Analyses of sulfur isotopes have been used as evidence against life on the Moon, because the sulfides in lunar rocks have
A) an isotope composition most similar to marine sulfate, which is enriched in ³⁴S.
B) an isotope composition most similar to marine mud, which is enriched in ³⁴S.
C) an isotope composition most similar to igneous rocks.
D) exactly equal amounts of ³⁴S and ³²S.

Question

Quizplus · Accepted Answer

Sulfides in lunar rocks have an isotope composition most similar to igneous rocks, indicating a non-biological, geological origin, which contrasts with the isotopic signatures that would suggest biological processes.

Analyses of Sulfur Isotopes Have Been Used as Evidence Against