New Analysis of Viking Mission Results Indicates Presence of Lifeon Mars (Forwarded)

News Service
Washington State University
Pullman, Washington

Contact:
Dirk Schulze-Makuch, WSU School of Earth and Environmental Sciences
509/335-1180

Cherie Winner, WSU News Service
509/335-4846

1/5/2007

NEW ANALYSIS OF VIKING MISSION RESULTS POINTS TO THE PRESENCE OF LIFE ON
MARS

PULLMAN, Wash. -- We may already have 'met' Martian organisms, according
to a paper presented Sunday (Jan. 7) at the meeting of the American
Astronomical Society in Seattle.

Dirk Schulze-Makuch of Washington State University and Joop Houtkooper of
Justus-Liebig-University, Giessen, Germany, argue that even as new
missions to Mars seek evidence that the planet might once have supported
life, we already have data showing that life exists there now -- data from
experiments done by the Viking Mars landers in the late 1970s.

"I think the Viking results have been a little bit neglected in the last
10 years or more," said Schulze-Makuch. "But actually, we got a lot of
data there." He said recent findings about Earth organisms that live in
extreme environments and improvements in our understanding of conditions
on Mars give astrobiologists new ways of looking at the 30-year-old data.

The researchers hypothesize that Mars is home to microbe-like organisms
that use a mixture of water and hydrogen peroxide as their internal fluid.
Such a mixture would provide at least three clear benefits to organisms in
the cold, dry Martian environment, said Schulze-Makuch. Its freezing point
is as low as -56.5 C (depending on the concentration of H2O2); below that
temperature it becomes firm but does not form cell-destroying crystals, as
water ice does; and H2O2 is hygroscopic, which means it attracts water
vapor from the atmosphere -- a valuable trait on a planet where liquid
water is rare.

Schulze-Makuch said that despite hydrogen peroxide's reputation as a
powerful disinfectant, the fluid is also compatible with biological
processes if it is accompanied by stabilizing compounds that protect cells
from its harmful effects. It performs useful functions inside cells of
many terrestrial organisms, including mammals. Some soil microbes tolerate
high levels of H2O2 in their surroundings, and the species Acetobacter
peroxidans uses hydrogen peroxide in its metabolism.

Possibly the most vivid use of hydrogen peroxide by an Earth organism is
performed by the bombardier beetle (Brachinus), which produces a solution
of 25 percent hydrogen peroxide in water as a defensive spray. The noxious
liquid shoots from a special chamber at the beetle's rear end when the
beetle is threatened.

He said scientists working on the Viking projects weren't looking for
organisms that rely on hydrogen peroxide, because at the time nobody was
aware that such organisms could exist. The study of extremophiles,
organisms that thrive in conditions of extreme temperatures or chemical
environments, has just taken off since the 90s, well after the Viking
experiments were conducted.

The researchers argue that hydrogen peroxide-containing organisms could
have produced almost all of the results observed in the Viking
experiments.

* Hydrogen peroxide is a powerful oxidant. When released from dying cells,
it would sharply lower the amount of organic material in their
surroundings. This would help explain why Viking's gas chromatograph-mass
spectrometer detected no organic compounds on the surface of Mars. This
result has also been questioned recently by Rafael Navarro-Gonzalez of the
University of Mexico, who reported that similar instruments and
methodology are unable to detect organic compounds in places on Earth,
such as Antarctic dry valleys, where we know soil microorganisms exist.

* The Labeled Release experiment, in which samples of Martian soil (and
putative soil organisms) were exposed to water and a nutrient source
including radiolabeled carbon, showed rapid production of radiolabeled CO2
which then leveled off. Schulze-Makuch said the initial increase could
have been due to metabolism by hydrogen peroxide-containing organisms, and
the leveling off could have been due to the organisms dying from exposure
to the experimental conditions. He said that point has been argued for
years by Gilbert Levin, who was a primary investigator on the original
Viking team. The new hypothesis explains why the experimental conditions
would have been fatal: microbes using a water-hydrogen peroxide mixture
would either "drown" or burst due to water absorption, if suddenly exposed
to liquid water.

* The possibility that the tests killed the organisms they were looking
for is also consistent with the results of the Pyrolytic Release
experiment, in which radiolabeled CO2 was converted to organic compounds
by samples of Martian soil. Of the seven tests done, three showed
significant production of organic substances and one showed much higher
production. The variation could simply be due to patchy distribution of
microbes, said Schulze-Makuch. Perhaps most interesting was that the
sample with the lowest production -- lower even than the control -- had
been treated with liquid water.

The researchers acknowledge that their hypothesis requires further
exploration. "We can be absolutely wrong, and there might not be organisms
like that at all," said Schulze-Makuch. "But it's a consistent explanation
that would explain the Viking results."

He said the Phoenix mission to Mars, which is scheduled for launch in
August, 2007, offers a good chance to further explore their hypothesis.
Although the mission's experiments were not designed with
peroxide-containing organisms in mind, Phoenix will land in a sub-polar
area, whose low temperatures and relatively high atmospheric water vapor
(from the nearby polar ice caps) should provide better growing conditions
for such microbes than the more "tropical" region visited by Viking.
Schulze-Makuch said the tests planned for the mission, including the use
of two microscopes to examine samples at high magnification, could reveal
whether we had the answer all along -- and if we've already introduced
ourselves to our Martian neighbors in a harsher way than we intended.

"If the hypothesis is true, it would mean that we killed the Martian
microbes during our first extraterrestrial contact, by drowning -- due to
ignorance," said Schulze-Makuch.

The oxygen released during the viking experiments did indicate the break
down of peroxides with the addition of water, high rate first then slowing
down.
"Andrew Yee" wrote in message
...
News Service
Washington State University
Pullman, Washington

Contact:
Dirk Schulze-Makuch, WSU School of Earth and Environmental Sciences
509/335-1180

Cherie Winner, WSU News Service
509/335-4846

1/5/2007

NEW ANALYSIS OF VIKING MISSION RESULTS POINTS TO THE PRESENCE OF LIFE ON
MARS

PULLMAN, Wash. -- We may already have 'met' Martian organisms, according
to a paper presented Sunday (Jan. 7) at the meeting of the American
Astronomical Society in Seattle.

Dirk Schulze-Makuch of Washington State University and Joop Houtkooper of
Justus-Liebig-University, Giessen, Germany, argue that even as new
missions to Mars seek evidence that the planet might once have supported
life, we already have data showing that life exists there now -- data from
experiments done by the Viking Mars landers in the late 1970s.

"I think the Viking results have been a little bit neglected in the last
10 years or more," said Schulze-Makuch. "But actually, we got a lot of
data there." He said recent findings about Earth organisms that live in
extreme environments and improvements in our understanding of conditions
on Mars give astrobiologists new ways of looking at the 30-year-old data.

The researchers hypothesize that Mars is home to microbe-like organisms
that use a mixture of water and hydrogen peroxide as their internal fluid.
Such a mixture would provide at least three clear benefits to organisms in
the cold, dry Martian environment, said Schulze-Makuch. Its freezing point
is as low as -56.5 C (depending on the concentration of H2O2); below that
temperature it becomes firm but does not form cell-destroying crystals, as
water ice does; and H2O2 is hygroscopic, which means it attracts water
vapor from the atmosphere -- a valuable trait on a planet where liquid
water is rare.

Schulze-Makuch said that despite hydrogen peroxide's reputation as a
powerful disinfectant, the fluid is also compatible with biological
processes if it is accompanied by stabilizing compounds that protect cells
from its harmful effects. It performs useful functions inside cells of
many terrestrial organisms, including mammals. Some soil microbes tolerate
high levels of H2O2 in their surroundings, and the species Acetobacter
peroxidans uses hydrogen peroxide in its metabolism.

Possibly the most vivid use of hydrogen peroxide by an Earth organism is
performed by the bombardier beetle (Brachinus), which produces a solution
of 25 percent hydrogen peroxide in water as a defensive spray. The noxious
liquid shoots from a special chamber at the beetle's rear end when the
beetle is threatened.

He said scientists working on the Viking projects weren't looking for
organisms that rely on hydrogen peroxide, because at the time nobody was
aware that such organisms could exist. The study of extremophiles,
organisms that thrive in conditions of extreme temperatures or chemical
environments, has just taken off since the 90s, well after the Viking
experiments were conducted.

The researchers argue that hydrogen peroxide-containing organisms could
have produced almost all of the results observed in the Viking
experiments.

* Hydrogen peroxide is a powerful oxidant. When released from dying cells,
it would sharply lower the amount of organic material in their
surroundings. This would help explain why Viking's gas chromatograph-mass
spectrometer detected no organic compounds on the surface of Mars. This
result has also been questioned recently by Rafael Navarro-Gonzalez of the
University of Mexico, who reported that similar instruments and
methodology are unable to detect organic compounds in places on Earth,
such as Antarctic dry valleys, where we know soil microorganisms exist.

* The Labeled Release experiment, in which samples of Martian soil (and
putative soil organisms) were exposed to water and a nutrient source
including radiolabeled carbon, showed rapid production of radiolabeled CO2
which then leveled off. Schulze-Makuch said the initial increase could
have been due to metabolism by hydrogen peroxide-containing organisms, and
the leveling off could have been due to the organisms dying from exposure
to the experimental conditions. He said that point has been argued for
years by Gilbert Levin, who was a primary investigator on the original
Viking team. The new hypothesis explains why the experimental conditions
would have been fatal: microbes using a water-hydrogen peroxide mixture
would either "drown" or burst due to water absorption, if suddenly exposed
to liquid water.

* The possibility that the tests killed the organisms they were looking
for is also consistent with the results of the Pyrolytic Release
experiment, in which radiolabeled CO2 was converted to organic compounds
by samples of Martian soil. Of the seven tests done, three showed
significant production of organic substances and one showed much higher
production. The variation could simply be due to patchy distribution of
microbes, said Schulze-Makuch. Perhaps most interesting was that the
sample with the lowest production -- lower even than the control -- had
been treated with liquid water.

The researchers acknowledge that their hypothesis requires further
exploration. "We can be absolutely wrong, and there might not be organisms
like that at all," said Schulze-Makuch. "But it's a consistent explanation
that would explain the Viking results."

He said the Phoenix mission to Mars, which is scheduled for launch in
August, 2007, offers a good chance to further explore their hypothesis.
Although the mission's experiments were not designed with
peroxide-containing organisms in mind, Phoenix will land in a sub-polar
area, whose low temperatures and relatively high atmospheric water vapor
(from the nearby polar ice caps) should provide better growing conditions
for such microbes than the more "tropical" region visited by Viking.
Schulze-Makuch said the tests planned for the mission, including the use
of two microscopes to examine samples at high magnification, could reveal
whether we had the answer all along -- and if we've already introduced
ourselves to our Martian neighbors in a harsher way than we intended.

"If the hypothesis is true, it would mean that we killed the Martian
microbes during our first extraterrestrial contact, by drowning -- due to
ignorance," said Schulze-Makuch.