306 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1964 



wavelengths at which these features are observed are specific for hydro- 

 carbons and aldehydes ; and no reasonable inorganic materials absorb 

 at these wavelengths. The presence of hydrocarbons and aldehydes 

 on Mars may provide a key to Martian biochemistry, but it is also 

 possible — if less likely — that they are irrelevant to the question of life 

 on Mars. We have already seen that complex organic molecules can 

 be formed in the absence of living systems. 



While none of the pieces of evidence is convincing by itself, together 

 they are suggestive of at least simple life forms on Mars, composed 

 of familiar organic substances, dependent upon water, proliferating 

 in the springtime, and covering a major fraction of the planetary 

 surface. But we are far from sure. 



So we must, after all, go to Mars. The plans are already being 

 formulated, both in the United States and m the Soviet Union, for 

 these voyages of discovery and high scientific adventure which may, 

 perhaps, begin before the decade is out. Instrmnents have been de- 

 signed, prototypes built and tested, to land in preselected locales, search 

 for the presence of life, and radio the news back to Earth. Television 

 cameras will see what there is to see — perhaps only sand dunes, but 

 perhaps . . . foliage? . . . fossils? . . . footprints? Coupled with 

 microscopes, they will seek out microorganisms. Culture media will 

 be automatically inoculated with soil samples, and then monitored. 

 Do Martian organisms eat terrestrial foodstuffs ? 



In various forms, life has existed on the planet Earth for some 

 4 billion years. Thus, on a random basis, the probability of being 

 alive during just that decade when the first definitive study is made 

 of life beyond the Earth is about one-millionth of a percent. To seek 

 the beings of other worlds is the rarest of adventures — an adventure 

 we will all be fortunate enough to share. 



