[meteorite-list] Could Life Have Started in a Lump of Ice?

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 7 Nov 2008 14:35:26 -0800 (PST)
Message-ID: <200811072235.OAA11316_at_zagami.jpl.nasa.gov>

http://www.esf.org/research-areas/physical-and-engineering-sciences/news/ext-news-singleview/article/very-cold-ice-films-in-laboratory-reveal-mysteries-of-universe-516.html

Very cold ice films in laboratory reveal mysteries of universe
Could life have started in a lump of ice?
European Science Foundation
November 5, 2008

The universe is full of water, mostly in the form of very cold ice films
deposited on interstellar dust particles, but until recently little was
known about the detailed small scale structure. Now the latest quick
freezing techniques coupled with sophisticated scanning electron
microscopy techniques, are allowing physicists to create ice films in
cold conditions similar to outer space and observe the detailed
molecular organisation, yielding clues to fundamental questions
including possibly the origin of life. Researchers have been surprised
by some of the results, not least by the sheer beauty of some of the
images created, according to Julyan Cartwright, a specialist in ice
structures at the Andalusian Institute for Earth Sciences (IACT) of the
Spanish Research Council (CSIC) and the University of Granada in Spain.

Recent discoveries about the structure of ice films in astrophysical
conditions at the mesoscale, which is the size just above the molecular
level, were discussed at a recent workshop organised by the European
Science Foundation (ESF) and co-chaired by Cartwright alongside C.
Ignacio Sainz-Diaz, also from the IACT. As Cartwright noted, many of the
discoveries about ice structures at low temperatures were made possible
by earlier research into industrial applications involving deposits of
thin films upon an underlying substrate (ie the surface, such as a
rock, to which the film is attached), such as manufacture of ceramics
and semiconductors. In turn the study of ice films could lead to
insights of value in such industrial applications.

But the ESF workshop???s main focus was on ice in space, usually formed at
temperatures far lower than even the coldest places on earth, between 3
and 90 degrees above absolute zero (3-90K). Most of the ice is on dust
grains because there are so many of them, but some ice is on larger
bodies such as asteroids, comets, cold moons or planets, and
occasionally planets capable of supporting life such as Earth. At low
temperatures, ice can form different structures at the mesoscale than
under terrestrial conditions, and in some cases can be amorphous in
form, that is like a glass with the molecules in effect frozen in space,
rather than as crystals. For ice to be amorphous, water has to be cooled
to its glass transition temperature of about 130 K without ice crystals
having formed first. To do this in the laboratory requires rapid
cooling, which Cartwright and colleagues achieved in their work with a
helium "cold finger" incorporated in a scanning electron microscope to
take the images.

As Cartwright observed, ice can exist in a combination of crystalline
and amorphous forms, in other words as a mixture of order and disorder,
with many variants depending on the temperature at which freezing
actually occurred. In his latest work, Cartwright and colleagues have
shown that ice at the mesoscale comprises all sorts of different
characteristic shapes associated with the temperature and pressure of
freezing, also depending on the surface properties of the substrate.
For example when formed on a titanium substrate at the very low
temperature of 6K, ice has a characteristic cauliflower structure.

Most intriguingly, ice under certain conditions produces biomimetic
forms, meaning that they appear life like, with shapes like palm leaves
or worms, or even at a smaller scale like bacteria. This led Cartwright
to point out that researchers should not assume that lifelike forms in
objects obtained from space, like Mars rock, is evidence that life
actually existed there. "If one goes to another planet and sees small
wormlike or palm like structures, one should not immediately call a
press conference announcing alien life has been found," said Cartwright.
On the other hand the existence of lifelike biomimetic structures in ice
suggests that nature may well have copied physics. It is even possible
that while ice is too cold to support most life as we know it, it may
have provided a suitable internal environment for prebiotic life to have
emerged.

"It is clear that biology does use physics," said Cartwright. "Indeed,
how could it not do? So we shouldn't be surprised to see that sometimes
biological structures clearly make use of simple physical principles.
Then, going back in time, it seems reasonable to posit that when life
first emerged, it would have been using as a container something much
simpler than today's cell membrane, probably some sort of simple vesicle
of the sort found in soap bubbles. This sort of vesicle can be found in
abiotic systems today, both in hot conditions, in the chemistry
associated with 'black smokers' on the sea floor, which is currently
favoured as a possible origin of life, but also in the chemistry of sea
ice."

This is an intriguing idea that will be explored further in projects
spawned by the ESF workshop. This may provide a new twist to the idea
that life arrived from space. It may be that the precursors of life came
from space, but that the actual carbon based biochemistry of all
organisms on Earth evolved on this planet.

The workshop, Euroice2008 was held in Granada, Spain in October 2008

For more infomration please click here
<http://www.esf.org/activities/exploratory-workshops/workshops-list/workshops-detail.html?ew=6488>
Received on Fri 07 Nov 2008 05:35:26 PM PST