The Case for Relic Life on Mars; The Search for Alien Life; Exclusive Online Issues; by Everett K. Gibson, Jr., David S. McKay, Kathie Thomas-Keprta and Christopher S. Romanek; 7 Page(s)

Of all the scientific subjects that have seized the public psyche, few have held on as tightly as the idea of life on Mars. Starting not long after the invention of the telescope and continuing for a good part of the past three centuries, the subject has inspired innumerable studies, ranging from the scientific to the speculative. But common to them all was recognition of the fact that in our solar system, if a planet other than Earth harbors life, it is almost certainly Mars.

Interest in Martian life has tended to coincide with new discoveries about the mysterious red world. Historically, these discoveries have often occurred after one of the periodic close approaches between the two planets. Every 15 years, Mars comes within about 56 million kilometers of Earth (the next approach will occur in the summer of 2003). Typically, life on Mars was assumed to be as intelligent and sophisticated as that of Homo sapiens, if not more so. (Even less explicably, Martian beings have been popularly portrayed as green and diminutive.)