File spoon-archives/bhaskar.archive/bhaskar_2001/bhaskar.0101, message 90


Date: Tue, 30 Jan 2001 21:16:05 +0000
Subject: BHA: Godstuff?


   

     
 
 
 We are stardust - perhaps - says Nasa 
Discovery 'implies life could be everywhere in the universe'

Special report: space exploration

Tim Radford, science editor
Guardian [UK]

Tuesday January 30, 2001


Nasa scientists have fashioned some of the fabric of life - in the
conditions of deep space. 

Laboratory experiments have delivered some of the complex self-
assembling compounds necessary to make living cell tissue. 

The research, reported today in the Proceedings of the US National
Academy of Sciences, confirms that life on Earth could have been kick-
started by molecules from the freezing cold emptiness between the stars.
Their experiments yielded structures like the membranes that hold cells
together, and protect them from the outside world. 

"Scientists believe that the molecules needed to make a cell's membrane,
and thus for the origin of life, are all over space. This discovery
implies that life could be everywhere in the universe," said Louis
Allamandola, who led the research. 

The idea is at least 2,000 years old. The Roman poet Lucretius proposed
a universe swarming with the seeds of life, and 100 years ago the
Swedish chemist Arrhenius - who also predicted the greenhouse effect and
global warming - proposed the notion of panspermia: that the chemistry
of life existed in space. Astronomical research steadily confirmed the
presence of vital chemicals such as water, alcohol, methane,
formaldehyde, hydrogen cyanide and many others in the atmospheres of
distant planets and in interstellar clouds, and then found even more
complicated hydrocarbons and amino acids in meteorites from space. 

But life on Earth began at least 3.8bn years ago, and the leap from
organic chemistry to self-replicating organism is so huge that the
astronomer Sir Fred Hoyle proposed that life might have been delivered
by a passing comet. 

A team from the astrochemistry laboratory at the Nasa Ames research
centre and from the University of California at Santa Cruz replicated
the freezing vacuum of space in the laboratory and filled it with am
monia, carbon monoxide, carbon dioxide and methanol to form a thin ice.
They then exposed this ice to the harsh ultraviolet radiation that would
blast such a brew in space. 

"Sure, we expected that ultraviolet radiation would make a few molecules
that might have some biological interest, but nothing major," said Dr
Allamandola. "Instead, we found that this process transforms some of the
simple chemicals that are very common in space into larger mol ecules
which behave in far more complex ways. Ways which many people think are
critical for the origin of life, the point in our history when chemistry
became biology." 

The next step is to confirm that such molecules actually exist in space.
A Nasa space probe called Stardust is already on a 2bn mile journey to
an encounter with a comet called Wild-2. It will rendezvous with the
comet beyond the orbit of Mars, sail through its dust tail at 13,000
mph, catch fragments of the primordial material of the solar system and
bring them back to Earth in 2006. This might provide researchers with a
clear picture of how stardust became not only planets, but the creatures
on them. 

"Every year more than a hundred tons of extraterrestrial stuff falls on
the Earth, and much of it is in the form of organic material," said
Scott Sandford, one of the experimenters. 

"In the early life of our solar system, before the debris from its
formation was fully cleared away, these materials were deposited on the
Earth in far greater quantities than we see today." 
 
        
   
 Guardian Unlimited  Guardian Newspapers Limited 2001  
********


Astronomy goes Hegelian?

One astronomer on UK TV Channel 4's program, The Universe, January 29
2001, said that 'it is as though the universe has invented a way of
coming to know itself through us'.


Mervyn





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