Web address:
http://www.sciencedaily.com/releases/2013/01/
130120145825.htm
Mars May Have Supported Life: Martian Underground Could Contain Clues to Life's
Origins
This view of layered rocks on the floor of McLaughlin Crater shows sedimentary
rocks that contain spectroscopic evidence for minerals formed through
interaction with water. (Credit: NASA/JPL-Caltech/Univ. of Arizona)
Jan. 20, 2013 Minerals found in the subsurface of Mars, a zone of more than
three miles below ground, make for the strongest evidence yet that the red
planet may have supported life, according to research "Groundwater activity on
Mars and implications for a deep biosphere," published in Nature Geoscience on
January 20, 2013.
Up to half of all life on Earth consists of simple microorganisms hidden in
rocks beneath the surface and for some time, scientists have suggested that the
same may be true for Mars. Now this theory has been supported by new research,
which suggests that the ingredients for life have been present in the Martian
subsurface for much of the planet's history.
When meteorites strike the surface of Mars, they act like natural probes,
bringing up rocks from far beneath the surface. Recent research has shown that
many of the rocks brought up from the Martian subsurface contain clays and
minerals whose chemical make-up has been altered by water, an essential element
to support life. Some deep craters on Mars also acted as basins where
groundwater likely emerged to produce lakes.
McLaughlin Crater, described in this study, is one such basin that contains
clay and carbonate minerals formed in an ancient lake on Mars. The fluids that
formed these minerals could carry clues to as to whether the subsurface
contained life.
"We don't know how life on Earth formed but it is conceivable that it
originated underground, protected from harsh surface conditions that existed on
early Earth. Due to plate tectonics, however, the early geological record of
Earth is poorly preserved so we may never know what processes led to life's
origin and early evolution," said Dr Joseph Michalski, lead author and
planetary geologist at the Natural History Museum in London. "Exploring these
rocks on Mars, where the ancient geologic record is better preserved than on
Earth, would be like finding a stack of pages that have been ripped out of
Earth's geological history book. Whether the Martian geologic record contains
life or not, analysis of these types of rocks would certainly teach us a
tremendous amount about early chemical processes in the solar system."
Co-author Deanne Rogers, Assistant Professor in the Department of Geosciences
at Stony Brook University used data from the Thermal Emission Spectrometer
aboard NASA's Mars Global Surveyor and the Thermal Emission Imaging System
aboard the Mars Odyssey orbiter to detect and identify minerals that proved to
be consistent with a sustained aqueous environment on the floor of the
McLaughlin Crater.
"Our understanding of Mars is changing very rapidly with all of the new mission
data," said Professor Rogers. "There have been several recent observations and
models that have pointed to the possibility of a vast store of groundwater in
the Martian past, and perhaps present. So you might expect that deep basins
such as McLaughlin, which intersect the upwelling groundwater table, would
contain evidence of this water. And this study found that evidence."
Current exploration of Mars focuses on investigating surface processes because
sedimentary rocks are most likely to provide the best chance evidence for
habitability. Evidence suggests, however, that the Martian surface environment
has been quite inhospitable to life for billions of years. In future missions,
scientists could choose to target rocks related to the surface or subsurface,
or perhaps do both by targeting areas where sedimentary rocks formed from
subsurface fluids.
Michalski concludes: 'In this paper, we present a strong case for exploring the
subsurface, as well as the surface. But I don't personally think we should try
to drill into the subsurface to look for ancient life. Instead, we can study
rocks that are naturally brought to the surface by meteor impact and search in
deep basins where fluids have come to the surface.'
Co-author Professor John Parnell, geochemist at the University of Aberdeen,
commented, "This research has demonstrated how studies of Earth and Mars depend
on each other. It is what we have observed of microbes living below the
continents and oceans of Earth. They allow us to speculate on habitats for past
life on Mars, which in turn show us how life on the early Earth could have
survived. We know from Earth's history that planets face traumatic conditions
such as meteorite bombardment and ice ages, when the survival of life may
depend on being well below ground. So it makes sense to search for evidence of
life from that subsurface environment, in the geological records of both Earth
and Mars. But it's one thing to do that on Earth -- we need to be clever in
finding a way to do it on Mars."
Additional co-authors of the study include: Javier Caudros, Researcher, Clay
Mineralogy, Earth Sciences Department, Natural History Museum, London; Paul B.
Niles, Planetary Scientist, NASA Johnson Space Center; and Shawn P. Wright,
Postdoctoral Fellow in Geology, Auburn University.
Share this story on Facebook, Twitter, and Google:
Other social bookmarking and sharing tools:
Share on reddit Share on stumbleupon Share on pinterest_share Share on blogger
Share on digg Share on fark Share on linkedin Share on myspace Share on
newsvine | 68
Story Source:
The above story is reprinted from materials provided by Stony Brook
University.
Note: Materials may be edited for content and length. For further
information, please contact the source cited above.
Journal Reference:
Joseph R. Michalski, Javier Cuadros, Paul B. Niles, John Parnell, A. Deanne
Rogers, Shawn P. Wright. Groundwater activity on Mars and implications for a
deep biosphere. Nature Geoscience, 2013; DOI: 10.1038/ngeo1706
Need to cite this story in your essay, paper, or report? Use one of the
following formats:
APA
MLA
Stony Brook University (2013, January 20). Mars may have supported life:
Martian underground could contain clues to life's origins. ScienceDaily.
Retrieved January 22, 2013, from http://www.sciencedaily.com
/releases/2013/01/130120145825.htm
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of
ScienceDaily or its staff.
------------------------------------
Post message: [email protected]
Subscribe : [email protected]
Unsubscribe : [email protected]
List owner : [email protected]
Homepage : http://proletar.8m.com/Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/proletar/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/proletar/join
(Yahoo! ID required)
<*> To change settings via email:
[email protected]
[email protected]
<*> To unsubscribe from this group, send an email to:
[email protected]
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
