Editing Miller–Urey experiment (section)

=== Contemporary experiments ===
[[File:Huygens_surface_color_enhanced.jpg|thumb|324x324px|The surface of [[Titan (moon)|Titan]] as viewed from the [[Huygens (spacecraft)|''Huygens'' lander]]. [[Tholin]]s, complex particles formed by UV irradiation on the N<sub>2</sub> and CH<sub>4</sub> atmosphere, are likely the source of the reddish haze.]]
There were a few similar spark discharge experiments contemporaneous with Miller-Urey. An article in ''[[The New York Times]]'' (March 8, 1953) titled "Looking Back Two Billion Years" describes the work of Wollman M. MacNevin at [[Ohio State University]], before the Miller Science paper was published in May 1953. MacNevin was passing 100,000V sparks through methane and water vapor and produced "[[resin]]ous solids" that were "too complex for analysis."<ref name="Lazcano-2003" /><ref>{{cite book |author=Krehl, Peter O. K. |title=History of Shock Waves, Explosions and Impact: A Chronological and Biographical Reference |publisher=[[Springer-Verlag]] |year=2009 |pages=603}}</ref><ref>{{Cite news |title=Looking Back Two Billion Years |language=en |work=The New York Times |url=http://timesmachine.nytimes.comhttp//timesmachine.content-tagging.us-east-1-01.prd.dvsp.nyt.net/timesmachine/1953/03/08/92690093.html?pageNumber=159 |access-date=2023-11-14}}</ref> Furthermore, K. A. Wilde submitted a manuscript to ''Science'' on December 15, 1952, before Miller submitted his paper to the same journal in February 1953. Wilde's work, published on July 10, 1953, used voltages up to only 600V on a binary mixture of [[carbon dioxide]] (CO<sub>2</sub>) and water in a flow system and did not note any significant reduction products.<ref>{{cite journal |last1=Wilde |first1=Kenneth A. |last2=Zwolinski |first2=Bruno J. |last3=Parlin |first3=Ransom B. |date=July 1953 |title=The Reaction Occurring in CO<sub>2</sub>, <sub>2</sub>O Mixtures in a High-Frequency Electric Arc |journal=[[Science (journal)|Science]] |volume=118 |issue=3054 |pages=43–44 |bibcode=1953Sci...118...43W |doi=10.1126/science.118.3054.43-a |pmid=13076175 |s2cid=11170339}}</ref> According to some, the reports of these experiments explain why Urey was rushing Miller's manuscript through ''Science'' and threatening to submit to the ''Journal of the American Chemical Society.''<ref name="Lazcano-2003" />

By introducing an experimental framework to test prebiotic chemistry, the Miller–Urey experiment paved the way for future origin of life research.<ref>{{Cite book |last=James Cleaves II |first=H. |title=Prebiotic Chemistry and Life's Origin |chapter=The Miller–Urey Experiment's Impact on Modern Approaches to Prebiotic Chemistry |date=2022 |chapter-url=https://books.rsc.org/books/edited-volume/2003/chapter/4583571/The-Miller-Urey-Experiment-s-Impact-on-Modern |pages=165–176 |language=en |doi=10.1039/9781839164798-00165|isbn=978-1-78801-749-7 }}</ref> In 1961, [[Joan Oró]] produced milligrams of the [[nucleobase]] [[adenine]] from a concentrated solution of HCN and NH<sub>3</sub> in water.<ref>{{cite journal |vauthors=Oró J, Kimball AP |date=August 1961 |title=Synthesis of purines under possible primitive earth conditions. I. Adenine from hydrogen cyanide |journal=Archives of Biochemistry and Biophysics |volume=94 |issue=2 |pages=217–27 |doi=10.1016/0003-9861(61)90033-9 |pmid=13731263}}</ref> Oró found that several amino acids were also formed from HCN and ammonia under those conditions.<ref>{{cite journal |vauthors=Oró J, Kamat SS |date=April 1961 |title=Amino-acid synthesis from hydrogen cyanide under possible primitive earth conditions |journal=Nature |volume=190 |issue=4774 |pages=442–3 |bibcode=1961Natur.190..442O |doi=10.1038/190442a0 |pmid=13731262 |s2cid=4219284}}</ref> Experiments conducted later showed that the other [[Nucleobase|RNA and DNA nucleobases]] could be obtained through simulated prebiotic chemistry with a [[reducing atmosphere]].<ref>{{cite book |author=Oró J |title=Origins of Prebiological Systems and of Their Molecular Matrices |publisher=New York Academic Press |year=1967 |editor=Fox SW |pages=137}}</ref><ref>{{Cite journal |last1=Ferus |first1=Martin |last2=Pietrucci |first2=Fabio |last3=Saitta |first3=Antonino Marco |last4=Knížek |first4=Antonín |last5=Kubelík |first5=Petr |last6=Ivanek |first6=Ondřej |last7=Shestivska |first7=Violetta |last8=Civiš |first8=Svatopluk |date=2017-04-25 |title=Formation of nucleobases in a Miller–Urey reducing atmosphere |journal=Proceedings of the National Academy of Sciences |language=en |volume=114 |issue=17 |pages=4306–4311 |doi=10.1073/pnas.1700010114 |issn=0027-8424 |pmc=5410828 |pmid=28396441 |bibcode=2017PNAS..114.4306F |doi-access=free }}</ref> Other researchers also began using [[Ultraviolet|UV]]-[[photolysis]] in prebiotic schemes, as the UV flux would have been much higher on early Earth.<ref>{{Cite journal |last1=Canuto |first1=V. M. |last2=Levine |first2=J. S. |last3=Augustsson |first3=T. R. |last4=Imhoff |first4=C. L. |date=1983-06-01 |title=Oxygen and ozone in the early Earth's atmosphere |url=https://dx.doi.org/10.1016/0301-9268%2883%2990068-2 |journal=Precambrian Research |series=Development and interactions of the Precambrian atmosphere, lithosphere and biosphere: results and challenges |volume=20 |issue=2 |pages=109–120 |doi=10.1016/0301-9268(83)90068-2 |bibcode=1983PreR...20..109C |issn=0301-9268|url-access=subscription }}</ref> For example, UV-photolysis of water vapor with [[carbon monoxide]] was found to yield various [[Alcohol (chemistry)|alcohols]], aldehydes, and [[organic acid]]s.<ref>{{cite journal |last1=Bar-Nun |first1=Akiva |last2=Hartman |first2=Hyman |year=1978 |title=Synthesis of organic compounds from carbon monoxide and water by UV photolysis |url=https://doi.org/10.1007%2FBF00931407 |journal=Origins of Life |volume=9 |issue=2 |pages=93–101 |bibcode=1978OrLi....9...93B |doi=10.1007/BF00931407 |pmid=752138 |s2cid=33972427|url-access=subscription }}</ref> In the 1970s, [[Carl Sagan]] used Miller-Urey-type reactions to synthesize and experiment with complex organic particles dubbed "[[tholin]]s", which likely resemble particles formed in hazy atmospheres like that of [[Titan (moon)|Titan]].<ref name="Sagan-1979">{{Cite journal |last1=Sagan |first1=Carl |last2=Khare |first2=B. N. |date=1979 |title=Tholins: organic chemistry of interstellar grains and gas |url=https://www.nature.com/articles/277102a0 |journal=Nature |language=en |volume=277 |issue=5692 |pages=102–107 |doi=10.1038/277102a0 |bibcode=1979Natur.277..102S |s2cid=4261076 |issn=1476-4687|url-access=subscription }}</ref>