NASA has made a startling discovery that points to the possibility that a primitive form of microscopic life may have existed on Mars more than three billion years ago. ... It is a discovery that demands further scientific investigation. ... They will outline the step-by-step 'detective story' that explains how the meteorite arrived here from Mars, and how they set about looking for evidence of long-ago life in this ancient rock. ... NASA Headquarters, . ... Mars Life from Mars: The Discovery . ...