Fwd: Mars at the EGS: new techniques for an old planet
tony...@myinternetuk.com
05 May 2000 16:25:45
sci.astro
From: ay...@nova.astro.utoronto.ca
Subject: Mars at the EGS: new techniques for an old planet (Forwarded)
To: sci.astro
ESA Science News
http://sci.esa.int
03 May 2000
Mars at the EGS: new techniques for an old planet
Where to land?
If you're going to send a lander to look for life on Mars, you need to
choose
a landing site with a good chance of harbouring life -- preferably a
place
where water once deposited layers of sediment. "But even with MOC data
(MOC
is the high resolution camera on board NASA's Mars Global Surveyor),
we
don't know exactly which kind of environment we're going to meet,"
Gian
Ori from the Universita d'Annunzio, Pescara, Italy told a session of
the
European Geophysical Society's millennium conference in Nice, France,
last
week (25-29 April 2000).
In collaboration with NASA's Ames Laboratory, he and a colleague are
working
on a proposal to send a reconnaissance mission to search for suitable
landing
sites. The Scout mission, consisting of a flotilla of tiny spacecraft,
would
reduce the risk of sending sophisticated and expensive landers to
relatively
uncharted territory. It was just one of several new ideas for future
Mars
exploration presented to the EGS General Assembly.
Scout would probably be too late to help Beagle 2, the lander on board
Mars
Express, with its choice of landing site: Beagle 2 will arrive at the
red
planet at the end of 2003. But Scout could be sent in advance of
future
landers, such as those under consideration by ESA for flight on the
flexible
mission MASTER, or on a future spacecraft in NASA's Mars Surveyor
series.
MASTER, a mission that would drop a lander on Mars en route to an
asteroid,
is progressing through the selection procedure for ESA's next flexible
missions, F2 and F3. The final selection will be made in September
2000.
To save costs, the lander would probably be a copy of Beagle 2 or one
of
the French space agency's (CNES) Netlanders.
The search for life
However, a team of scientists convened by ESA's Spaceflight and
Microgravity
Directorate has also drawn up plans for a more ambitious lander that
would
carry 35kg of instruments compared with 10kg on board Beagle 2. "Our
task
was to develop and design a package to optimise the search for life on
Mars," Andre Brack from the Centre de Biophysique Moléculaire, CNRS,
Orléans, France and chairman of the group told the conference.
The main aims of the package are to take microscope images of
underground
soil and rock samples and to measure the ratio of C12 to C13, which is
higher if life is or has been present. Many of these aims will be met
by
Beagle 2, which Brack described as "the most complete integrated
package
within such a small mass budget". The greater weight of instruments
allowed
on a future exobiology lander, however, gives it scope for more
sophisticated imaging, including Raman microscopy, and the possibility
of
drilling down to 1.5m for samples.
Because of its low weight, Beagle 2 cannot support a drill to take
deep core
samples from solid rock. Instead, it will use a "mole" to burrow down
through
soft soil or sediment and a grinder and small drill (supplied by a
dentist
in Hong Kong) to take samples from just below the weathered rind of
hard
rock. With the later exobiology lander "we hope to drill through the
oxidised layer and then core. But if we can't -- because it's
difficult to
core with robots -- then we'll take chips of rock," said Brack.
New ideas on geology and climate The meeting also heard of new ideas
for
learning more about the geology and climate history of Mars. The MEEM
proposal, for example, would build on experience gained with Marsis,
the
ground penetrating radar on board Mars Express, to mount a synthetic
aperture radar on board a future orbiter. P Paillou from the
Observatoire
Astronomique de Bordeaux, France, told the meeting that MEEM would
operate
at shorter wavelengths than Marsis and thus penetrate only a few tens
of
metres to reveal the shape of the Martian crust underneath obscuring
sand
and dust deposits. Marsis will penetrate a few kilometres underground
to
search for water.
Several participants at the meeting were looking forward to flying
gamma
ray spectrometers around Mars because they would reveal the elemental
composition of the surface. Omega, the infra red spectrometer that
will
fly on Mars Express, will reveal the mineral composition. Yet others
wanted
to sound the Martian atmosphere with microwaves to study water vapour.
However, the meeting was not entirely devoted to missions yet to leave
the
drawing board. Agustin Chicarro, Mars Express project scientist,
chaired a
session in which the Principal Investigators on several of the
spacecraft's
instruments gave updates on their instruments' progress. They are all
in an
advanced state of development, within allocated masses and on
schedule.
Briefings were also given on the Japanese spacecraft, Nozomi, with
which
Mars Express is collaborating, and the French space agency's Netlander
mission. Members from some of the instrument teams on board NASA's
Mars
Global Surveyor, the only spacecraft now in orbit around Mars,
summarised
some of their latest findings. These are demonstrating almost daily
how
a carefully designed and well-executed spacecraft can reveal what an
intriguing place Mars is.
IMAGE CAPTION:
[http://sci.esa.int/content/image/index.cfm?
aid=9&cid=32&oid=18625&objecttypename=news&ooid=18530]
Ancient channel of the Nile, revealed by radar
The bottom image, taken with a synthetic aperture radar (SAR) from the
Space
Shuttle, shows the ancient channel of the Nile which is hidden under
sand
in the top image taken with a conventional camera. The MEEM proposal,
discussed at the EGS, would use SAR to reveal structure hidden under
Martian sand. (source: JPL/NASA).
--
Andrew Yee
ay...@nova.astro.utoronto.ca
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