Possibility Of Life Forms In Space Examined

Press, Volume CVIII, Issue 31774, 3 September 1968, Page 8

Possibility Of Life Forms In Space Examined

(By ROBERT C. COWEN, natural science editor o/ the “Christian Science Monitor’’)

When an astronaut heads for space he needs elaborate gear to take along a bit of earth’s friendly environment.

But Dr David B. Cudaback thinks that, just possibly, some form of life mav flourish in space without such elaborate coddling.

Until recently, scientists viewed organic life as fragile and improbable. Now they consider its widespread occurrence almost Inevitable. This, the second of two articles, raises the question: Might life even exist in the space between the stars?

As far as facts go, the University of California astronomer admitted this to be no more than colourful thinking. Yet he has found evidence that the near-vacuum between the stars may be more hospitable than experts have thought for molecules with the kind of complexity associated with the chemistry of organic life. If life forms themselves don’t thrive out there, he said, perhaps some of the chemicals from which organic life arises do. When stars and planets condense out of interstellar matter, some of these chemicals may form part of the original atmosphere of a planet. Thus, the primordial materials from which earthly life arose may have existed from our planet’s beginning. Three Basic Needs Discussing this, he said: “It begins to look to me as though you don’t need as cosy a place as a planet for life. Certainly you don't need it for complex molecules.” “I’m not an expert in biochemistry,” he said, “but, in my view, life needs basically just complex molecules, an energy source, and a place to get rid of unwanted energy, an energy sink. A biochemist might laugh at this. But this is what I think. “A remarkable thing about the universe is that the energy sources and sinks are widely distributed. Anywhere in the universe it is easy to

get an energy source (a star say) on one side and a sink (space) where you can throw energy away.” Looked at from a physical

viewpoint, organic life is a thermodynamic process. It takes in energy, uses some of it, and throws away some as waste heat or in some other form.

According to basic thermodynamic laws, the greater the difference between the temperatures at which energy is taken in and at which it is rejected, the more efficient is the process. “Perhaps it is too naive a view to think life needs these protective conditions. We have evolved in ways such that /we need this cosy environment But is it fair to assume any organism must have such protection?" Dust Grains Effective Generally, biologists have believed it is necessary to have material above freezing for life processes to go on. Dr Cudaback reserved judgment on this. “You need this on ear.th,” he said, “I'm not sure you need it for life. You can

build computers that operate well-below freezing. But I don’t know much about this. “Let me go back to what I do know. To form complex molecules, you need a good collision rate between molecular elements and you need to get rid of the energy liberated when these elements link together. It’s hard to satisfy either of these needs in three dimensional space between the stars. “But it is much easier for molecular elements to get together in the two dimensions of the surfaces of dust grains. Also, calculations show that, often, the structures are physically unable to get rid of energy when they

join up in space. So they tend to break up again. But they can easily transfer the unwanted energy to a dust grain by vibration.” If there are complex molecules in space, then, Dr Cudaback would look for them on the surface of grains of interstellar dust. He thinks there is some evidence that these molecules exist. Certain wavelengths are absorbed by interstellar matter from light reaching Earth from outer space. Some of this absorption cannot be easily explained by atomic effects or by action of simple molecules. “Wishful Thinking” By elimination. Dr Cudaback said, this suggests the existence of complicated molecular structures. At least this seems plausible. It's the most definite scientific fact he has to go on in thinking about the prospects for life chemistry in space. “I am trying to avoid talking about life (n this case,” he said. “I am talking about

what we can measure, the existence of complex mole cules in space. Of course, this relates to life.

“Here is my hypothesis, my wishful thinking. When a collection of complex molecules in space collapses in star and planet formation, it may result in planetary conditions that give a good start for life.” Whether or not Dr Cudaback’s “wishful thinking" turns out to be correct, and whether or not organic life or its precursors do in fact exist in outer space, his ideas show how far scientists’ thinking has come from the belief that life is a statistically improbable thing.