The issue of Science magazine that contained the report by David McKay of NASA’s Johnson Space Center and a group of scientists was quite ordinary, even if McKay and company’s article was not. Methodically, they laid out the facts of the case: a large rock was found by an Antarctic expedition; further studies suggested it was of Martian origin; and on a thorough investigation, it was believed, there was enough evidence to suggest once-existing primitive life.

On this day, August 6, in 1996 the Science magazine article by McKay was published. The scientists used very dry, technical language, careful not to slip into sensationalism and suggest the possibility of “little green men.”

Examination of the rock showed it is similar in composition to other meteorites from the planet, and had traces of the Martian atmosphere. Water is a necessary precondition to any form of life as we know it, and somewhere over its 4.5 billion year history the rock was likely touched by water — carbonate minerals inside the fossil were deposited that way. And finally, within the carbonate deposits there was traces of tube and rope-like structures, which are similar to the shapes of some microbes on earth. There is still considerable debate on the interpretation of the facts, but the theory of little green men may hold water yet.