Strugholci, Hubertus. The possibilities of an inhabitable extraterrestrial environ-
ment reachable from the earth. The journal of aviation medicine. v. 28,
MARS
Oct. 1957: 507-512.
Ecologkal factors indispensible for the existence of terrestrial forms of life
are presented. Each planet in our solar system is e.xamined in the light of
these factors. and a habih\lJility index obtained. The possibility of life already
existing on Mars is discussed.
Abbot, C. G. The habitability of Venus, Mars, and other worlds. In
Annual report of the Board of Regents of the Smithsonian Institution
for the year ending June 30, 1920. Washington, D. C., U. S. Govt.
Print. Off., 1922. p. 165-171.
Considers the probability of the existence of intelligent life on
heavenly bodies other than the ea::-th and discusses means of com-
municating with the nearer planets.
Aitken, R. G. Why povular inter€'st in Mars: Leailets of the Astro-
nomical Society of the Pacific, v. 2, July 1925: 3-6.
Antoncadi, E. M. The planet Mars. Sky, magazine of cosmic news,
v. 31, July 1939: 6-7, 22.
Asimov, Isaac. The wellspriugs of life. New York, Abelard-Schuman,
1960, 233 p.
In so vast a universe, it is possible there are billions of "earth type"
planets. Mars is the only observable planet which may providE a
hd.bitat suitable for life.
Bennett, Dorothy A. Men from Mars. The sky, v. 3, Dec. 1938: 8-9.
Present knowiedge of conditions on Mars is reviewed to support author's
certitude that a Martian invasion is out of the question.
Bongers, Leonard H. Is there life on Mars? Space/aeronautics, v. 40,
Aug. 1963: 86-88.
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