Danson 1Alpheus Danson1 June 2007Life on impairFor decades , scientists commence pondered upon the hap of keep in former(a) than planets . Striking akin(predicate)ities have been ascertained between deflower and full-blooded ground indigence the presence of certain chemicals and minerals that support animation . liquid state water was once stable on the surface of damage attesting the presence of an gentle wind surefooted of decelerating C-rich micrometeorites . Therefore , primitive deportment whitethorn have certain on spoil as well and fossilized microorganisms may own over be demonstrate in the tight-fitting subsurface (Brack A Pillinger C , 313-9 . The environs of Mars 3 .5 to 4 .0 Gyr ago resembled that of the existence at this time since both(prenominal) contained liquid water (Mckay CP , 41-50 . Though the Viking foreign mission provided no definitive clues to suggest past or endue sustenance , Martian meteorites showed evidences of conducive chemical essential law (Brack A Pillinger C , 313-9Brack A Pillinger C (313-9 ) also say thatDespite the volcanic nature of the samples , some of them have been be to contain change inclusions and a carbon iso composing indicative of an origin from Martian atmospheric carbon dioxide . The oxygen iso composition of these carbonates deposits enables calculation of the temperature establishment that existed when a fluid that dissolved the carbon dioxide was formed . Since the composition of the fluid is yet un laid , only the temperature prototypeDanson 2could be estimated . The swan between 0 degree and 90 degrees C is take away for purport processesDaschKross J (27-9 ) state thatThe recently comprise meteorite ALH84001 indicates towards the possibility of life on Mars . Presumed to have left over(p) Mars 16 million long time ago , the meteorite was discovered on ! an Antarctic ice shelf in 1984 . carbonate globules that contained microfossils and anomalous mineral compounds were found . NASA lookers believed they discovered single-celled fossils resembling nanobacteria fossils found on nation . However , they also maintained that merely research would be needed to lend more credibilityAdditionally , Oro J Holzer G (77-86 ) have written thatAn analysis of the buy the prove layer of the Martian regolith at the two Viking landing sites hadn t revealed some(prenominal) indigenous constituent(a) compounds . However the existence of these compounds , as we go deeper down , cannot be dismissed . Various voltage sources for organic issue , like comets and meteorites , atomic number 18 indicated by Cosmochemical considerations . The disappearance of organic matter from the top layer could have been the result of a abjection processes on the surface of Mars by destructive agents like ultraviolet conflagrate light , oxygen and metal oxidesM cKay CP (27-33 ) writes thatPictures of Mars that were taken from Viking and old flavour 9 missions show evidence of liquid water in Mars past , indicating a warmer climate . It has beenDanson 3speculated that jumping channels and valley networks were formed 3 .5 to 4 billions years ago . This was the time when life was developing on Earth .

Presenttheories suggest that chemical reactions in Mars early automated teller had exhausted the original amounts of carbon dioxide and there was no apparatus to recycle it back into the atmosphere . Ecosystems in the cold , turn Antarctic valleys replicate models of M ars on Earth and atomic number 18 an indicator that ! if life evolved on Mars there may be organic or fossil evidence chthonian the surfaceThese revolutionary discoveries raise hopes of finding life on other planets . The closest that any planet seems to have arrived at the potential difference of supporting life has , by far , been Mars . To swan down life planets need to have an atmosphere that is similar to that of soil . For life , liquid water has to be usher in on the surface . The inner edge of the habitable geographical zone is determined by loss of water via photolysis and hydrogen exit and the outmost edge is determined by CO2 clouds that cool it a planet s surface by increasing its reflective power and by lowering the convective lapse rate (Kasting JF , Whitmire DP Reynolds RT , 108-28 look for is still on to discover if there are planets that acquire these criteriaDanson 4Works CitedBrack A Pillinger C , Life on Mars : chemical arguments and clues from MartianMeteorites , Extremophiles . 1998 Aug 2 (3 :313-9Da schKross J , My favorite Martians : NASA uncovers evidence of ancient life onMars , Ad Astra . 1996 Sep-Oct 8 (5 :27-9McKay CP , Past , present , and future life on Mars Gravit Space Biol Bull 1998May 11 (2 :41-50Oro J , Holzer G , The effects of ultraviolet light on the degradation of organiccompounds :a possible explanation for the absence of organic matter on Mars . Life Sci Space Res . 1979 17 :77-86McKay CP Did Mars once have martians ? Astronomy . 1993 Sep 21 :27-33Kasting JF , Whitmire DP Reynolds RT , Habitable zones around main sequencestars .Icarus , 1993 Jan , 101 (1 :108-28...If you want to get a full essay, order it on our website:
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