Life Elsewhere in Solar System Could Be Different From Life as WeKnow It (Forwarded)

What about optical activity! Terrestrial life tends to be dextro
rotary. My experiment would be to send a laser to Europa.


- Ian Parker

Office of News and Public Information
National Academies

Contacts:
Paul Jackson
Michelle Strikowsky
Office of News and Public Information
202-334-2138

FOR IMMEDIATE RELEASE: July 6, 2007

Life Elsewhere in Solar System Could Be Different From Life as We Know It

WASHINGTON -- The search for life elsewhere in the solar system and beyond
should include efforts to detect what scientists sometimes refer to as
"weird" life -- that is, life with an alternative biochemistry to that of
life on Earth -- says a new report from the National Research Council.
The committee that wrote the report found that the fundamental
requirements for life as we generally know it -- a liquid water
biosolvent, carbon-based metabolism, molecular system capable of
evolution, and the ability to exchange energy with the environment -- are
not the only ways to support phenomena recognized as life. "Our
investigation made clear that life is possible in forms different than
those on Earth," said committee chair John Baross, professor of
oceanography at the University of Washington, Seattle.

The report emphasizes that "no discovery that we can make in our
exploration of the solar system would have greater impact on our view of
our position in the cosmos, or be more inspiring, than the discovery of an
alien life form, even a primitive one. At the same time, it is clear that
nothing would be more tragic in the American exploration of space than to
encounter alien life without recognizing it."

The tacit assumption that alien life would utilize the same biochemical
architecture as life on Earth does means that scientists have artificially
limited the scope of their thinking as to where extraterrestrial life
might be found, the report says. The assumption that life requires water,
for example, has limited thinking about likely habitats on Mars to those
places where liquid water is thought to be present or have once flowed,
such as the deep subsurface. However, according to the committee, liquids
such as ammonia or formamide could also work as biosolvents -- liquids
that dissolve substances within an organism -- albeit through a different
biochemistry. The recent evidence that liquid water-ammonia mixtures may
exist in the interior of Saturn's moon Titan suggests that increased
priority be given to a follow-on mission to probe Titan, a locale the
committee considers the solar system's most likely home for weird life.

"It is critical to know what to look for in the search for life in the
solar system," said Baross. "The search so far has focused on Earth-like
life because that's all we know, but life that may have originated
elsewhere could be unrecognizable compared with life here. Advances
throughout the last decade in biology and biochemistry show that the basic
requirements for life might not be as concrete as we thought."

Besides the possibility of alternative biosolvents, studies show that
variations on some of the other basic tenets for life also might be able
to support weird life. DNA on Earth works through the pairing of four
chemical compounds called nucleotides, but experiments in synthetic
biology have created structures with six or more nucleotides that can also
encode genetic information and, potentially, support Darwinian evolution.
Additionally, studies in chemistry show that an organism could utilize
energy from alternative sources, such as through a reaction of sodium
hydroxide and hydrochloric acid, meaning that such an organism could have
an entirely non-carbon-based metabolism.

Researchers need to further explore variations of the requirements for
life with particular emphasis on origin-of-life studies, which will help
determine if life can exist without water or in environments where water
is only present under extreme conditions, the report says. Most planets
and moons in this solar system fall into one of these categories.
Research should also focus on how organisms break down key elements, as
even non-carbon-based life would need elements for energy, structure, and
chemical reactions.

The report also stresses that the future search for alien life should not
exclude additional research into terrestrial life. Through examination of
extreme environments, such as deserts and deep under the oceans, studies
have determined that life exists essentially anywhere water and a source
of energy are found together on Earth. Field researchers should therefore
seek out organisms with novel biochemistries and those that exist in areas
where vital resources are scarce to better understand how life on Earth
truly operates, the committee said. This improved understanding will
contribute greatly toward seeking Earth-like life where the conditions
necessary for its existence might be met, as in the case of subsurface
Mars.

Space missions will need adjustment to increase the breadth of their
search for life. Planned Mars missions, for example, should include
instruments that detect components of light elements -- especially carbon,
hydrogen, oxygen, phosphorous, and sulfur -- as well as simple organic
functional groups and organic carbon. Recent evidence indicates that
another moon of Saturn, Enceladus, has active water geysers, raising the
prospect that habitable environments may exist there and greatly
increasing the priority of additional studies of this body.

NASA sponsored the report. The National Academy of Sciences, National
Academy of Engineering, Institute of Medicine, and National Research
Council make up the National Academies. They are private, nonprofit
institutions that provide science, technology, and health policy advice
under a congressional charter. The Research Council is the principal
operating agency of the National Academy of Sciences and the National
Academy of Engineering. A committee roster follows.

Copies of "The Limits of Organic Life in Planetary Systems" will be
available from the National Academies Press; tel. 202-334-3313 or
1-800-624-6242 or on the Internet at http://www.nap.edu . The cost of the
report is $27.50 (prepaid) plus shipping charges of $4.50 for the first
copy and $.95 for each additional copy. Reporters may obtain a
pre-publication copy from the Office of News and Public Information
(contacts listed above).

Read Full Report:
http://www.nap.edu/catalog/11919.html


NATIONAL RESEARCH COUNCIL

Division on Engineering and Physical Sciences
Space Studies Board
Committee on the Limits of Organic Life in Planetary Systems

John A. Baross (chair)
Professor of Biological Oceanography
University of Washington
Seattle

Steven A. Benner
Distinguished Fellow
Foundation for Applied Molecular Evolution
Gainesville, Fla.

George D. Cody
Geologist and Member of Senior Research Staff
Geophysical Laboratory
Carnegie Institution of Washington
Washington, D.C.

Shelley D. Copley
Professor
Department of Molecular, Cellular, and Developmental Biology
University of Colorado
Boulder

Norman R. Pace[*]
Professor
Department of Molecular, Cellular, and Developmental Biology
University of Colorado
Boulder

James H. Scott
Leader of the Geobiology Group
Department of Earth Sciences
Dartmouth College
Hanover, N.H.

Robert Shapiro
Professor Emeritus and Senior Research Scientist
Department of Chemistry
New York University
New York City

Mitchell L. Sogin
Director
Bay Paul Center for Comparative Molecular Biology and Evolution
Marine Biological Laboratory
Woods Hole, Mass.

Jeffrey L. Stein
Kauffman Fellow
Sofinnova Ventures
San Francisco

Roger Summons
Professor
Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology
Cambridge

Jack W. Szostak[*]
Alexander Rich Distinguished Investigator
Massachusetts General Hospital, and
Professor of Genetics
Harvard Medical School
Boston

RESEARCH COUNCIL STAFF

David H. Smith
Study Director
[*] Member, National Academy of Sciences

Yes I am completely different from. Totally, I am flesh and blood but not
your flesh and blood and feel four arms is better than two and talons are
better than hands and I can hang upside down from tree branch to pick choice
borrowing worms of trees and pick fruits to pick up with my trunk to put in
my mouth, but you'll get used to it as my friends do.


"Ian Parker" wrote in message
oups.com...
What about optical activity! Terrestrial life tends to be dextro
rotary. My experiment would be to send a laser to Europa.


- Ian Parker

On 11 Jul, 06:19, "Zomp" wrote:
Yes I am completely different from. Totally, I am flesh and blood but not
your flesh and blood and feel four arms is better than two and talons are
better than hands and I can hang upside down from tree branch to pick choice
borrowing worms of trees and pick fruits to pick up with my trunk to put in
my mouth, but you'll get used to it as my friends do.

"Ian Parker" wrote in message

oups.com...



What about optical activity! Terrestrial life tends to be dextro
rotary. My experiment would be to send a laser to Europa.

The more usual picture is of a colony on Europa round a volcanic vent.


- Ian Parker