Abstracts on planetary studies and the search for extraterrestrial life are presented. Studies of the Jovian atmosphere were conducted. An assessment of the prospects for life on Mars is presented. And, the the means of contacting extraterrestrial civilizations is discussed

Khare, B. N.

Sagan, C.

English

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https://ntrs.nasa.gov/search.jsp?R=19760018712 2020-03-22T14:14:10+00:00Z
26
('+A .`+—C-^-1+3177)	 c-_xui31JLuGY ANE TH`E ;RIGIN	 N76— 5800
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CSCL Jai	 U`dCL AS
v3/55 42738
CORNELL UNIVERS ITY
Center ,for Radiophysics and Space Research)
ITHAG, N.Y.
f^
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n CRSR. 6.37
ANNUAL STATUS REPORT
to the
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
under
NASA Grant NGR 33-010-101
0EXOBIOLOGY AND THE ORIGIN OF LIFE ^^' 
J 4k
^.	 -
Principal Investigator: Prof. Carl S	 n`	 ^+
Co-Investigator: Dr. B. N. Kh nj
MAY 1976	 ^V1him71.tiQ
,^ i
TABLE OF CONTENTS
A. Particles, Environments and Possible Ecologies
in the Jovian Atmosphere	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 1
B. Cyclic Octc.tomic Sulfur:	 A Possible Infrared
and Visible Chromophore in the Clouds
of	 Jupiter	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 3
C. On the Temperature Dependence of Possible
S8 Infrared Bands in Planetary Atmospheres
	
.	 .	 .	 .	 .	 .	 3
D. The Prospects for Life on Mars:
	
A Pre-Viking
Assessment	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 4
E. The Canals of Mars:	 An Assessment After
Mariner 9 	.	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 5
F. The Recognition of Extraterrestrial Intelligence	 .	 .	 .	 .	 5
G. Pattern Recognition and Zeta Reticuli	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 7
H. The	 Zeta Reticuli Affair	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 7
I. An Introduction to the Problem of Cosmic
Communication	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 7
J. Biogenesis, Abiogenesis,	 Biopoesis and All That .	 .	 .	 .	 .	 8
K. The Search for Extraterrestrial Intelligence	 .	 .	 .	 .	 .	 .	 8
L. Miscellaneous
	
.	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 .	 8
M
1COMPLETED WORK
Following is a partial list of recent papers published
or in press in 1975-76 and supported wholly or in part by
NASA Grant NGR 33-010-101. All authors are affiliated with
the Laboratory for Planetary Studies except for paper 4
which is jointly authored by Carl Sagan and Joshua Lederberg
of Stanford University.
(1) Particles, Environments and Possible Ecologies in
the Jovian Atmosphere (Astrophysical Journal Supple-
ment, to be published.)
The eddy diffusion coefficient is estimated as a function
of altitude, separately for the Jovian troposphere and meso-
sphere. The growth-rate and motion of particles is estimated
for various substances: the water clouds are probably nuc-
leated by NH4Cl, and sodium compounds are likely to be absent
at these levels. Complex organic molecules produced by the
Ly a photolysis of methane may be the absorbers in the lower
mesosphere which account for the low reflectivity of Jupiter
in the near ultraviolet. The optical frequency chromophores
s TI
e
2are localized at or .just below the Jovian tropopause. Candi-
date chromophore molecules must satisfy the condition that
they are produced sufficiently rapidly that convective pyroly-
sis maintains the observed chromophore optical depth. Organic
molecules produced by ultraviolet light and polymeric sulfur
seem to fail this test, even when a slow, deep circulation pat-
tern, driven by latent heat, is present. However, Jovian
photoautotrophe in the upper troposphere satisfy this
condition well, even with fast circulation, assuming only
biochemical properties of comparable terrestrial organisms.
Unless buoyancy can be achieved, a hypothetical organism
drifts downwards and is pyrolyzed. An organism in the
form of a thin, gas-filled balloon can grow fast enough to
replicate if (i) it can survive at the low mesospheric
temperatures, or if (ii) photosynthesis occurs in the
troposphere. If hypothetical organisms are capable of
slow, powered locomotion and coalescence, they can grow
large enough to achieve buoyancy. Airborne ecological niches
for sinkers, floaters and hunters a ppear to exist in the
Jovian atmosp'Liere .
{A draft of the penultimate version of this paper is at-
tacked as Appendix B.}
3(2) Cyclic Octatomic Sulfur: A Possible Infrared and
Visible Chromophore in the Clouds of Jupiter,
Science, Volume i89, pp. 722-723, 1975.
A brown polymeric material, produced under simulated
Jovian conditions, is composed primarily of cyclic-octatomic
sulfur, although a range of complex_ organic compounds is
also present. The polymeric sulfur, produced from the
ultraviolet photolysis of hydrogen sulfide, exhibits
its strongest band at 465 reciprocal centimeters, in fair
agreement with the frequency of the unidentified Jovian
absorber recently announced by Houck et al. Polymeric
octatomic sulfur may be an important constituent of the
Jovian clouds.
(3) On the Temperature Dependence of Possible S8
Infrared Bands in Planetary Atmospheres, Icarus,
in press.
Measurements of the temperature dependence between 77
and 333K of the infrared spectrum of cyclic octatomic sulfur
4
suggest that the 23 um Joviar, feature very tentatively iden-
tified by Houck et al. k1975) is not due to S 8 ; and that the
— —
s
4temperature dependence of the frequency of the 835 cm-1 band
of S8 may be a useful temperature marker in planetary studies.
(4) The Prospects for Life on Mars: A Pre-Viking
Assessment, Icarus, in press.
Mariner 9 has provided a refutation or reinterpretation
of several historical claims for Martian biology, and has
permitted an important further characterization of the
environmental constraints on possible Martian organisms.
Four classes of conceivable Martian organisms are identi-
fied, depending on the environmental temperature, T, and
water activity, a w : Class I, high T, high a w ; Class II,
low T, high aw ; Class III, high T, low aw ; and Class IV,
low T, low aw . The Viking lander biology experiments are
essentially oriented towards Class I organisms; although
arguments are given for the conceivable presence on Mars
of organisms in any of the four classes. Organisms which
extract their water requirements from hydrated minerals
or from ice are considered possible on Mars, and the high
ultraviolet flux and low oxygen partial pressure are con-
sidered to be negligible impediments to Martian biology.
5Large organisms, possibly detectable by the Viking lander
cameras, are not only possible on Mars, they may be favored.
The surface distribution of Martian organisms and future
search strategies for life on Mars are discussed.
(5) The-Canals of Mars: An Assessment after
Mariner 9, Icarzis, Volume 25, pp. 602-612,
1975.
The Lowellian canal network has been compared with the
results of Mariner 9 photography of Mars. A small number
of canals may correspond to rift valleys, ridge systems,
crater chains, and linear surface albedo markings. But
the vast bulk of classical canals correspond neither to
topographic nor to albedo features, and appear to have no
relation to the real Martian surface.
(6) The Recognition of Extraterrestrial Intelligence,
Proceedings of the Royal Society of London,
B 189, pp. 143-153, 1975.
A necessary but not sufficient condition for the
recognition of extraterrestrial intelligence is a signifi-
cant departure from thermodynamic equilibrium. This can
4
n
6clearly be discerned in the inverse problem of the detec-
tion of terrestrial intelligence from a distance. Photo-
graphy of the Earth in reflected sunlight reveals no clear
sign of life until 100 meters resolution is achieved, at
which point the agricultural and urban reworking of the
Earth's surface in rectangular arrays first becomes obvious.
This pattern is however detectable only over interplanetary
distances. Mars exhibits no such patterns. The departure
from radiative equilibrium -- represented by radio, tele-
vision and radar technology -- in the microwave spectrum
of the Earth is by contrast easily detectable over inter-
stellar distances. Even with a technology no more advanced
than our own, a civilization on a planet of a nearby
star could easily determine, by autocorrelation techniques,
the artificiality of these radio signals. Intentional
interstellar radio messages should be detected and de-
crypted far more readily. Possible message contents for
interstellar discourse of a modulated signal at any
accessible frequency include (1) m-dimensional imagery
represented by the transmission of numbers which are the
products of m prime numbers; and (2) the use of a common
mathematics, physics or astronomy to convey a range of in-
formation on more difficult subjects. The only direct
r
I
7attempts to date to communicate with extraterrestrial
intelligence	 the plaques aboard the Pioneer 10 and 11
spacecraft -- are briefly discussed.
(7) Pattern Recognition and Zeta Reticuli, Astronomy,
Volume 3, Number 7, pp. 39-40, 1975.
(8) The Zeta Reticuli Affair Astronomy Volume 3,
Number 9, pp. 16-17, 1975.
The supposed agreement between the "star map" of the
Hill case with a map of the distribution of nearby stars of
solar spectral type from the Gliese catalog is shown to be no
better than is to be expected by chance, and therefore
not good evidence of visitations to the Earth by extra-
terrestrial civilizations. Prominent among the statistical
errors in some other discussions on this matter is the
fallacy of the enumeration of favorable circumstances.
(9) An Introduction to the Problem of Cosmic
Communication, in Cosmic Communication,
C. Ponnamperuma and A.G.W. Cameron, eds.,
Boston, Houghton Mifflin, 1975.
0
8(10) Biogenesis, AbiogenesYs, Blopoesis and All That,
Origins of Life, Volume 6, page 577, 1975.
(11) The Search for Extraterrestrial Intelligence,
Scientific American, Volume 232,
pp. 80-89, 1975. Available as Scientific American
offprint Number 347, San Francisco, W.H. Freeman
and Company, 1976. Reprinted as "En Busca de la
Inteligencia Extraterrestre" in Revista de Occidente
November, 1975, pp. 84-92 (Madrid).
In addition, substantial progress was made in several
other areas treated more fully in the body of the renewal
proposal, but including: extensive gas chromatograph/mass
spectrometer studies of brown polymeric material produced
both by electric discharge and by ultraviolet light ir.
experiments on prebiological organic chemistry and on
the present organic chemistry of the atmosphere of Jupiter;
an analysis of the differential reflectivity of Jovian
bands and belts in order to distinguish between candidate
chromophores including sulfur compounds and complex organic
polymers; and the execution and analysis of an extensive
A
I:
s
•
9series of observations at the Arecibo Radio Observatory
for possible radio messages from extraterrestrial civiliza- 	 4
tions both within our Galaxy and in other galaxies.
During the past grant year the principal investigator
has served as Chairman of the Division for Planetary Sciences
of the American Astronomical Society; as Chairman of the
Astronomy Section of the American Associaticn for the Ad-
vancement of Science; and was elected to the Physical Sciences
4	 Committee, SPAC, NASA Headquarters. He served as Jacob
Bronowski Lecturer at the University of Toronto, as Royal
Institution Lecturer at the Royal Institution in London and
as Danz Lecturer at the University of Washington. He also
rec eived three honorary Doctor of Science degrees, from
Rensselaer Pol y technic Institute, Denison University, and
Skidmore College. Among his popular works published which
relate to the subject matter of this grant were British,
German, French, Spanish, Dut,:h and Italian editions of The
cosmic Connection: An Extraterrestrial Perspective, and a
British edition of Other Worlds; as well as "The Solar
System" (Scientific American, Vol. 233, pp. 22-31) and
"The Planets" in Man and Cosmos:	 The Guggenheim Lectures
(New York, W.W. Norton), pp. 68-100.
t^


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