Science: Life on Mars

Ever since Galileo stuck a couple of lenses in a length of pipe and got a glimpse of the solar system, scientists and storytellers have worked overtime peopling the outer universe with living creatures. It is high time, says Dr. Hubertus Strughold of the U.S. Air Force School of Aviation Medicine, "to raise the question of life on other planets to the biological plane where it belongs ..."

In a new book, The Green and Red Planet (University of New Mexico Press; $4), Dr. Strughold raises the question with restraint. Mercury, says he, is far too hot to bother with. From Jupiter...