PLEASE NOTE:
*
Date sent: Fri, 24 Oct
1997 15:31:44 -0400 (EDT)
From:
HUMBPEIS <B.J.PEISER@livjm.ac.uk
Subject: CC
DIGEST 24 October 1997
To:
cambridge-conference@livjm.ac.uk
Priority: NORMAL
CAMBRIDGE-CONFERENCE DIGEST 24 October 1997
1) IS THE EARTH REALLY GETTING HOTTER?
2) EXPLORING MARS FOR EVIDENCE OF PAST OR PRESENT LIFE
3) LES SENTINELS DE L'ESPACE
=======================================================================
1)
IS THE EARTH REALLY GETTING HOTTER?
from: The Times, 24 October 1997, p.21 (letter to the editor)
Dr David Carson's response (letter, October 20) to Nigel
Hawkes's
question, "Is the Earth really getting hotter?" will
have served a
useful purpose if it helps to bring out into the open the fierce
debate which is going on between the global warming theorists and
the sceptics. Readers of the NEW SCIENTIST (article,
"Greenhouse
Wars - why the rebels have a cause", July 19) will have been
left
in no doubt that passions run high, and that there are
heavyweights on both sides. Scientific consensus there is not.
The rise in temperature of about 0.6C over the last century is
debatable because ground stations were being absorbed by
urbanisation over the period: cities are warmer than the
countryside. However, whatever warming did occur took place in
the
first half of that period, whereas 70 per cent of the increase in
carbon dioxide emissions occurred in the secon half. Nigel Hawkes
righly makes the point that the satellite record has been
confirmed by the ballon record, and confirms that very little
warming, if any, has occurred since 1945.
The most credible explanation for climatic variability is the
impact of solar flares on the earth's atmosphere, as put forward
by researchers at the Danish Meteorological Institute. The
politicisation of this issue is fascinating and will be on full
display at the Kyoto summit in December. Perhaps we should ask Dr
Carson and the other believers to state what observed facts
w o u l d disprove the theory, which at the moment is
showing all
the signs of a scientific hypothesis in terminal decline.
Michael Hird, 4 Copperfield, Beaconsfield, Buckinghamshire
======================================================================
2) EXPLORING MARS FOR EVIDENCE OF PAST OR PRESENT LIFE
from: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov
Elizabeth Carter
NASA Ames Research Center Oct. 17, 1997
Moffett Field, CA
650/604-2742
ecarter@mail.arc.nasa.gov
RELEASE: 97-75AR
EXPLORING MARS FOR EVIDENCE OF PAST OR PRESENT LIFE
Alternative exploration strategies designed to detect evidence
of
past or present life on Mars are the subject of a presentation to
be
given by NASA's Dr. Jack Farmer at the Geological Society of
America
(GSA) Annual Meeting in Salt Lake City, Utah, on Oct. 20, 1997..
Farmer, an exobiologist and paleontologist at NASA's Ames
Research
Center, Moffett Field, CA, asks the question, "if there was
there
life on Mars, where would it be found?" The crucial first
step in
implementing an exploration strategy is identifying the best
places
to look, he states.
"A close synergy between orbital and landed science will
be essential
for effective site selection to explore for past life,"
Farmer said.
In exploring for a Martian fossil record, present scenarios
assume
that rover missions in 2001 and 2003 will gather and cache
samples
for possible return-to-Earth mission in 2005. A critical step is
to
locate accessible surface outcrops of water-formed sedimentary
deposits on Mars. The effectiveness of a sample return mission in
addressing the question of past Martian life will be
significantly
enhanced by
1) obtaining high spatial resolution data from important sites
during
the 2001 orbital mission,
2) delivering highly mobile robotic platforms to
exopaleontological
sites in 2001 and 2003, e.g. rovers that are capable of multiple
kilometer traverses during nominal mission times, and
3) carrying out in-situ mineralogical and geochemical analyses
of a
variety of rock types as a basis for selecting samples for return
to
Earth.
Potentially important targets include fine-grained, clay-rich
detrital sediments, water-lain volcanic ash deposits, and
chemical
precipitates-lithologies that on Earth have been shown to be
especially favorable for preserving fossil biosignatures of
microbial
life.
According to Farmer, exploring for Martian life will require a
fundamentally different approach than exploring for a fossil
record.
A deep subsurface hydrosphere, touted as the most likely haven
for an
extant biota on Mars may yet exist beneath the Martian cryosphere
at
a depth of several kilometers. However, during the Mars Global
Surveyor (MGS) Program, robotic platforms will be unable to
penetrate
deeper than a few meters.
Farmer believes that the technological challenge of deep
subsurface
drilling presently provides the most compelling scientific reason
for
mounting human missions to Mars. But as a first step in planning
drilling missions, systematic orbital searches using high spatial
resolution multispectral imaging should be undertaken sometime
during
the MGS Program (perhaps in 2003) to identify
spatially-restricted
thermal anomalies, and concentrations of water, methane or other
reduced gases that may indicate the presence of near surface
hydrothermal systems.
=======================================================================
3)
LES SENTINELS DE L'ESPACE
from: Neil Forsyth <Neil.Forsyth@ANGL.unil.ch
I now have more information concerning the French television
programme shown on the local Swiss channel that I mentioned in an
earlier mailing.
It was called "Les sentinels de l'espace" and was
primarily about
astronomers who search the skies for NEO's. They were French,
working
at an observatory near Nice. Another interview was with a
scientist
in Lyon. The programme was also about the major past impacts, and
the
likelihood of another, next year or in a million years. A
good
general introduction to the subject, I thought, but not for an
expert
audience, of course. It lasted half-an hour or so.
The programme is distributed by Galaxy Press, 48 rue du
Paradis,
F-75010 Paris. Fax: +33 1 44 83 07 27.
Neil Forsyth
University of Lausanne
CH-1015 Lausanne
Switzerland
+41 21 692 29 88
e-mail: Neil.Forsyth@ANGL.unil.ch