Three Isotopes of Oxygen in Lunar Samples - The Same as Earth or Different?

[摘要] One of the most important measurements that can be made for any extraterrestrial sample is determination of the relative abundance of O-16, O-17 and O-18. To make the comparison, investigators report their results as delta (d) values compared to terrestrial delta O-17 vs delta O-18 for a suite of specimens because for any given reservoir, i.e. a planetary parent body such as the Earth or Mars, the numbers should define a line of gradient approximately one half. Different bodies should be identified from their delta O-17 which has traditionally been defined by the equation delta O-17 = delta O-17 - (a constant, ca. 0.52)delta O-18.

[发布日期] 2014-03-17

[学科分类] 天文学(综合)