Andrew Yee
October 18th 04, 06:46 PM
University Relations
Virginia Tech
CONTACT:
Sally Harris, (540)231-6759,
October 14, 2004
Virginia Tech researchers suggest liquid water may have existed on Mars;
findings published in Nature
By Sally Harris
Blacksburg, Va. -- A Ph.D. student at Virginia Tech has research published this
week in Nature that shows Mars probably had liquid water at some point, but
likely for only a short time, geologically speaking.
Megan Elwood Madden, of Jacksonville, Ill., a graduate student in geosciences in
the College of Science, along with Robert Bodnar, University Distinguished
Professor and Clifton C. Garvin Professor of Geosciences, and Donald Rimstidt,
professor of geosciences, both in the College of Science, published "Jarosite as
an indicator of water-limited chemical weathering on Mars" in the Oct. 14 issue
of Nature according to a press release from Nature.
NASA's Mars Rover Opportunity recently found the mineral jarosite and possibly
gypsum on Mars' surface, further adding to the speculation that water existed
there in the past because those minerals "generally form in a wet environment,"
according to a Nature news release.
It was already well known from previous Mars research and meteorites that basalt
is likely a common rock type on Mars, Elwood Madden said. Scientists are
interested in the history of water on Mars since life as we know it cannot
survive without liquid water. Ice can be found on Mars today; however, liquid
water likely froze or evaporated some time in the past.
Using a computer-modeling program that uses thermodynamic data to determine the
types of minerals that form from reactions between rocks and water, Elwood
Madden looked at the way basalts weather, or react with water, under the
conditions found on Mars and used the results to interpret how jarosite and
gypsum might have formed. "We predicted jarosite likely did form from a reaction
of basalt with liquid water," Madden said.
According to the press release from Nature, "On Earth, jarosite forms in acid
mine drainage environments as sulphide minerals oxidize -- it has been found in
Idaho or California, for example. It also forms while volcanic rocks are being
altered by acidic, sulphur-rich fluids near volcanic vents. As such, jarosite
formation is thought to need a wet, oxidizing and acidic environment."
However, it is preserved only in arid regions. The reason, Elwood Madden and
Rimstidt said, is that jarosite forms when only a small amount of reaction has
occurred and completely decomposes if more water is available. "This shows that
the reaction on Mars ran out of water," Elwood Madden said.
"Either there was not enough water to begin with or it disappeared quickly,"
Rimstidt said.
Elwood Madden, Bodnar, and Rimstidt showed "that the water in which the minerals
formed either evaporated or soaked into the ground after a short time,"
according to Nature.
Because water is important for life, the discovery could have implications of
how long water was present on Mars and the likelihood of finding living
organisms there now. "There's probably no likelihood of living organisms today,
but we can't say there wasn't enough water a long time ago," Rimstidt said.
As to how much water was on Mars, the researchers do not know if there was a
great deal for a short time or a little for a longer period. However, they can
say there was a geologically short window in which liquid water was present,
suggesting there also was a limited time period when conditions may have been
hospitable for life, Rimstidt said.
The researchers will present the results of their work in November at the
Geological Society of America meeting in Denver.
The College of Science at Virginia Tech gives students a comprehensive
foundation in the scientific method. Outstanding faculty members teach courses
and conduct research in biology, chemistry, economics, geosciences, mathematics,
physics, psychology, and statistics. The college is dedicated to fostering a
research intensive environment and offers programs in nano-scale and biological
sciences, information theory and science, and supports research centers -- in
areas such as biomedical and public health sciences, and critical technology and
applied science -- that encompass other colleges at the university. The College
of Science also houses programs in pre-medicine and scientific law.
Founded in 1872 as a land-grant college, Virginia Tech has grown to become among
the largest universities in the Commonwealth of Virginia. Today, Virginia Tech's
eight colleges are dedicated to putting knowledge to work through teaching,
research, and outreach activities and to fulfilling its vision to be among the
top research universities in the nation. At its 2,600-acre main campus located
in Blacksburg and other campus centers in Northern Virginia, Southwest Virginia,
Hampton Roads, Richmond, and Roanoke, Virginia Tech enrolls more than 28,000
full- and part-time undergraduate and graduate students from all 50 states and
more than 100 countries in 180 academic degree programs.
##04508##
Megan Elwood Madden can be reached at (540) 250-5833 or . Dr.
Donald Rimstidt can be reached at (550) 392-8913 or . Robert Bodnar
can be reached after Wednesday at (540) 231-7455 or .
Virginia Tech
CONTACT:
Sally Harris, (540)231-6759,
October 14, 2004
Virginia Tech researchers suggest liquid water may have existed on Mars;
findings published in Nature
By Sally Harris
Blacksburg, Va. -- A Ph.D. student at Virginia Tech has research published this
week in Nature that shows Mars probably had liquid water at some point, but
likely for only a short time, geologically speaking.
Megan Elwood Madden, of Jacksonville, Ill., a graduate student in geosciences in
the College of Science, along with Robert Bodnar, University Distinguished
Professor and Clifton C. Garvin Professor of Geosciences, and Donald Rimstidt,
professor of geosciences, both in the College of Science, published "Jarosite as
an indicator of water-limited chemical weathering on Mars" in the Oct. 14 issue
of Nature according to a press release from Nature.
NASA's Mars Rover Opportunity recently found the mineral jarosite and possibly
gypsum on Mars' surface, further adding to the speculation that water existed
there in the past because those minerals "generally form in a wet environment,"
according to a Nature news release.
It was already well known from previous Mars research and meteorites that basalt
is likely a common rock type on Mars, Elwood Madden said. Scientists are
interested in the history of water on Mars since life as we know it cannot
survive without liquid water. Ice can be found on Mars today; however, liquid
water likely froze or evaporated some time in the past.
Using a computer-modeling program that uses thermodynamic data to determine the
types of minerals that form from reactions between rocks and water, Elwood
Madden looked at the way basalts weather, or react with water, under the
conditions found on Mars and used the results to interpret how jarosite and
gypsum might have formed. "We predicted jarosite likely did form from a reaction
of basalt with liquid water," Madden said.
According to the press release from Nature, "On Earth, jarosite forms in acid
mine drainage environments as sulphide minerals oxidize -- it has been found in
Idaho or California, for example. It also forms while volcanic rocks are being
altered by acidic, sulphur-rich fluids near volcanic vents. As such, jarosite
formation is thought to need a wet, oxidizing and acidic environment."
However, it is preserved only in arid regions. The reason, Elwood Madden and
Rimstidt said, is that jarosite forms when only a small amount of reaction has
occurred and completely decomposes if more water is available. "This shows that
the reaction on Mars ran out of water," Elwood Madden said.
"Either there was not enough water to begin with or it disappeared quickly,"
Rimstidt said.
Elwood Madden, Bodnar, and Rimstidt showed "that the water in which the minerals
formed either evaporated or soaked into the ground after a short time,"
according to Nature.
Because water is important for life, the discovery could have implications of
how long water was present on Mars and the likelihood of finding living
organisms there now. "There's probably no likelihood of living organisms today,
but we can't say there wasn't enough water a long time ago," Rimstidt said.
As to how much water was on Mars, the researchers do not know if there was a
great deal for a short time or a little for a longer period. However, they can
say there was a geologically short window in which liquid water was present,
suggesting there also was a limited time period when conditions may have been
hospitable for life, Rimstidt said.
The researchers will present the results of their work in November at the
Geological Society of America meeting in Denver.
The College of Science at Virginia Tech gives students a comprehensive
foundation in the scientific method. Outstanding faculty members teach courses
and conduct research in biology, chemistry, economics, geosciences, mathematics,
physics, psychology, and statistics. The college is dedicated to fostering a
research intensive environment and offers programs in nano-scale and biological
sciences, information theory and science, and supports research centers -- in
areas such as biomedical and public health sciences, and critical technology and
applied science -- that encompass other colleges at the university. The College
of Science also houses programs in pre-medicine and scientific law.
Founded in 1872 as a land-grant college, Virginia Tech has grown to become among
the largest universities in the Commonwealth of Virginia. Today, Virginia Tech's
eight colleges are dedicated to putting knowledge to work through teaching,
research, and outreach activities and to fulfilling its vision to be among the
top research universities in the nation. At its 2,600-acre main campus located
in Blacksburg and other campus centers in Northern Virginia, Southwest Virginia,
Hampton Roads, Richmond, and Roanoke, Virginia Tech enrolls more than 28,000
full- and part-time undergraduate and graduate students from all 50 states and
more than 100 countries in 180 academic degree programs.
##04508##
Megan Elwood Madden can be reached at (540) 250-5833 or . Dr.
Donald Rimstidt can be reached at (550) 392-8913 or . Robert Bodnar
can be reached after Wednesday at (540) 231-7455 or .