhabitablefzonesfaroundfotherfstars,[17][18]fsometimesfreferredftofasf"Goldilocksfzones",[
19][20]falongfwithfthefdiscoveryfoffthousandsfoffextrasolarfplanetsfandfnewfinsightsfintofextremefhabitatsf
herefonfEarth,fsuggestfthatftherefmayfbefmanyfmorefhabitablefplacesfinfthefuniversefthanfconsideredfpossi
blefuntilfveryfrecently.[21][22][23]
CurrentfstudiesfonfthefplanetfMarsfbyfthefCuriosityfandfPerseverancefroversfarefsearchingfforfevidencefoffa
ncientflifefasfwellfasfplainsfrelatedftofancientfriversforflakesfthatfmayfhavefbeenfhabitable.[24][25][26][27]fT
hefsearchfforfevidencefoffhabitability,ftaphonomyf(relatedftoffossils),fandforganicfmoleculesfonfthefplanetf
MarsfisfnowfafprimaryfNASAfandfESAfobjective.
Evenfiffextraterrestrialflifefisfneverfdiscovered,fthefinterdisciplinaryfnaturefoffastrobiology,fandfthefcosmicfa
ndfevolutionaryfperspectivesfengenderedfbyfit,fmayfstillfresultfinfafrangefoffbenefitsfherefonfEarth.[28][furt
herfexplanationfneeded]
Contents
1 Overview
2 Methodology
2.1 Planetaryfhabitability
2.2 Communicationfattempts
2.3 Elementsfoffastrobiology
2.3.1 Astronomy
2.3.2 Biology
2.3.3 Astroecology
2.3.4 Astrogeology
3 LifefinfthefSolarfSystem
4 RarefEarthfhypothesis
, 5 Research
5.1 Researchfoutcomes
5.2 Extremophiles
6 Missions
6.1 Proposedfconcepts
7 Seefalso
8 References
9 Bibliography
10 Furtherfreading
11 Externalflinks
Overview
TheftermfwasffirstfproposedfbyfthefRussianf(Soviet)fastronomerfGavriilfTikhovfinf1953.[29]fAstrobiologyfisfe
tymologicallyfderivedffromfthefGreekfἄστρον,fastron,f"constellation,fstar";fβίος,fbios,f"life";fandf-λογία,f-
logia,fstudy.fThefsynonymsfoffastrobiologyfarefdiverse;fhowever,fthefsynonymsfwerefstructuredfinfrelationft
ofthefmostfimportantfsciencesfimpliedfinfitsfdevelopment:fastronomyfandfbiology.fAfclosefsynonymfisfexobi
ologyffromfthefGreekfΈξω,f"external";fΒίος,fbios,f"life";fandfλογία,f-
logia,fstudy.fTheftermfexobiologyfwasfcoinedfbyfmolecularfbiologistfandfNobelfPrizefwinnerfJoshuafLederbe
rg.[30]fExobiologyfisfconsideredftofhavefafnarrowfscopeflimitedftofsearchfofflifefexternalftofEarth,fwhereasfs
ubjectfareafoffastrobiologyfisfwiderfandfinvestigatesftheflinkfbetweenflifefandfthefuniverse,fwhichfincludesft
hefsearchfforfextraterrestrialflife,fbutfalsofincludesfthefstudyfofflifefonfEarth,fitsforigin,fevolutionfandflimits.
ItfisfnotfknownfwhetherflifefelsewherefinfthefuniversefwouldfutilizefcellfstructuresflikefthoseffoundfonfEarth.
[31]f(Chloroplastsfwithinfplantfcellsfshownfhere.)
Anotherftermfusedfinfthefpastfisfxenobiology,f("biologyfoffthefforeigners")fafwordfusedfinf1954fbyfscienceffic
tionfwriterfRobertfHeinleinfinfhisfworkfThefStarfBeast.[32]fTheftermfxenobiologyfisfnowfusedfinfafmorefspeci
alizedfsense,ftofmeanf"biologyfbasedfonfforeignfchemistry",fwhetherfoffextraterrestrialforfterrestrialf(possi
blyfsynthetic)forigin.fSincefalternatefchemistryfanalogsftofsomeflife-
processesfhavefbeenfcreatedfinftheflaboratory,fxenobiologyfisfnowfconsideredfasfanfextantfsubject.[33]
Whilefitfisfanfemergingfandfdevelopingffield,fthefquestionfoffwhetherflifefexistsfelsewherefinfthefuniversefisf
afverifiablefhypothesisfandfthusfafvalidflinefoffscientificfinquiry.[34][35]fThoughfoncefconsideredfoutsidefth
efmainstreamfoffscientificfinquiry,fastrobiologyfhasfbecomefafformalizedffieldfoffstudy.fPlanetaryfscientistfD
avidfGrinspoonfcallsfastrobiologyfaffieldfoffnaturalfphilosophy,fgroundingfspeculationfonfthefunknown,finfk
"Exobiology"fredirectsfhere.fNotftofbefconfusedfwithfBioastronauticsforfXenobiology.
MarsCuriosityRover-Drilling-Sol170++-2.jpg
Thisfarticlefisfonefoffafseriesfon:
LifefinfthefUniverse
Astrobiology
HabitabilityfinfthefSolarfSystem
HabitabilityfoffMercuryHabitabilityfoffVenusLifefonfEarthHabitabilityfoffMarsHabitabilityfoffEnceladusHabit
abilityfoffEuropaHabitabilityfoffTitan
LifefoutsidefthefSolarfSystem
CircumstellarfhabitablefzoneExoplanetologyPlanetaryfhabitabilitySETI
vte
Nucleicfacidsfmayfnotfbefthefonlyfbiomoleculesfinfthefuniversefcapablefoffcodingfforflifefprocesses.[1]
Astrobiology,falsofknownfasfexobiology,fisfanfinterdisciplinaryfscientificffieldfthatfstudiesftheforigins,fearlyfe
volution,fdistribution,fandffuturefofflifefinfthefuniverse.[2]fAstrobiologyfisfthefmultidisciplinaryffieldfthatfinv
estigatesfthefdeterministicfconditionsfandfcontingentfeventsfwithfwhichflifefarises,fdistributes,fandfevolvesf
infthefuniverse.[3]fItfconsidersfthefquestionfoffwhetherfextraterrestrialflifefexists,fandfiffitfdoes,fhowfhuman
sfcanfdetectfit.[4]
Astrobiologyfmakesfusefoffmolecularfbiology,fbiophysics,fbiochemistry,fchemistry,fastronomy,fphysicalfcos
mology,fexoplanetology,fgeology,fpaleontology,fandfichnologyftofinvestigatefthefpossibilityfofflifefonfotherf
worldsfandfhelpfrecognizefbiospheresfthatfmightfbefdifferentffromfthatfonfEarth.[5]fTheforiginfandfearlyfevo
lutionfofflifefisfanfinseparablefpartfoffthefdisciplinefoffastrobiology.[6]fAstrobiologyfconcernsfitselffwithfinter
pretationfoffexistingfscientificfdata,fandfalthoughfspeculationfisfentertainedftofgivefcontext,fastrobiologyfco
ncernsfitselffprimarilyfwithfhypothesesfthatffitffirmlyfintofexistingfscientificftheories.
Thisfinterdisciplinaryffieldfencompassesfresearchfonftheforiginfoffplanetaryfsystems,foriginsfofforganicfcom
poundsfinfspace,frock-water-
carbonfinteractions,fabiogenesisfonfEarth,fplanetaryfhabitability,fresearchfonfbiosignaturesfforflifefdetectio
n,fandfstudiesfonfthefpotentialfforflifeftofadaptftofchallengesfonfEarthfandfinfouterfspace.[7][8][9]
,BiochemistryfmayfhavefbegunfshortlyfafterfthefBigfBang,f13.8fbillionfyearsfago,fduringfafhabitablefepochfwh
enfthefUniversefwasfonlyf10–
17fmillionfyearsfold.[10][11]fAccordingftofthefpanspermiafhypothesis,fmicroscopicflife—
distributedfbyfmeteoroids,fasteroidsfandfotherfsmallfSolarfSystemfbodies—
mayfexistfthroughoutfthefuniverse.[12][13]fAccordingftofresearchfpublishedfinfAugustf2015,fveryflargefgala
xiesfmayfbefmoreffavorableftofthefcreationfandfdevelopmentfoffhabitablefplanetsfthanfsuchfsmallerfgalaxie
sfasfthefMilkyfWay.[14]fNonetheless,fEarthfisfthefonlyfplacefinfthefuniversefhumansfknowftofharborflife.[15][
16]fEstimatesfoffhabitablefzonesfaroundfotherfstars,[17][18]fsometimesfreferredftofasf"Goldilocksfzones",[
19][20]falongfwithfthefdiscoveryfoffthousandsfoffextrasolarfplanetsfandfnewfinsightsfintofextremefhabitatsf
herefonfEarth,fsuggestfthatftherefmayfbefmanyfmorefhabitablefplacesfinfthefuniversefthanfconsideredfpossi
blefuntilfveryfrecently.[21][22][23]
CurrentfstudiesfonfthefplanetfMarsfbyfthefCuriosityfandfPerseverancefroversfarefsearchingfforfevidencefoffa
ncientflifefasfwellfasfplainsfrelatedftofancientfriversforflakesfthatfmayfhavefbeenfhabitable.[24][25][26][27]fT
hefsearchfforfevidencefoffhabitability,ftaphonomyf(relatedftoffossils),fandforganicfmoleculesfonfthefplanetf
MarsfisfnowfafprimaryfNASAfandfESAfobjective.
Evenfiffextraterrestrialflifefisfneverfdiscovered,fthefinterdisciplinaryfnaturefoffastrobiology,fandfthefcosmicfa
ndfevolutionaryfperspectivesfengenderedfbyfit,fmayfstillfresultfinfafrangefoffbenefitsfherefonfEarth.[28][furt
herfexplanationfneeded]
Contents
1 Overview
2 Methodology
2.1 Planetaryfhabitability
2.2 Communicationfattempts
2.3 Elementsfoffastrobiology
2.3.1 Astronomy
2.3.2 Biology
2.3.3 Astroecology
2.3.4 Astrogeology
3 LifefinfthefSolarfSystem
4 RarefEarthfhypothesis
, 5 Research
5.1 Researchfoutcomes
5.2 Extremophiles
6 Missions
6.1 Proposedfconcepts
7 Seefalso
8 References
9 Bibliography
10 Furtherfreading
11 Externalflinks
Overview
TheftermfwasffirstfproposedfbyfthefRussianf(Soviet)fastronomerfGavriilfTikhovfinf1953.[29]fAstrobiologyfisfe
tymologicallyfderivedffromfthefGreekfἄστρον,fastron,f"constellation,fstar";fβίος,fbios,f"life";fandf-λογία,f-
logia,fstudy.fThefsynonymsfoffastrobiologyfarefdiverse;fhowever,fthefsynonymsfwerefstructuredfinfrelationft
ofthefmostfimportantfsciencesfimpliedfinfitsfdevelopment:fastronomyfandfbiology.fAfclosefsynonymfisfexobi
ologyffromfthefGreekfΈξω,f"external";fΒίος,fbios,f"life";fandfλογία,f-
logia,fstudy.fTheftermfexobiologyfwasfcoinedfbyfmolecularfbiologistfandfNobelfPrizefwinnerfJoshuafLederbe
rg.[30]fExobiologyfisfconsideredftofhavefafnarrowfscopeflimitedftofsearchfofflifefexternalftofEarth,fwhereasfs
ubjectfareafoffastrobiologyfisfwiderfandfinvestigatesftheflinkfbetweenflifefandfthefuniverse,fwhichfincludesft
hefsearchfforfextraterrestrialflife,fbutfalsofincludesfthefstudyfofflifefonfEarth,fitsforigin,fevolutionfandflimits.
ItfisfnotfknownfwhetherflifefelsewherefinfthefuniversefwouldfutilizefcellfstructuresflikefthoseffoundfonfEarth.
[31]f(Chloroplastsfwithinfplantfcellsfshownfhere.)
Anotherftermfusedfinfthefpastfisfxenobiology,f("biologyfoffthefforeigners")fafwordfusedfinf1954fbyfscienceffic
tionfwriterfRobertfHeinleinfinfhisfworkfThefStarfBeast.[32]fTheftermfxenobiologyfisfnowfusedfinfafmorefspeci
alizedfsense,ftofmeanf"biologyfbasedfonfforeignfchemistry",fwhetherfoffextraterrestrialforfterrestrialf(possi
blyfsynthetic)forigin.fSincefalternatefchemistryfanalogsftofsomeflife-
processesfhavefbeenfcreatedfinftheflaboratory,fxenobiologyfisfnowfconsideredfasfanfextantfsubject.[33]
Whilefitfisfanfemergingfandfdevelopingffield,fthefquestionfoffwhetherflifefexistsfelsewherefinfthefuniversefisf
afverifiablefhypothesisfandfthusfafvalidflinefoffscientificfinquiry.[34][35]fThoughfoncefconsideredfoutsidefth
efmainstreamfoffscientificfinquiry,fastrobiologyfhasfbecomefafformalizedffieldfoffstudy.fPlanetaryfscientistfD
avidfGrinspoonfcallsfastrobiologyfaffieldfoffnaturalfphilosophy,fgroundingfspeculationfonfthefunknown,finfk
