To the Editor:—
Your editorial on polluting the universe (197:1096. 1966) expresses appropriate concern over the possibility that terrestrial organisms may interfere with experiments to detect life on other planets, particularly Mars. However, it is unlikely that terrestrial organisms could survive (except in a dormant state) and multiply to overwhelm indigenous life on Mars, where anaerobic conditions, intense solar radiations, extreme dryness, and subzero temperatures prevail.On the other hand, Martian life, if it exists, must be sufficiently hardy to withstand the driest and coldest conditions on our own planet. There is no guarantee that such life would not find moderate climates even more hospitable. When planning expeditions into space, perhaps we should consider that our own planet could be invaded—not by little green men or bug-eyed monsters, but by biochemically complex, primitive forms of life possessing a superior ability to survive under some conditions existing on the Earth.