PLEASE NOTE:


*

CCNet, 14 October 1999
------------------------

     QUOTE OF THE DAY

     "A group of astronomers has discovered that a new molecule,
     nitrogen sulfide (NS), is contained within comets. The discovery
     is intriguing because scientists have long suspected that many
     molecules on Earth were brought here by comets. 'Could this
     material perhaps even be relevant to the origin of life?'"
              -- University of Massachusetts-Amherst, 13 October 1999



(1) NEW COMET MAY PUT ON A SHOW NEXT YEAR
    SpaceViews, 13 October 1999

(2) CHEMISTRY OF COMET HALE-BOPP MAY OFFER CLUES ABOUT EARLY   
    SOLAR SYSTEM
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(3) FIRST TUNGUSKA99 RESULTS
    Luigi Foschini <L.Foschini@isao.bo.cnr.it>

(4) VOLCANOES, CLIMATE CHANGE & TECTONICS ON PLANET VENUS
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(5) NASA-JPL ERROR
    Malcolm Miller <stellar2@actonline.com.au>

(6) WEB LINKS ON IMPACTS & IMPACT CRATERS
    Michael Paine <mpaine@tpgi.com.au>

(7) IMPACT-VOLCANISM CONNECTION PROBING
    Timo Assmuth <Timo.Assmuth@vyh.fi>

(8) IMPACT-VOLCANISM CONNECTIONS
    Michael Paine <mpaine@tpgi.com.au>

(9) IN SEARCH OF GRADUALIST EXPLANATIONS OF CLIMATE CHANGE
    SCIENTIFIC AMERICAN, October 1999

(10) 400 YEARS OF ASTRONOMY ON MERSEYSIDE
     Merseyside Maritime Museum, NMGM, Liverpool

(11) AUSTRALIAN SKYWATCHERS JOIN SEARCH FOR DEADLY ASTEROIDS
     Michael Paine <mpaine@tpgi.com.au>

===============
(1) NEW COMET MAY PUT ON A SHOW NEXT YEAR

From SpaceViews, 13 October 1999
http://www.spaceviews.com/1999/10/13b.html

A comet discovered last month may become bright enough to be visible to
the naked eye come the middle of next year, although it is unlikely to
be as brilliant as two other comets visible this decade.

Comet C/1999 S4 LINEAR was discovered last month by the LINEAR
automated telescope in New Mexico as part of an asteroid and comet
search program. First classified as an asteroid when discovered,
followup observations by other astronomers revealed a distinct fuzzy
coma around the body, evidence that the object is a comet.

Based on 18 observations in late September, astronomers at the Minor
Planet Center of the Smithsonian Astrophysical Observatory calculated a
parabolic, highly-inclined trajectory for the comet, passing about 0.75
AU (112 million km, 70 million mi.) from the Sun at its closest
approach in late July.

While the comet is very dim at the moment -- about magnitude 16,
requiring moderate to large telescopes to see it -- it will brighten
considerably as it approaches the Sun. Taking into account both
the comet's distance from the Earth and the Sun, it may brighten to as
much as magnitude 3 or 4 and thus be visible to the naked eye by July.

Predicting the brightness of comets is difficult, as it is hard to
estimate in advance not only the size of the comet but how much gas and
dust it will produce as it approaches the Sun and warms up. However,
current indications are that the comet will not be anywhere as bright
as comet Hyakutake in March 1996 or Hale-Bopp one year later.

The best time to observe the comet will likely be in mid-July, when the
comet is near its peak brightness. It will be seen in the northwest sky
after sunset in the northern hemisphere.

Copyright 1999, SpaceViews

MODERATOR'S NOTE: For further information about comet C/1999 S4 LINEAR
and how it was identified, see the IAU’s CBAT webpage at
<http://cfa-www.harvard.edu/iauc/07200/07267.html#Item1>

===============
(2) CHEMISTRY OF COMET HALE-BOPP MAY OFFER CLUES ABOUT EARLY   
    SOLAR SYSTEM

From Andrew Yee <ayee@nova.astro.utoronto.ca>

News Office
University of Massachusetts-Amherst

Contact: Elizabeth Luciano, luciano@admin.umass.edu

Release: Oct. 13, 1999

CHEMISTRY OF COMET HALE-BOPP MAY OFFER CLUES ABOUT THE EARLY SOLAR
SYSTEM, UMASS ASTRONOMER SAYS

Findings to be presented at meeting of the American Astronomical Society

AMHERST, Mass. -- A group of astronomers led by William Irvine of the
University of Massachusetts has discovered that a new molecule,
nitrogen sulfide (NS), is contained within comets. Although scientists
have long known that the molecule exists within dense interstellar
clouds, this is the first time it has been seen in a comet. The
findings are being presented during the annual meeting of the Division
of Planetary Sciences of the American Astronomical Society, currently
underway in Padua, Italy.

"The finding is significant," Irvine explains, "because astronomers
believe that comets hold the best samples of materials from which the
solar system was formed." Comets are icy masses which appeared in the
outer regions of the solar system when it was formed, 4.5 billion years
ago. Their distance from the sun has resulted in comets being heated
only minimally, preserving frozen gases that may give scientists clues
about what materials existed in space when the solar system formed.

The astronomers made the observation in March 1997, while conducting
separate research using the James Clerk Maxwell Telescope on Mauna Kea
Mountain in Hawaii. Collaborators on the project were Henry Matthews,
Joint Astronomy Center, in Hilo, Hawaii; Roland Meier, of the Institute
for Astronomy, University of Hawaii; Irvine, Matthew Senay, and Ricardo
Metz, of UMass; and Douglas McGonagle, formerly of UMass. The research
was sponsored in part by NASA.

The compound is the only known molecule in comets that contains both
nitrogen and sulfur. The molecule is a "radical," which means that it's
highly reactive, chemically. The discovery raises the question of
whether the NS in Comet Hale-Bopp has existed since the start of the
solar system, or if it was produced as a result of other compounds in
the comet breaking apart. Scientists will be able to determine that,
Irvine said, by examining exactly where in comets the NS lies. An
abundance in the head, or nucleus, would suggest original material, but
the amount cannot be measured from Earth. The way in which the
abundance of NS varies in the comet's atmosphere, called the coma,
would indicate whether the molecule is the result of other compounds
breaking apart due to the effect of sunlight, or whether it was
produced by chemical reactions. To make such a determination, the NS
molecule must be found in other comets.

The discovery is further intriguing because scientists have long
suspected that many molecules on Earth were brought here by comets.
"Could comets have provided molecules that became part of the oceans
and the atmosphere?" Irvine asks. "Could this material perhaps even be
relevant to the origin of life?"

=====================
(3) FIRST TUNGUSKA99 RESULTS

From Luigi Foschini <L.Foschini@isao.bo.cnr.it>

== PRESS RELEASE 12 OCTOBER 1999 ===

Poster presentation at DPS/AAS

The first scientific results of the italian scientific expedition
Tunguska99 will be presented at the 31st Annual Meeting of the Division
for Planetary Sciences of the American Astronomical Society (Padova,
Italy, October 10-15 1999). The poster will be presented in the Session
59 (late papers) on Thursday 14 october (6:00-7:30 PM). Moreover, the
abstract will be published on the "Bulletin of the American Astronomical
Society", vol. 31, n. 5, (1999) - see the attached file for winword.

Processing of the data is in progress, but preliminary analysis of data
collected on the lake suggests that the origin of the lake be not
related to the 1908 event. It constitutes, more likely, an ancient
volcanic depression filled up by a more than 50 m thick sedimentary
deposit of fluviatile origin. The future work will focus on the core
analysis, and on the detection of possible physical effects within the
sedimentary successions (i.e. gravitative failures of the slopes) that
could give important insights on the energy of the event.

In the poster will be available other notes about:

- the aerophotosurvey and GPS measurements, that will be used to
re-examine the material recorded in 1938 by Kulik;
- collected samples (wood, peat, pollen, rocks, gravel);
- gamma ray in-flight measurements; nearby the lake Cheko daughter
radionuclides from the 238U and 232Th natural chains have been recorded
(work is in progress to see for possible isotopes derived from man-made
activities).

Other information at http://www-th.bo.infn.it/tunguska/

For the Tunguska99 Press Office:
Luigi Foschini (mailto:L.Foschini@isao.bo.cnr.it)

===============
(4) VOLCANOES, CLIMATE CHANGE & TECTONICS ON PLANET VENUS

From Andrew Yee <ayee@nova.astro.utoronto.ca>

Carnegie Institution of Washington

Contact: Sean Solomon at 202-686-4370 x 4444
e mail: scs@dtm.ciw.edu

Tina McDowell in the Carnegie publications office at 202-939-1120
e mail: tmcdowell@pst.ciw.edu

New Link Believed to Exist Between Volcanoes, Climate and Tectonics on
Planet Venus

Volcanic eruptions on Venus may have altered that planet's climate so
dramatically that it caused tectonic stresses large enough to break
rock. These stresses are believed to have deformed the most abundant
type of terrain on the planet, called ridged plains. Such plains cover
about two thirds of the entire surface. Scientists Sean C. Solomon of
the Carnegie Institution of Washington's, Department of Terrestrial
Magnetism in Washington, D.C., and Mark Bullock and David Grinspoon of
the Department of Space Studies at the Southwest Research Institute in
Boulder, Colorado, will report their findings in the October 1, 1999,
issue of Science.

Although Venus is frequently referred to as Earth's sister, there are
fundamental differences between the two planets. The climate and
geological histories are two examples. On Earth, the mean surface
temperature has changed over time by only a few degrees. In contrast,
scientists now believe that the surface temperature on Venus may have
varied by more than 100 K. Researchers know that the Earth's surface is
the product of active plate tectonics, a process in which nearly rigid
plates are in steady relative motion and interact principally at their
boundaries. However, Venus shows no evidence for global plate
tectonics. So what gave rise to the tens of thousands of faults, known
as wrinkle ridges, that deform the ridged plains?

The evidence indicates that the formation of the wrinkle ridges was
triggered by the volcanic eruptions that produced the vast plains. The
plains-forming event, which occurred about 500 million years ago, was
the largest episode of volcanism in the planet's known history. The
estimated volume of this material is huge at least 100 to 200 million
cubic kilometers enough to blanket the planet in a layer 500 meters
thick. Evidence from impact craters suggests that the time it took from
the emplacement of the lava flows to the deformation that produced the
abundant wrinkles was quite short by geologic standards less than 100
million years.

The scientists modeled the climatic consequences of the large eruption.
They determined that a large change in surface temperature resulted,
which was transferred to the interior thereby causing the thermal
stress that created the ridges. The mechanism behind these results
begins with the fact that Venus is now and has long been a greenhouse
caldron. The surface temperature is about 740 K, and a global cloud
layer and the thick atmosphere, consisting of 97% CO2, keeps the heat
contained. Water and SO2 are important cloud constituents and also
affect the radiative balance of the atmosphere. According to the model,
the release to the atmosphere of additional water and sulfur gases
during the enormous volcanic eruption enhanced the greenhouse effect
and heated the planet by about 60 K over the ensuing 100 million years.
During this time, heating of the surface rocks in turn heated the
planet's interior. The hot material expanded such that it compressed the
surrounding area and thus created the abundant wrinkle ridges.

The model looked at the most significant episode of known volcanism on
Venus. However, because so much of the planet's surface dates from this
same period, the scientists know little about variations in climate
before this event. According to Sean Solomon, lead author of the study,
"What we are suggesting by extrapolation is that there may have been
many large volcanic events in the history of Venus, each of which led
to climate instabilities and to episodes of heating and cooling. Much
of the history of faulting on Venus may be linked to climate change
driven by major volcanic eruptions. This strong coupling among
volcanism, climate, and global-scale deformation can account for many
of the differences between Venus and Earth."

================
(5) NASA-JPL ERROR

From Malcolm Miller <stellar2@actonline.com.au>

   "Because Io is the innermost of Jupiter's moons, it lies in a
region with the highest levels of radiation from Jupiter, which
can wreak havoc with spacecraft instruments."

   This sentence apears in a press release (12 October) about the latest
Galileo flyby of Io. Let's hope that somebody in NASA-JPL knows there
are at least four satellites orbiting closer to Jupiter than Io. Errors
like this probably contributed to the loss of the Mars Climate Orbiter.

Malcolm Miller

===========
(6) WEB LINKS ON IMPACTS & IMPACT CRATERS

From Michael Paine <mpaine@tpgi.com.au>

Dear Benny,

Here are some links concerning Owen Fox's questions:

1. Aorounga - estimated age < 345 million years
http://gdcinfo.agg.nrcan.gc.ca:80/cgi-bin/crater/list_crater_html?e+Aorounga+/crater/africa_craters.html
(a frame from
http://gdcinfo.agg.nrcan.gc.ca:80/toc.html?/crater/world_craters.html )

2a. Ocean impact site off Tasmania. Can't find any links. I recall
hearing about some deep sea surveys of a possible impact site. It is
unlikely to be a few thousand years old.

2b. Tsunami and the South Coast of New South Wales (Shoalhaven) - the
last one may have hit less than 300 years ago.
http://wwwrses.anu.edu.au/~edelvays/tsunami1.html
(from http://www1.tpgi.com.au/users/tps-seti/spacegd7.html )

Thanks for posting my latest Explorezone article. The series is, of
course, aimed at people who are completely unfamiliar with NEOs. I
enjoyed Malcolm's poem.

Michael Paine

==================
(7) IMPACT-VOLCANISM CONNECTION PROBING

From Timo Assmuth <Timo.Assmuth@vyh.fi>

Dear Michael Paine/other fellow researchers,

as a student of NEO-catastrophism (and related/alternative
areas/directions), I read with interest the CCNet-posted recent article
for Explorezone.

One particular thing caught my attention. There was a mention of the
proposal that the Deccan traps be formed by the Chicxulub impact. The
correspondence in space and time (that is, the continental shift
corrected opposite direction, perhaps allowing for some variability due
e.g. to diversion of shock waves or of their effects, and the temporal
coincidence) of the impact structure and the magma bursts or other
sudden and violent terrestrial features could then more generally be
one (perhaps necessary but not sufficient) proof of the hypothesis of
impact-caused volcanism/other terrestrial disruptions at that time.

I just started to think whether anyone has tried to probe the
possibility of such causal links

- in other known cases of major impacts (to locate then-opposite magma
  bursts, and to determine their ages)
- in other known cases of major magma bursts/other geological anomalies
  indicating the possibility of collision shock effects (to locate
  then-opposite impact craters and to determine their ages; e.g. the
  great Siberian basalt field at the end of Permian might offer some
  clues to a missing large impact crater at that time particularly if
  the then-opposite area would not be subsequently subducted)
- in other known cases of both impacts and magma bursts/other geological
  anomalies (to check their spatial and temporal match).

Of course, the study of impact-generated volcanism and other remote or
even Earth-traversing effects may also be pursued by other theoretical
and empirical (e.g. paleogeomorphological/geophysical) means.

Such studies might notably contribute to the corroboration or (partial)
invalidation of the above hypothesis, and to our understanding of impact
effects.

Yours sincerely,
12.10.1999

Timo Assmuth
Dr.Sc. (environ.)
Docent of environmental science, University of Helsinki
Senior researcher
Finnish Environment Institute
P.O. Box 140
FIN-00251 Helsinki
Finland
tel. +358 9 40300 523
fax +358 9 40300 591
e-mail timo.assmuth@vyh.fi

==================
(8) IMPACT-VOLCANISM CONNECTIONS

From Michael Paine <mpaine@tpgi.com.au>

Hi Timo,

Both John Lewis and Duncan Steel mention the Deccan Traps in their
books (referenced on the Explorezone page). Duncan mentions a link
between Chicxulub impact, Deccan Traps eruption and K/T extinction and
also a newly discovered Falklands (South Atlantic) impact, the Siberian
eruption and the Late Permian extinction (345 Myr).

John also mentions the Columbia River basin in North American but
apparently no link has been found to an impact. He concludes "Thus
massive volcanism might make more sense as a consequence of, not an
alternative to, impact driven extinctions".

In preparing my article I had great difficulty finding a land mass on
the Earth with a land mass at the antipodal point (I used a battered
globe of the Earth). I settled on South East Asia and Brazil (at least
most Americans have an idea where Brazil is!). The point is that there
is a very high chance that the impact, the anti-nodal point or both will
be in ocean. As I indicate in my article, very few ocean bottoms are
older than 50 million years so linking ancient impacts to eruptions will
be very difficult.

Michael Paine

================
(9) IN SEARCH OF GRADUALIST EXPLANATIONS OF CLIMATE CHANGE

From SCIENTIFIC AMERICAN, October 1999
http://www.sciam.com/1999/1099issue/1099scicit5.html

DESERTING THE SAHARA

Dying plants harvest harsh surprises from climate change

Plants may seem to sit passively as climate decides their fate, but
scientists are beginning to believe that vegetation can strongly
amplify the climate's most subtle whims--sometimes with abrupt and
devastating results. A new computer simulation indicates that plants
helped to turn the Sahara from a lush grassland thriving with hippos
and elephants to its current condition as the world's largest desert.

The Sahara's succulent sojourn faced an abrupt end about 5,500 years
ago. In a matter of centuries, rainfall levels plummeted, the green
grasslands paled to a sandy yellow, and civilizations were forced to
relocate. Many scientists have assumed that human beings, who arrived
there 7,000 years ago, overused the land, which led to the quick loss
in vegetation. But the new simulations show that a steady but slow loss
of grasses--stemming from a gradual trend toward less rainfall
beginning about 9,000 years ago--ran wildly out of control.

"Climate modelers tend to think that vegetation is not important,
because it's only about 20 percent of the planet's surface area," says
Martin Claussen, leader of the team that designed the simulation at the
Potsdam Institute for Climate Impact Research in Germany. "We're now
seeing that we're not allowed to neglect land area."

John E. Kutzbach, a climatologist at the University of
Wisconsin‚Madison, is enthusiastic about the results because of their 
value in predicting future climate. "The idea that vegetation affects
climate hasn't been studied in detail," he says.

Both Kutzbach and Claussen had independently used earlier computer
simulations to watch how local weather affected Saharan plants, but
Claussen's latest simulations allowed his team to be the first to see
whether the plants themselves might effect change. Each of the team's
10 simulations began with the grasslands of 9,000 years ago and ended
with the arid desert of the present. The only external force they
introduced to their simulated climate was a gradual evolution of the
planet's orbit. About 9,000 years ago the earth's perihelion, the point
at which the planet passes closest to the sun, occurred in July, and
the North Pole was leaning more toward the sun. These two
circumstances, which then meant stronger summer sunlight for the
Northern Hemisphere and thus stronger monsoons to water a thirsty
Saharan grassland, have changed slowly ever since. The northward tilt
has shifted away from the sun, and perihelion now occurs in January.

During the first few thousand years of Claussen's simulation, this
transition manifested as a gradual loss of vegetation, presumably
because the monsoons were weakening. But the grassland's condition took
a dramatic nosedive starting about 5,500 years ago, the same time that
lakes and large animals begin to disappear from the fossil record. The
team speculates that the grasses of the early Sahara trapped moisture
that could evaporate and become new clouds--and new rain. As desert
sands took over, less water recycled to the atmosphere, so even less
rain fell and more plants died. "We can now explain the most important
changes in Saharan climate without taking human beings into account,"
says team member Claudia Kubatzki.

Kutzbach says that the findings of Claussen's group "open up a research
area rather than being the final word," but he agrees with their theory
that a vicious feedback cycle between vegetation and the atmosphere
could force dramatic changes. More specifically, the role that plants
play in their own sustenance can be key to their destruction.

Just because the Sahara apparently dried up because of natural causes
does not mean that humans are off the hook. Noting that as much as 30
percent of the rainfall in a tropical rain forest has cycled through
the leaves and roots of its Flora, Kutzbach and his colleagues suggest,
based on their own climate simulations, that cutting down trees could
produce a feedback cycle similar to what the earth's changing orbit set
off in the Sahara. "If you deforest, the rain washes down the Amazon
rather than going back into the clouds to form rain," Kutzbach says.
And pumping ever more carbon dioxide and other greenhouse gases into
the atmosphere may do more than slowly warm the planet. "We can't
specify what will happen," Claussen says, "but we're assessing the
danger of climate surprises."

  --Sarah Simpson

Copyright 1999, Scientific American

================
(10) 400 YEARS OF ASTRONOMY ON MERSEYSIDE

Merseyside Maritime Museum, NMGM, Liverpool

Saturday 16th October 1999

Programme:

09.30 Registration
09.45 The Telescopes of William Lassell, Jeff Hall, University of
      Liverpool.
10.10 Isaac Roberts, Philip Pennington, University of Liverpool.
10.35 Solar Eclipse Observations, Dr Eric Jones, Proudman
      Oceanographic Laboratory
11.00 Coffee
11.30 The Mars Observations of Dawes and Lassell, Patrick Moore
12.30 Lunch
13.40 Astronomy at Bidston Observatory, Martin Suggett, NMGM
14.05 George Higgs and the Solar Spectrum, Alan Bowden, NMGM
14.30 Liverpool to Leeds and Preston to Chester: The English Corridor
      of Astronomical Innovation, 1630 to the present day'. Allan
      Chapman, University of Oxford
15.30 Tea
15.50 The Astrophysics Research Institute, the Liverpool Telescope and
      modern Astronomy on Merseyside, Mike Bode, John Moores
      University
16.50 Plenary discussion and concluding remarks
17.30 End of Conference

The cost is  pounds 15  per delegate,  payable in advance,  including
lunch and tea/coffee

Contacts  are  Phil Pennington (tel 01744  739959)
or e-mail ggastro@liverpool.ac.uk

===============
(11) AUSTRALIAN SKYWATCHERS JOIN SEARCH FOR DEADLY ASTEROIDS

From Michael Paine <mpaine@tpgi.com.au>

An Australian ABC TV News item "Australian skywatchers join search for
deadly asteroids" is now available on the Internet at:
http://www.abc.net.au/news/science/space/1999/10/item19991006135658_1.htm
It includes Real Time video featuring interviews with Steve Larson from
the University of Arizona and Rob McNaught from Siding Spring, NSW. It
succinctly puts the case for a serious Australian effort to search for
Earth-threatening astoroids.

Michael Paine

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CCCMENU CCC for 1999

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