Astronomical Origins of Life: Steps Towards Panspermia

360 Pages·2012·9.276 MB·English

by  B. Hoyle, N.C. Wickramasinghe

ASTRONOMICAL ORIGINS
OFLIFE
Steps Towards Panspermia
Edited by
F. HOYLE and N.e. WICKRAMASINGHE
Department ofA pplied Mathematics and Astronomy.
University College, Cardiff, u.K.
Reprinted from Astrophysics and Space Science
Volume 268, Nos. 1-3, 1999
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
Library ofCongress Cataloging-in-Publication Data
Hoyle, Fred, Sir.
Astronomical origins oflife : steps towards panspermia / by F. Hoyle and N.C. Wickramasinghe.
p.cm.
ISBN 978-94-010-5862-9 ISBN 978-94-011-4297-7 (eBook)
DOI 10.1007/978-94-011-4297-7
1. Life--Origin. 2. Cosmic grains. 1. Wickramasinghe, N. C. (Nalin Chandra), 1939-IT.
Title.
QH325 .H673 1999
576.8'8--dc2l
99-052672
Caver illustratian: Columns of cool interstellar hydrogen gas and dust in Ml6, the Eagle
Nebula. Reprinted with permis sion of NASA and the National Space Science Data Center,
USA. Credit: leff Hester and Paul Scowen (Arizona State University).
Printed an acid-free paper
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Originally published by Kluwer Academic Publishers in 2000
Softcover reprint of the hardcover 1s t edition 2000
No part of the material protected by this copyright notice may be reproduced Of
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TABLE OF CONTENTS
Preface VII
Pans pennia 2000
I. GENERAL CONSIDERATIONS
F. HOYLE and N.C. WICKRAMASINGHE I On a Possibly Fun
damental Principle in Chemistry as Viewed in a Cosmogonic
Context 21
F. HOYLE and N.C. WICKRAMASINGHEI Biological Activity in the
Early Solar System in its Outer Regions 33
F. HOYLE, N.C. WICKRAMASINGHE and H.D. PFLUG I An Ob-
ject within a Particle of Extraterrestrial Origin Compared with
an Object of Presumed Terrestrial Origin 43
F. HOYLE,N.C. WICKRAMASINGHEand S. AL-MUFTI/The Viab-
ility with Respect to Temperature of Micro-Organisms Incident
on the Earth's Atmosphere 45
S. AL-MUFTI, F. HOYLE and N.C. WICKRAMASINGHE I A Labor-
atory Experiment with Relevance to the Survival of Micro-
Organisms Entering a Planetary Atmosphere 51
F. HOYLE and N.C. WICKRAMASINGHE I Biological Evolution 55
F. HOYLE and N.C. WICKRAMASINGHE I Metallic Particles in
Astronomy 77
F. HOYLE and N.C. WICKRAMASINGHE I The Universe and Life:
Deductions from the Weak Anthropic Principle 89
N.C. WICKRAMASINGHE and F. HOYLE I Miller-Urey Synthesis in
the Nuclei of Galaxies 103
2. COSMIC ORGANIC POLYMERS
N.C. WICKRAMASINGHE I Formaldehyde Polymers in Interstellar
Space 111
V. VANYSEK and N.C. WICKRAMASINGHE I Formaldehyde Poly-
mers in Comets 115
D.A. MENDIS and N.C. WICKRAMASINGHE I Composition of
Cometary Dust: the Case against Silicates 125
F. HOYLE and N.C. WICKRAMASINGHE I Primitive Grain Clumps
and Organic Compounds in Carbonaceous Chondrites 129
iv
A. SAKATA, N. NAKAGAWA, T. IGUCHI, S. ISOBE, M. MOR
IMOTO, F. HOYLE and N.C. WICKRAMASINGHE / Spec
troscopic Evidence for Interstellar Grain Clumps in Meteoritic
Inclusions 133
F. HOYLE and N.C. WICKRAMASINGHE / Calculations of Infrared
Fluxes from Galactic Sources for a Polysaccharide Grain Model 137
3. COSMIC MICRO-ORGANISMS: INFRARED CHARACTERISATION
F. HOYLE, N.C. WICKRAMASINGHE, S. AL-MUFTI and A.H.
OLAVESEN / Infrared Spectroscopy of Micro-Organisms Near
3.4 Mm in Relation to Geology and Astronomy 157
F. HOYLE, N.C. WICKRAMASINGHE, S. AL-MUFTI, A.H.
OLAVESEN and D.T. WICKRAMASINGHE / Infrared Spec
troscopy over the 2.9-3.9 Mm Waveband in Biochemistry and
Astronomy 161
F. HOYLE, N.C. WICKRAMASINGHE and N.L. JABIR / 2.8-3.6Mm
Spectra of Micro-Organisms with Varying H20 Ice-Content 167
F. HOYLE, N.C. WICKRAMASINGHE and S. AL-MUFTI / Organo-
Siliceous Biomolecules and the Infrared Spectrum of the
Trapezium Nebula 173
F. HOYLE, N.C. WICKRAMASINGHE and S. AL-MUFTI / The
Spectroscopic Identification of Interstellar Grains 181
F. HOYLE and N.C. WICKRAMASINGHE / The Availability of
Phosphorus in the Bacterial Model of the Interstellar Grains 191
R.B. HOOVER, F. HOYLE, N.C. WICKRAMASINGHE, MJ.
HOOVER and S. AL-MUFTI / Diatoms on Earth, Comets,
Europa and in Interstellar Space 197
Q. MAJEED, N.C. WICKRAMASINGHE, F. HOYLE and S. AL-
MUFTI/ A Diatom Model of Dust in the Trapezium Nebula 225
N.C. WICKRAMASINGHE and F. HOYLE / Infrared Evidence for
Panspermia: An Update 229
4. EVIDENCE FROM INTERSTELLAR EXTINCTION
F. HOYLE and N.C. WICKRAMASINGHE / On the Nature of Inter-
stellar Grains 249
F. HOYLE and N.C. WICKRAMASINGHE / A Model for Interstellar
Extinction 263
F. HOYLE, N.C. WICKRAMASINGHE and S. AL-MUFTI / The Ul-
traviolet Absorbance of Presumably Interstellar Bacteria and
Related Matters 273
N.C. WICKRAMASINGHE, A.N. WICKRAMASINGHE and F.
HOYLE / The Case against Graphite Particles in Interstellar
Space 289
v
5. BIOGENIC AROMATIC MOLECULES IN SPACE
N.C. WICKRAMASINGHE, F. HOYLE and K. NANDY / Organic
Molecules in Interstellar Dust: A Possible Spectral Signature at
A2200 A? 295
F. HOYLE and N.C. WICKRAMASINGHE / Identification of the A
2200 A Interstellar Absorption Feature 301
F. HOYLE and N.C. WICKRAMASINGHE / A Unified Model for the
3.28 {l Emission and the 2200 A Interstellar Extinction Feature 305
N.C. WICKRAMASINGHE, F. HOYLE and T. AL-JUBORY / Aro-
matic Hydrocarbons in Very Small Interstellar Grains 311
N.C. WICKRAMASINGHE, F. HOYLE and T. AL-JUBORY /
An Integrated 2.5-12.5 {lm Emission Spectrum of Naturally
Occurring Aromatic
Molecules 317
F. HOYLE and N.C. WICKRAMASINGHE / Bioftuorescence and the
Extended Red Emission in Astrophysical Sources 321
6. COMETS AND LIFE
F. HOYLE and N.C. WICKRAMASINGHE / Comets, Ice Ages, and
Ecological Catastrophes 329
F. HOYLE and N.C. WICKRAMASINGHE / Comets - A Vehicle for
Panspermia 333
F. HOYLE and N.C. WICKRAMASINGHE / Some Predictions on the
Nature of Comet Halley 343
D.T. WICKRAMASINGHE, F. HOYLE, N.C. WTCKRAMASTNGHE
and S. AL-MUFTI / A Model of the 2-4 {lm Spectrum of Comet
Halley 349
N.C. WICKRAMASINGHE, M.K. WALLIS and F. HOYLE / Model-
ling the 5-30 {lm Spectrum of Comet Halley 355
N.C. WICKRAMASINGHE and F. HOYLE / Very Small Dust Particles
(YSDP'S) in Comet C/l996 B2 (Hyakutake) 365
N.C. WICKRAMASINGHE and F. HOYLE / The Astonishing Redness
of Kuiper-Belt Objects 369
N.C. WICKRAMASINGHE, F. HOYLE and D. LLOYD / Eruptions of
Comet Hale-Bopp at 6.5 AU 373
N.C. WICKRAMASINGHE and F. HOYLE / Infrared Radiation from
Comet Hale-Bopp 379
PREFACE
Living material contains about twenty different sorts of atom combined into a set
of relatively simple molecules. Astrobiologists tend to believe that abiotic mater
ial will give rise to life in any place where these molecules exist in appreciable
abundances and where physical conditions approximate to those occurring here
on Earth. We think this popular view is wrong, for it is not the existence of the
building blocks of life that is crucial but the exceedingly complicated structures in
which they are arranged in living forms. The probability of arriving at biologically
significant arrangements is so very small that only by calling on the resources
of the whole universe does there seem to be any possibility of life originating, a
conclusion that requires life on the Earth to be a minute component of a universal
system.
Some think that the hugely improbable transition from non-living to living mat
ter can be achieved by dividing the transition into many small steps, calling on a
so-called 'evolutionary' process to bridge the small steps one by one. This claim
turns on semantic arguments which seek to replace the probability for the whole
chain by the sum of the individual probabilities of the many steps, instead of by
their product. This is an error well known to those bookies who are accustomed to
taking bets on the stacking of horse races.
But we did not begin our investigation from this point of view. We began by
attempting to understand the data on the scattering and absorption of starlight by
interstellar dust particles. As the observations improved over the years we were led
gradually to a cosmic view of the origin of life, led first to clear evidence that a
major fraction of the dust is of an organic composition and then to the result that
the dust actually contains a biological component in the form of bacteria. Much of
this work appeared in the Cardiff Blue Preprint Series and was later published in
journals, mainly in Astrophysics and Space Science.
Microorganisms reproduce themselves at astonishing rates when the physical
and chemical conditions are favourable, so great indeed that there is no difficulty
in seeing how the entire universe could be suffused by microbial life. Those with
a dislike for this conclusion often argue that interstellar microorganisms would be
destroyed by ultraviolet light from stars. But there are several effective replies.
First, organisms are not so much destroyed by ultraviolet as deactivated. Their
genetic arrangements survive, and reactivation can be achieved simply by a re
directing of the switching of thymine bonds. Second, microorganisms are easily
viii PREFACE
shielded against ultraviolet light. Indeed molecular clouds in the galaxy are highly
effective in this respect, both in cutting out the glare of ultraviolet radiation and per
mitting the growth of protective mantles around the bacterial particles. And third,
the replicative power of microorganisms is so great that only a minute fraction of
them are required to survive in each generation. These replies seem collectively
more than adequate to answer this objection.
With the genetic components of life distributed widely throughout the universe,
it is a matter for each local environment to pick out the arrangements that fit the
particular circumstances. In a case like the Earth a complicated fitting together
of the components has occurred over the last several hundred million years, by
a process which biologists refer to as evolution. However the basic genes have
not been produced here. For those who believe otherwise there are problems. The
interclass differences between bears and horses are much greater than the interspe
cies differences among bears and horses taken separately. Yet it is the latter that
dominate the fossil record. Because the latter have indeed occurred on the Earth,
whereas the genes responsible for the class differences of bears and horses have
been externally driven and the record of their origin is not local.
Cardiff, July 1999 Fred Hoyle
Chandra Wickramasinghe
PANSPERMIA 2000
1. Early History
The idea that life is a cosmic phenomenon has a history spanning many centuries
and many cultures. In most ancient philosophies of the Orient - for instance in
Vedhic and Buddhist writings - the cosmic nature of life is taken for granted: It is
regarded as an inherent property of a Universe that is itself infinite, timeless and
eternal.
Ideas of a broadly similar character were prevalent in Classical Greece, as seen
for instance in the writings of Anaxarogas in the 5th Century Be. However the
viewpoint that eventually held sway in the West was one that was represented in
the philosophy of Aristotle (384-322BC). According to Aristotelian philosophy
life was supposed to arise from non-living matter spontaneously whenever and
wherever the right set of conditions arose. The concept is referred to as the theory of
spontaneous generation, and in one form or another it came to be deeply entrenched
in the Western world.
In its original form, with the limited techniques of observation and experiment
ation that were available in earlier times, the theory of spontaneous generation
may indeed have seemed to possess some degree of prima facie validity. The
sight of maggots crawling out of rotting meat and of fireflies emerging from dew
may have served as impressive visual testimony to the concept of spontaneous
generation. But upon closer inspection and more critical analysis the testimony
disappears. With the invention of the microscope, and following the classic exper
iments of Louis Pasteur in the late 1850's it became amply clear that the ancient
idea of spontaneous generation was simply wrong. Pasteur's work on the souring
of milk (Pasteur, l857a) and the fermentation of wine (Pasteur, l857b) showed
that microbial life had necessarily to be derived from pre-existing lifeforms of
a similar kind. That this is so for non-microscopic larger lifeforms is of course
obvious. After describing his classic experiments to the French Academy Pasteur
confidently declared that the theory of spontaneous generation 'will never recover
from this mortal blow' (Pasteur, 1860). Pasteur's experimental results were beyond
dispute; but he was sadly to be proved wrong in the way he judged the scientists
who came after him.
2 PANSPERMIA 2000
Science based on Cartesian reductionist principles, found it exceedingly diffi
cult to accept that mechanistic processes could account for a simple transition from
non-living to living matter. After nearly half a century of sophisticated laboratory
experiments scientists have not been able to disprove Pasteur's important conten
tion that life can only be derived from pre-existing life. Although many claims to
the contrary have been made from time to time they are all manifestly flawed. The
Urey-Miller experiments (Urey, 1952; Miller, 1953) of the mid-1950's showed how
amino acids and nucleotides might form from a mixture of inorganic gases (Oparin,
1953; Haldane, 1929), but such experiments do not come remotely near the de
sired goal of producing life from non-life. Nor do other more recent experiments
such as those of Imai et al. (1999) who reported the production of hexaglycine
under conditions thought to occur in terrestrial hot springs. Nor the experiments
of Bernstein et at. (1999) who showed that ultraviolet irradiation of polyaromatic
hydrocarbons in water ice leads to the production of some 'biologically relevant'
molecules such as alcohols, quinones and ethers. What is relevant for the origin of
life is not just the formation of the chemical building blocks, but the emergence of
highly specific arrangements of these molecules into structures such as enzymes.
It is the latter process that presents a taunting enigma to scientists of the present
day. Recent studies of Mushegian and Koonin (1996) involving the sequencing of
bacterial genomes have shown that a gene set coding for some 256 proteins may
be regarded as a minimal set needed for cellular life. Using our earlier argument
(Hoyle and Wickramasinghe, 1980) which gave a chance of random assembly of
a single enzyme from its components of about one part in 1020 we now arrive at a
probability of assembly of the minimal enzyme set of one part in 105120. The latter
number can be regarded as a measure of the minimum information content of life.
The simplest autonomous living cell with such a superastronomical information
content is an entire cosmos apart from amino acids strung into biologically inert
and irrelevant proteinoids.
The idea that the origin of life involved a progression of steps through an RNA
world, with each individual step assumed to be far less improbable than the final
hurdle, does little to solve the problem. A principle of biological determinism is
concealed here, the implication being that the final information content of life is
somehow contained in the laws of physics and is slowly unravelled in a sequence
of predetermined steps. Such an assumption has no empirical basis, however, and
so the idea has to be viewed with suspicion to say the least.
Pasteur's experiments in the 1850's and 1860's provided perhaps the most im
portant experimental basis for panspermia. Indeed this was a conclusion that was
reached quite early by the German physicist Hermann Von Helmholtz (1874) who
wrote thus:
'It appears to me to be fully correct scientific procedure, if all our attempts fail
to cause the production of organisms from non-living matter, to raise the ques
tion whether life has ever arisen, whether it is not just as old as matter itself, and
PANSPERMIA 2000 3
whether seeds have not been carried from one planet to another and have developed
everywhere where they have fallen on fertile soil ... .'
Sir William Thomson (later Lord Kelvin) expanded on Pasteur's paradigm:
'Dead matter cannot become living without coming under the influence of matter
previously alive. This seems to me as sure a teaching of science as the law of
gravitation ... '.
So if life had preceded the Earth, how had it arrived here and where had it
come from? Earlier in the 19th century the German physician R.E. Richter had
suggested that living cells might travel from planet to planet inside meteorites.
Richter, a physician, had only a scant knowledge of dynamics. This enabled the
German physicist 1. Zollner in the 1870's to raise seemingly valid technical objec
tions, and it needs hardly be said that such objections were eagerly seized upon by
orthodox opinion. But Lord Kelvin's superior mastery of dynamics allowed him
to see that there was nothing to Zollner's objections. In particular Kelvin noted
that evaporation from the outside of a large meteorite keeps its inside cool, thereby
reasserting the possibility that organisms could be carried from planet to planet
inside meteorites. In his presidential address to the 1871 meeting of the British
Association in Edinburgh, Lord Kelvin drew the following remarkably modem
picture (Thomson, 1871), advocating what could now be recognised as the theory
of planetary panspermia:
'When two great masses come into collision in space, it is certain that a large
part of each is melted, but it seems also quite certain that in many cases a large
quantity of debris must be shot forth in all directions, much of which may have
experienced no greater violence than individual pieces of rock experience in a
landslip or in blasting by gunpowder. Should the time when this earth comes into
collision with another body, comparable in dimensions to itself, be when it is still
clothed as at present with vegetation, many great and small fragments carrying
seeds of living plants and animals would undoubtedly be scattered through space.
Hence, and because we all confidently believe that there are at present, and have
been from time immemorial, many worlds of life besides our own, we must regard
it as probable in the highest degree that there are countless seed-bearing meteoric
stones moving about through space. If at the present instant no life existed upon the
earth, one such stone falling upon it might, by what we blindly call natural causes,
lead to its becoming covered with vegetation.'
2. Svante Arrhenius
The next facet in the story is associated with the Swedish Chemist and Nobel
laureate Svante Arrhenius (1908), whose book Worlds in the Making appeared in
English in 1908. Arrhenius' contribution rested on two main points, one good, one
not so good. The good point was that microorganisms possess unearthly properties,
properties that cannot be explained by natural selection against a terrestrial environ-