A broad general view of the chief mysteries and problems of astronomy is
given; possibility of life and intelligence on the moon and on Mars is discussed.
Sewall, Frank. Life on other planets as dei;d ~--~· £w::d.::->tl.J..>rg. f'.ti: :adelphia,
Swedenborg Scientific Association, 1911. 20 p.
Discussion of Swecienborg's description of planets in the solar system and their
inhabitants which he claimed to have visited by astral projection.
~hapley, Harlow. Extraterrestrial life. Astronautics, v. 5, Apr. 1960: 32-33,
50, 52.
It is postulated that homo sapiens as a species may be unique, but there is good
reason to expect that there are habitable planets with higher forms of life in
other soJar systems.
----- Riddle of God, man and outer space. Coronet, v. 49, Feb. 1961: 40-44.
Shklovskii, Josef S. and Carl Sagan. Intelligent life in the universe. Authorized
translation by Paula Fern. San Francisco, Holden-Day, 1966. 509 p.
Extension and revision by Sagan tJf Shklovskii •s Vselenna'Ia, zhizn ', :razum
[Universe, Life, Mind] (Moscow, 1963). Includes study oi earth's solar S~'S
tem, discussion of nature of life and its possible occurrence on other planets,
treatment of pos~ibility that advanced commuriicative technical civilizations
exist on planets of other stars, and discussion of problems in establishing con-
tact with civilizations separated from earth by interstellar distances.
Simpson, George G. The nonprevalence 0f humanoids. Science, v. 143, Feb. 21,
1964: 769-775.
States following conclusions: (1) there are certainly no humanoids elsewhere in
the solar system of which earth is part; (2) there is probably no extraterrestrial
life in the solar system of which 1~arth is part, but the possibility is not wholly
excluded as regards Mars; (3) there probably are forms of life on other plane-
tary systems somewhere in the universe, but if so it is unlikely that we can
learn anything whatever about them, even as to the bare fact of their real exis-
tence; (4) it is extremely improbable that such forms of life include humanoids,
and apparently as near impossible that we could ever communicate with them in
a meaningful and useful way if they did exist.
Slater, Alan E. The probability of intelligent life evolving on a planet. In VIIIth
International Astronautical Congress, Barcelona, 1957. Proceedings. Vienna,
Springer-Verlag, 1958. p. 395-402.
Report traces briefly the evolution of the human species from primitive life
forms and shows that the differentiation thai eventually led to man was far from
inevitable. Conckdes that it seems imprcbable that other forms of intelligent
life will be found by voyagers through spacr..
297