[meteorite-list] Water and Methane Maps Overlap on Mars: A New Clue?

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Sep 20 12:14:03 2004
Message-ID: <200409201613.JAA05547_at_zagami.jpl.nasa.gov>

http://www.esa.int/export/SPECIALS/Mars_Express/SEML131XDYD_0.html

Water and methane maps overlap on Mars: a new clue?
European Space Agency
20 September 2004

ESA PR 51-2004. Recent analyses of ESA's Mars Express data reveal that
concentrations of water vapour and methane in the atmosphere of Mars
significantly overlap. This result, from data obtained by the Planetary
Fourier Spectrometer (PFS), gives a boost to understanding of geological
and atmospheric processes on Mars, and provides important new hints to
evaluate the hypothesis of present life on the Red Planet.

PFS observed that, at 10-15 kilometres above the surface, water vapour
is well mixed and uniform in the atmosphere. However, it found that,
close to the surface, water vapour is more concentrated in three broad
equatorial regions: Arabia Terra, Elysium Planum and Arcadia-Memnonia.

Here, the concentration is two to three times higher than in other
regions observed. These areas of water vapour concentration also
correspond to the areas where NASA's Odyssey spacecraft has observed a
water ice layer a few tens of centimetres below the surface, as Dr
Vittorio Formisano, PFS principal investigator, reports.

New in-depth analysis of PFS data also confirms that methane is not
uniform in the atmosphere, but concentrated in some areas. The PFS team
observed that the areas of highest concentration of methane overlap with
the areas where water vapour and underground water ice are also
concentrated. This spatial correlation between water vapour and methane
seems to point to a common underground source.

Initial speculation has taken the underground ice layer into account.
This could be explained by the "ice table" concept, in which geothermal
heat from below the surface makes water and other material move towards
the surface. It would then freeze before getting there, due to the very
low surface temperature (many tens of degrees Celsius below zero).

Further investigations are needed to fully understand the correlation
between the ice table and the presence and distribution of water vapour
and methane in the atmosphere.

In other words, can the geothermal processes which "feed" the ice table
also bring water vapour and other gases, like methane, to the surface?
Can there be liquid water below the ice table? Can forms of bacterial
life exist in the water below the ice table, producing methane and other
gases and releasing them to the surface and then to the atmosphere?

The PFS instrument has also detected traces of other gases in the
Martian atmosphere. A report on these is currently under peer review.
Further studies will address whether these gases can be linked to water
and methane and help answer the unresolved questions. In-situ
observations by future lander missions to Mars may provide a more
exhaustive solution to the puzzle.

Note to editors

The result is reported today, 20 September, by Dr Vittorio Formisano at
the International Mars Conference (19-23 September), organised by the
Italian Space Agency (ASI) in Ischia, Italy.

The objective of the PFS instrument is the study, with unprecedented
spectral resolution, of temperature fields in the atmosphere, dust,
variation and cycle of water and carbon monoxide, vertical distribution
of water, soil-atmosphere interactions and minor gaseous species. From
this, hints of extant life can be extracted (in terms of the presence of
"biomarker" gases and chemical study of atmospheric environmental
conditions).

The PFS is an Italian Space Agency instrument, developed by the Istituto
di Fisica dello Spazio Interplanetario (IFSI) of the Istituto Nazionale
di Astrofisica (INAF), in the framework of ESA's Mars Express mission.

 
 
For more information please contact:
 
ESA Media Relations Division
Tel: +33(0)1.53.69.7155
Fax: +33(0)1.53.69.7690

Vittorio Formisano, Mars Express PFS Principal Investigator
IFSI-CNR, Rome, Italy
Tel : +39 06 4993 4362
Email: formisan_at_ifsi.rm.cnr.it

 
Received on Mon 20 Sep 2004 12:13:57 PM PDT