Editing Martian meteorite (section)

== History ==
By the early 1980s, it was obvious that the SNC group of meteorites (Shergottites, Nakhlites, and Chassignites) were significantly different from most other meteorite types. Among these differences were younger formation ages, a different oxygen isotopic composition, the presence of aqueous weathering products, and some similarity in chemical composition to analyses of the Martian surface rocks in 1976 by the [[Viking program|Viking landers]]. Several scientists suggested these characteristics implied the origin of SNC meteorites from a relatively large parent body, possibly Mars.<ref name=Smith>{{cite journal |author=Smith, M.R. |author2=Laul, J. C. |author3=Ma, M. S. |author4=Huston, T. |author5=Verkouteren, R. M. |author6=Lipschutz, M. E. |author7=Schmitt, R. A. |bibcode=1984LPSC...14..612S |doi=10.1029/JB089iS02p0B612 |title=Petrogenesis of the SNC (Shergottites, Nakhlites, Chassignites) Meteorites: Implications for Their Origin From a Large Dynamic Planet, Possibly Mars. |journal=Journal of Geophysical Research |volume=89 |issue=S02 |pages=B612–B630 |date=February 15, 1984 }}</ref><ref>{{cite journal |author=Allan H. Treiman |author2=Michael J. Drake |author3=Marie-Josee Janssens |author4=Rainer Wolf |author5=Mitsuru Ebihara |doi=10.1016/0016-7037(86)90389-3 |title=Core formation in the Earth and Shergottite Parent Body (SPB):Chemical evidence from basalts |journal=Geochimica et Cosmochimica Acta |volume=50 |issue=6 |pages=1071–1091 |date=January 1986  |bibcode=1986GeCoA..50.1071T }}</ref> 

Then in 1983, various trapped gases were reported in impact-formed glass of the EET79001 shergottite, gases which closely resembled those in the Martian atmosphere as analyzed by Viking.<ref>{{cite journal|last=Bogard|first=D. D.|author2=Johnson, P.|title=Martian gases in an Antarctic meteorite|journal=Science|date=1983|volume=221|pages=651–654|bibcode = 1983Sci...221..651B |doi= 10.1126/science.221.4611.651|pmid=17787734|issue=4611|s2cid=32043880}}</ref> These trapped gases provided direct evidence for a Martian origin. In 2000, an article by Treiman, Gleason and Bogard gave a survey of all the arguments used to conclude the SNC meteorites (of which 14 had been found at the time) were from Mars. They wrote, "There seems little likelihood that the SNCs are not from Mars. If they were from another planetary body, it would have to be substantially identical to Mars as it now is understood."<ref name="pass48_12-14"/>