[meteorite-list] Power Behind Primordial Soup Discovered in Meteorite

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 5 Apr 2013 13:30:37 -0700 (PDT)
Message-ID: <201304052030.r35KUbbE002555_at_zagami.jpl.nasa.gov>

http://www.leeds.ac.uk/news/article/3386/power_behind_primordial_soup_discovered

Power behind primordial soup discovered
University of Leeds (United Kingdom)
4th April 13

Researchers at the University of Leeds may have solved a key puzzle
about how objects from space could have kindled life on Earth.

While it is generally accepted that some important ingredients for life
came from meteorites bombarding the early Earth, scientists have not
been able to explain how that inanimate rock transformed into the
building blocks of life.

This new study shows how a chemical, similar to one now found in all
living cells and vital for generating the energy that makes something
alive, could have been created when meteorites containing phosphorus
minerals landed in hot, acidic pools of liquids around volcanoes, which
were likely to have been common across the early Earth.

"The mystery of how living organisms sprung out of lifeless rock has
long puzzled scientists, but we think that the unusual phosphorus
chemicals we found could be a precursor to the batteries that now power
all life on Earth. But the fact that it developed simply, in conditions
similar to the early Earth, suggests this could be the missing link
between geology and biology," said Dr Terry Kee, from the University's
School of Chemistry, who led the research.

All life on Earth is powered by a process called chemiosmosis, where the
chemical adenosine triphosphate (ATP), the rechargeable chemical
"battery" for life, is both broken down and re-formed during respiration
to release energy used to drive the reactions of life, or metabolism.
The complex enzymes required for both the creation and break down of ATP
are unlikely to have existed on the Earth during the period when life
first developed. This led scientists to look for a more basic chemical
with similar properties to ATP, but that does not require enzymes to
transfer energy.

Phosphorus is the key element in ATP, and other fundamental building
blocks of life like DNA, but the form it commonly takes on Earth,
phosphorus (V), is largely insoluble in water and has a low chemical
reactivity. The early Earth, however, was regularly bombarded by
meteorites and interstellar dust rich in exotic minerals, including the
far more reactive form of phosphorus, the iron-nickel-phosphorus mineral
schreibersite.

The scientists simulated the impact of such a meteorite with the hot,
volcanically-active, early Earth by placing samples of the Sikhote-Alin
meteorite, an iron meteorite which fell in Siberia in 1947, in acid
taken from the Hveradalur geothermal area in Iceland. The rock was left
to react with the acidic fluid in test tubes incubated by the
surrounding hot spring for four days, followed by a further 30 days at
room temperature.

In their analysis of the resulting solution the scientists found the
compound pyrophosphite, a molecular "cousin" of pyrophosphate - the part
of ATP responsible for energy transfer. The scientists believe this
compound could have acted as an earlier form of ATP in what they have
dubbed "chemical life".

"Chemical life would have been the intermediary step between inorganic
rock and the very first living biological cell. You could think of
chemical life as a machine - a robot, for example, is capable of moving
and reacting to surroundings, but it is not alive. With the aid of these
primitive batteries, chemicals became organised in such a way as to be
capable of more complex behaviour and would have eventually developed
into the living biological structures we see today," said Dr Terry Kee.

The team from NASA's Jet Propulsion Laboratory (JPL-Caltech) working on
the Curiosity rover, which landed on Mars in August last year, has
recently reported the presence of phosphorus on the Red Planet.

"If Curiosity has found phosphorus in one of the forms we produced in
Iceland, this may indicate that conditions on Mars were at one point
suitable for the development of life in much the same way we now believe
it developed on Earth," added Dr Kee.

The team at Leeds are now working with colleagues at JPL-Caltech to
understand how these early batteries and the "chemical life" they became
part of might have developed into biological life. As part of this work
they will be using facilities in the University of Leeds' Faculty of
Engineering, currently used to test new fuel cells, to build a
"geological fuel cell" using minerals and gases common on the early
Earth. Researchers will apply different chemicals to its surface and
monitor the reactions take place and the chemical products which develop.

The team also hope to travel to Disko Island in Greenland which is home
to the Earth's only naturally-occurring source of schreibersite, the
mineral found in the Sikhote-Alin meteorite. Here, they hope to repeat
their experiments and show that the same chemicals develop in an
entirely Earth-originated setting.

The paper Hydrothermal modification of the Sikhote-Alin iron meteorite
under low pH geothermal environments. A plausibly prebiotic route to
activated phosphorus on the early Earth was published online by the
journal Geochimica et Cosmochimica Acta on 15th March 2013.

The research was funded by the Engineering and Physical Sciences
Research Council, Leverhulme Trust, Science and Technology Facilities
Council and the UK Space Agency.

For more information

Dr Terry Kee is available for interview.

Contact Richard Mellor, Communications, University of Leeds
T: +44 (0)113 3434031
E: r.d.mellor at leeds.ac.uk <mailto:r.d.mellor at leeds.ac.uk>

David E. Bryant, David Greenfield, Richard D. Walshaw, Benjamin R.G.
Johnson, Barry Herschy, Caroline Smith, Matthew A. Pasek, Richard
Telford, Ian Scowen, Tasnim Munshi, Howell G.M. Edwards, Claire R.
Cousins, Ian A. Crawford, Terence P. Kee, Hydrothermal modification of
the Sikhote-Alin iron meteorite under low pH geothermal environments. A
plausibly prebiotic route to activated phosphorus on the early Earth,
Geochimica et Cosmochimica Acta, Volume 109, 15 May 2013, Pages 90-112,
ISSN 0016-7037, 10.1016/j.gca.2012.12.043.
(http://www.sciencedirect.com/science/article/pii/S0016703713000161)
Received on Fri 05 Apr 2013 04:30:37 PM PDT