PLEASE NOTE:
*
CCNet 37/2002 - 19 March 2002
-----------------------------
"PHEW - that was close. A huge (sic) asteroid came close to
knocking
a great chunk out of the earth earlier this month and we didn't
even
realise it. Despite scientists constantly scanning the skies for
low-flying lumps of alien rock, somehow they managed (sic) to
miss this
one."
--Western Daily Press, 18 March 2002
(1) PLANET V HYPOTHESIS: LONG-DESTROYED FIFTH PLANET MAY HAVE
CAUSED LUNAR
CATACLYSM
Space.com, 18 March 2002
(2) "THAT WAS CLOSE": NEWSPAPER POINTS FINGER AT
ASTRONOMERS OVER 2002 EM7
MISS
Western Daily Press, 18 March 2002
(3) GETTING TO KNOW COMET BORRELLY
Astronomy.com, 18 March 2002
(4) SIX TELESCOPES ACT AS ONE
BBC News Online, 18 March 2002
(5) GEOLOGIST PROPOSES NEW SUPERCONTINENT
Andrew Yee <ayee@nova.astro.utoronto.ca>
(6) IN DEFENCE OF (AUSTRALIAN) SCIENCE MINISTERS
Nigel Holloway <nigel.holloway@ukaea.org.uk>
(7) DISCOVERY OF A PROBABLE IMPACT CRATER FIELD IN ITALY
Norbert Giesinger <norbert.giesinger@siemens.at>
(8) AND FINALLY: RANTS & MUSINGS ON DECEIT, MORONS &
RIGHT WING IDIOTS
Simon Mansfield <simon@spacer.com>
=============
(1) PLANET V HYPOTHESIS: LONG-DESTROYED FIFTH PLANET MAY HAVE
CAUSED LUNAR
CATACLYSM
>From Space.com, 18 March 2002
http://www.space.com/scienceastronomy/solarsystem/fifth_planet_020318.html
By Leonard David
Senior Space Writer
HOUSTON, TEXAS -- Our solar system may have had a fifth
terrestrial planet,
one that was swallowed up by the Sun. But before it was
destroyed, the now
missing-in-action world made a mess of things.
Space scientists John Chambers and Jack Lissauer of NASA's Ames
Research
Center hypothesize that along with Mercury, Venus, Earth, and
Mars -- the
terrestrial, rocky planets -- there was a fifth terrestrial
world, likely
just outside of Mars's orbit and before the inner asteroid belt.
Moreover, Planet V was a troublemaker.
The computer modeling findings of Chambers and Lissauer were
presented
during the 33rd Lunar and Planetary Science Conference,
held here March
11-15, and sponsored by NASA and the Lunar and Planetary
Institute.
It is commonly believed that during the formative years of our
solar system,
between 3.8 billion and 4 billion years ago, the Moon and Earth
took a
pounding from space debris. However, there is an on-going debate
as to
whether or not the bruising impacts tailed off 3.8 billion year
ago or if
there was a sudden increase - a "spike" -- in the
impact rate around 3.9
billion years ago, with quiet periods before and afterwards?
This epoch of time is tagged as the "lunar cataclysm" -
also a wakeup call
on the cosmological clock when the first evidence of life is
believed to
have appeared on Earth.
The great cover-up
Having a swarm of objects clobbering the Moon in a narrow point
of time
would have resurfaced most of our celestial next door neighbor,
covering up
its early history. Being that the Moon is so small, Earth would
have been on
the receiving end of any destructive deluge too.
Moon-walking astronauts brought back a cache of lunar material.
Later
analysis showed that virtually all impact rocks in the
"Apollo collection"
sported nearly the same age, 3.9 billion years, and none were
older. But
some scientists claim that these samples were "biased",
as they came from a
small area of the Moon, and are the result of a localized
pummeling, not
some lunar big bang.
There is a problem in having a "spike" in the lunar
cratering rate.
That scenario is tough to devise. Things should have been
settling down,
according to solar system creation experts. Having chunks of
stuff come
zipping along some hundreds of millions of years later out of
nowhere and
create a lunar late heavy bombardment is a puzzler.
If real, what were these bodies, and where were they before they
scuffed up
the Moon big time? The answer, according to Chambers and
Lissauer, might be
tied to the the Planet V hypothesis.
"The extra planet formed on a low-eccentricity orbit that
was long-lived,
but unstable," Chambers reported. About 3.9 billion years
ago, Planet V was
perturbed by gravitational interactions with the other inner
planets. It was
tossed onto a highly eccentric orbit that
crossed the inner asteroid belt, a reservoir of material much
larger than it
is today.
Planet V's close encounters with the inner belt of asteroids
stirred up a
large fraction of those bodies, scattering them about. The
perturbed
asteroids evolved into Mars crossing orbits, and temporarily
enhanced the
population of bodies on Earth-crossing orbits, and also increased
the lunar
impact rate.
After doing its destabilizing deeds, Planet V was lost too, most
likely
spinning into the Sun, the NASA team reported.
The temporary existence of more than 4 planet-sized bodies in the
inner
Solar System is consistent with the currently favored model for
the
formation of the Moon. Work by Chambers and Lissauer also
supports the view
that our Moon is a leftover of a massive collision between Earth
and a
Mars-sized body 50 million to 100 million years after the
formation of the
Solar System.
Striking view
Wendell Mendell, a planetary scientist here at NASA's Johnson
Space Center,
said the new theory is intriguing.
"This idea and others within the last few years show that
the Solar System
is filled with all sorts of gravitational resonances...that a lot
of
potential orbits in the Solar System are chaotic and
unstable," Mendell told
SPACE.com. "My sense is that this is a new idea. It's
another thing to throw
into the pot that's not totally crazy."
The work suggests there's a match up in timing, Mendell said,
with asteroids
striking the Moon and causing the effects that are seen in the
dating of
Apollo lunar rocks.
"By thinking that the Solar System was really quite
different in a major way
with an extra inner planet, we might be able to develop some sort
of
self-consistent scenario that explains a lot of things. But all
this is at
the very early stages now," Mendell said.
"We're moving into a really new regime," Mendell added,
"where the Solar
System is not a static dynamic place from day one to now. It
really might
have had some nuances and synchronicities associated with it that
we have
not really tried to exploit before."
It takes a drill hole Setting the early Solar System and lunar
history
record straight means going back to the Moon.
"The Moon is still the keystone to our understanding of the
Solar System,"
NASA's Mendell said.
That too is the view of Apollo 17 astronaut, Harrison
"Jack" Schmitt.
Getting back to the Moon to sort out the real story is a must, he
said.
"You're going to have to be very, very specific on what
sites you go to
collect new samples," Schmitt told SPACE.com. "It may
be very difficult to
get an answer without using missions to fairly large impact
craters that
penetrate through the ejecta. Those impacts are sort of a drill
hole into
the lunar crust," he said.
Dating service
Places on the Moon where older, large basins have deposited
ejecta are ideal
research zones, Schmitt said. Digging into such sites could yield
impact
glass formed by basins perhaps dating older than 3.9 billion
years old, he
said.
Just taking spot samples -- say from the Moon's South Pole Aitken
basin --
could be risky, in terms of uncovering the Moon's rocky history,
Schmitt
said. Such a huge area would take multiple robotic or human
exploration
missions, each with significant roving abilities.
Also known as the "Big Backside Basin," Aitken is the
largest impact crater
on the Moon, and one of the biggest in the Solar System.
For the near term, sets of low-cost, mini-robotic landers
carrying
specialized gear would be ideal in opening up the Moon to further
exploration, Schmitt said.
"Numbers of targeted missions could get a lot of great
information on some
of these fundamental questions that we still haven't been able to
answer,"
Schmitt said.
Getting back to the Moon with a settlement for resource
exploitation is
another step forward. From such a site, human explorers can
survey various
lunar locales - even the Moon's side that we Earthlings never
see, Schmitt
said. "Then we can do the kind of thing that Apollo did for
the near side of
the Moon," he said.
Copyright 2002, Space.com
=============
(2) "THAT WAS CLOSE": NEWSPAPER POINTS FINGER AT
ASTRONOMERS OVER 2002 EM7
MISS
>From Western Daily Press, 18 March 2002
http://www.westpress.co.uk/
PHEW - that was close. A huge (sic) asteroid came close to
knocking a great
chunk out of the earth earlier this month and we didn't even
realise it.
Despite scientists constantly scanning the skies for low-flying
lumps of
alien rock, somehow they managed (sic) to miss this one.
Apparently the asteroid, named 2002 EM7 and around 100 metres
across sneaked
in through a blindspot.
It was only picked up after moving past the earth, missing us by
some
450,000 kms, which in galactic terms is regarded as a pretty
close shave.
Astronomers have been arguing for more funding to improve their
chances of
spotting these potentially deadly asteroids.
No doubt they will be making sure they don't miss 2002 EM7 as it
threatens
to strike the earth on its way back.
But I wouldn't put your house on it. The odds of it hitting on
its return
are at best one in six million.
Copyright 2002 Western Daily Press.
see also: CLOSE CALL FOR EARTH
http://www.heraldsun.news.com.au/common/story_page/0,5478,3976336%255E11869,00.html
==============
(3) GETTING TO KNOW COMET BORRELLY
>From Astronomy.com, 18 March 2002
http://www.astronomy.com/Content/Dynamic/Articles/000/000/000/795nbiab.asp
At this week's Lunar and Planetary Science Conference, space
scientists
presented new insight on Deep Space 1's recent target, Comet
Borrelly.
by Vanessa Thomas
On September 22, 2001, NASA's Deep Space 1 probe proved
victorious in a
daring adventure when it introduced a comet called Borrelly to
the people of
Earth. In a chancy maneuver that day, Deep Space 1 altered our
view of
Borrelly as a mysterious, dust-cloaked object to an exciting
astrogeology
subject.
Designed not as a science mission but to test new technologies,
Deep Space 1
wasn't built for a risky comet rendezvous. In fact, mission team
members
weren't sure whether the spacecraft would even be able to find
the comet to
take any pictures at all. But when the encounter was over,
scientists had
their most detailed images of a comet's nucleus and the best
opportunity yet
to learn about the structure and history of comets.
Less than six months later, on Wednesday, March 13, scientists at
the 33rd
Lunar and Planetary Science Conference presented the first round
of science
results from Deep Space 1's successful meeting with Comet
Borrelly. In
addition to Borrelly's spiky jets, dusty environment, fragmented
ice,
solar-wind interaction, and composition, presenters discussed the
comet's
varied and fascinating nucleus.
>From their first look at Deep Space 1's pictures of Comet
Borrelly,
planetary scientists knew its nucleus was one of the darkest
objects they'd
ever seen - a surprising achievement for something composed
largely of
bright ice. Overall, the comet's nucleus reflects no more than 3
percent of
the light that hits it.
"The average geometric albedo is black, black, black, and
ranges from
extremely black to very black," said University of Tennessee
geologist Dan
Britt, who described the nucleus's color as being like that of
photocopier
toner. Amidst Borrelly's gloominess, however, Britt managed to
identify four
main types of landforms on the strange mini-world.
Mottled terrain covers the extended comet's far opposite ends,
which are
darker than Borrelly's mid-section. These rough areas are filled
with
bowl-shaped depressions, hills, streaks aligned with the
nucleus's long
axis, and notable variations in brightness. The ends lack any
strong
association with the comet's jets.
Among the mottled terrain at the ends of the comet's nucleus are
spots
darker than anything else on Borrelly. These black patches
reflect just 0.7
to 1 percent of incoming light, Britt reported.
The middle of the nucleus consists of Borrelly's brightest and
smoothest
terrain. It also contains the comet's fourth type of feature:
dark,
flat-topped mesas surrounded by bright slopes. According to
Britt, the
smooth terrain and slopes probably reveal the comet's freshest
material and
are the likeliest source of its jets.
At the end of his talk, Britt pointed to another curious
characteristic on
Comet Borrelly's nucleus. Several ridges and fractures cut across
the
comet's slimmest section, which separates its two lobes. Another
presenter,
Jürgen Oberst of Germany's DLR Institute of Space Sensor
Technology and
Planetary Exploration, added that a three-dimensional stereo
elevation map
of the nucleus shows that the smaller end of the
bowling-pin-shaped nucleus
is not aligned with but tilted (by 30º to 50º) relative to the
larger half.
Britt and Oberst suggest these observations indicate Borrelly's
nucleus may
actually be a contact binary - composed of two pieces loosely
bound to each
other.
Copyright 2002, Astronomy.com
=============
(4) SIX TELESCOPES ACT AS ONE
>From the BBC News Online, 18 March 2002
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1879000/1879134.stm
By Dr David Whitehouse
BBC News Online science editor
Astronomers have combined the visible light from six telescopes
to produce a
single, high-resolution image of a distant multiple-star system.
The feat is being described as a major advance in humanity's
ability to
probe the Universe.
The synthesized image shows the three component stars of Eta
Virginis,
located about 130 light-years from Earth.
To obtain such detail in a single, normal telescope would have
required a
massive mirror that measured 50 metres (164 feet) across. Nothing
on such a
scale currently exits.
Scientists are delighted because the picture shows how the
technique known
as interferometry can be used to study stars in the optical
(visible) region
of the spectrum.
Separation distance
"This development makes it possible to 'synthesize'
telescopes with
apertures in excess of hundreds of metres," said Dr Kenneth
Johnston,
Scientific Director of the US Naval Observatory (USNO), which has
been
working on the project with the Naval Research Laboratory (NRL),
and Lowell
Observatory.
"It will lead to the direct imaging of the surfaces of stars
and of star
spots, analogous to the sunspots on the Sun.
"This technology can also be applied to space systems for
remote sensing of
the Earth and other objects in the Solar System, as well as stars
and
galaxies."
Optical interferometers combine the light from several
independent
telescopes to form a "synthetic" telescope whose
ability to make a
high-resolution image depends not on the size of any individual
telescope in
the network but on the maximum separation between the telescopes.
Radio interferometry has been carried out for almost 50 years but
the field
of optical interferometry is a new and rapidly developing branch
or
astronomy.
Distant planets
Many scientists believe optical interferometers could be the
answer to the
prohibitive costs and immense technical difficulties that
currently hold
back the development of extremely large, single-mirror
telescopes.
That said, it is no easy task linking optical telescopes together
either. To
merge the six beams from the six telescopes focused on Eta
Virginis, the
researchers had to design a new type of hybrid beam combiner
The twin Keck 10-metre (32 feet) telescopes on Hawaii were
combined for
preliminary observations last year and the European Southern
Observatory's
Paranal Observatory will eventually combine the light from four
eight-metre
(26 feet) telescopes.
Stellar astrophysics should be revolutionised by the capability
to directly
image stars.
Ultimately, when employed in space with the experience collected
from
ground-based instruments, optical interferometry may develop the
capability
to image Earth-sized planets orbiting distant stars.
'On the brink'
We could then study the atmospheres of these worlds to see if the
telltale
signs of life are present.
"Remember the early days of radio interferometry and look at
the world- wide
arrays we routinely use today," said Dr Johnston.
"We've gone from simple two-element arrays to
continent-sized ones with 10
or more antennae that produce extremely fine-scale images of
distant
quasars.
"We are standing on the brink of achieving similar results
for visible-light
sources."
In the near future, the researchers will be commissioning all of
the
remaining stations on to which any of the six telescopes can be
mounted for
a maximum array size of 430 metres (1,410 feet), the largest of
all current
imaging interferometer projects.
Copyright 2002, BBC
============
(5) GEOLOGIST PROPOSES NEW SUPERCONTINENT
>From Andrew Yee <ayee@nova.astro.utoronto.ca>
News Services
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina
Contact:
David Williamson, (919) 962-8596
For immediate use: March 18, 2002
No. 155
Years of research, thought lead geologist to propose new
supercontinent
Columbia
By DAVID WILLIAMSON, UNC News Services
CHAPEL HILL -- In 1912, German meterorologist Alfred Wegener
proposed a
theory that first angered and then intrigued scientists and
others ever
since.
Continents shifted around at far slower than a snail's pace
throughout
Earth's history like pieces of a puzzle, drifting together and
pulling apart
to form oceans, he said. Part of the eventual fascination with
his idea came
from globe-gazers' observation that continents such as
Africa and South America look like they could fit together
snugly.
Following up on Wegener and others' work, a University of North
Carolina at
Chapel Hill geologist believes he has discovered a new,
long-vanished
supercontinent. That early amalgamation of most of the world's
continents in
one vast land area later split up several times, reformed and
divided again
to begin shaping Earth's current continents.
The primeval supercontinent, which Professor John J.W. Rogers
named
Columbia, existed more than 1.5 billion years ago and is older
than any of
several giant landmasses previously proposed.
"I named the supercontinent Columbia because some of the
best evidence for
its existence is in the Columbia River region of western
North America,"
Rogers said. "Starting at about 1.8 billion years ago, all
of the continents
existing at that time began to collide into a single land
area."
Rogers describes his ideas in a scientific paper with fellow
geologist Dr.
M. Santosh of Kochi University in Japan published in the current
issue of
the Gondwana Research, a quarterly journal devoted to studies of
Earth's
early land masses.
The east coast of India became attached to western North America,
with
southern Australia against western Canada, he said. Most of
present South
America rotated so that the western edge of Brazil
lined up with eastern North America, forming a continental margin
that
extended into the southern edge of Scandinavia.
"This formed an area that stretched about 8,000 miles from
southern South
America to northern Canada and was about 3,000 miles across at
its widest
part," Rogers said.
Columbia began to break up about 1.5 billion years ago, and its
fragments
moved around the Earth independently for several hundred million
years, he
said. About a billion years ago, the fragments came together
again to form a
new supercontinent, called Rodinia. Rodinia lasted until about
700 million
years ago before it too broke into several fragments.
These chunks moved independently until 250 million years ago,
when the
supercontinent Pangea formed, Rogers said. Pangea then began to
break up
almost immediately to form the world's present continents.
"This sequence of formation and dispersal of supercontinents
is clearly
caused by movements deep within the Earth in a layer scientists
call the
mantle," he said. "The exact mechanism is still
being worked out, and hopefully the discovery of Columbia will
contribute to
understanding it."
Magnetic and geologic evidence for supercontinents becomes less
certain and
more controversial as the age of the supercontinent increases,
Rogers said.
For that reason, the shape of Columbia
and even its existence is less certain than that of Rodinia.
Originally trained as a petrologist and geochemist, the UNC
scientist came
up with his ideas while traveling in the Orkney Islands off
Scotland's north
coast. He based them on data he collected in India, East Africa
and Saudi
Arabia as U.S. leader of a joint Indian and U.S. cooperative
study of the
Precambrian evolution of southern India and on data published by
other
scientists.
Geologists date ancient rocks by measuring radioactive decay of
uranium and
lead isotopes.
Comparisons of such information and rock types around the world
reveal what
regions used to be connected.
Rogers served as guest editor of the special issue, much of which
is devoted
to papers by other authors evaluating the proposed Columbia
supercontinent
and related information. The International Association for
Gondwana
Research, based in Kochi, Japan, publishes the journal.
- 30 -
Note: Rogers can be reached at (919) 962-2581 (w) or jrogers@email.unc.edu .
============================
* LETTERS TO THE MODERATOR *
============================
(6) IN DEFENCE OF (AUSTRALIAN) SCIENCE MINISTERS
>From Nigel Holloway <nigel.holloway@ukaea.org.uk>
Benny
Although some of the statements attributed to Australian Science
Minister
Peter McGaurin did not at first encourage a defence, I have some
sympathy
with his position.
He is faced with a situation in which Australian astronomy
already has a
budget far larger than the amount of Spaceguard funding 'in
dispute'. In
this situation, a Minister may reasonably ask why he should be
involved at
all. The distribution of the budget to astronomy projects is not
done in
detail by him, but by research budget panels or committees. Those
panels, no
doubt containing several members with more knowledge of astronomy
than the
Minister, are telling him, either directly or implicitly by their
actions,
that the Spaceguard project is less important than their least
important
current astronomy project. By any measure meaningful to the
public or a
minister, something less important than the least important
current
astronomy project is very unimportant indeed. It is little wonder
that the
Minister feels no need to take it seriously when Australia's
astronomy
funding bodies do not.
The 'dispute' here is with Australia's astronomers. They, either
directly or
indirectly, are saying this (Spaceguard survey) is not important.
Let us
hope, for their sake, that they have good reasons - Ministers
don't like to
find that their sub-ordinates have been playing silly games at
their
expense.
NJH
===========
(7) DISCOVERY OF A PROBABLE IMPACT CRATER FIELD IN ITALY
>From Norbert Giesinger <norbert.giesinger@siemens.at>
Dear Dr. Peiser,
looking in the Web trough the 2002 LPS contributions, I found the
following
concerning a probable crater field in Italy. (Looking on it
superficially, I
hope it is not a relict from the 2nd world war).
http://www.lpi.usra.edu/meetings/lpsc2002/pdf/
See 1075.pdf
Greetings
Norbert Giesinger
===========
(8) AND FINALLY: RANTS & MUSINGS ON DECEIT, MORONS &
RIGHT WING IDIOTS
>From Simon Mansfield <simon@spacer.com>
Dear Benny,
I write in reply to your "shock" at the comments made
by the Australian
Minister for Science Peter McGauran.
This is the same type of moronic response to virtually all
environmental
issues we have come to expect from conservative governments the
world over.
But, Benny, in one of your email journals - "CLIMATE SCARES
& CLIMATE
CHANGE" you wail against the doomsayers of climate change,
so why do you now
wonder that politicians like Peter McGauran don't take scientists
and their
issues of concern seriously.
The systematic attack on climate scientists orchestrated by the
entranced
interests of transnational corporations has been in part
responsible for the
ongoing reduction in the public's trust and respect for
scientists.
Why you continue to promote the deceitful agenda of organizations
like The
Greening Earth Society and Tech Central Station amazes me,
Meanwhile you
give oxygen to ignorant fools like John Daly who has published
some of the
most violent hate speech against scientists I have ever read.
I'm sorry Benny, but your failure to stand up for climate
scientists against
the vicious attacks of so many vested interests and their
pre-paid
politicians leaves me aghast. And now you wonder why right wing
idiots like
Peter McGauran are so contemptuous of scientists when dealing
with an issue
that might not effect us or any future generation for a thousand
if not a
million years.
Regards,
Simon Mansfield
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*
CCNet ESSAY: KEEP WATCHING THE SKIES:
COMET-CHASERS & PLANETARY PROTECTION
--------------------------------------------------------------------------
"The chances that LUCIFER'S HAMMER would hit the Earth
head-on were
one in a million, then one in a thousand, then one in a hundred.
And
then..."
by Duncan Lunan [ astra@dlunan.freeserve.co.uk
] and Gordon Ross
[In February 2002, the Cambridge Conference Network carried
articles on
using solar sails to deflect incoming NEO's, and on storing
nuclear weapons
in the Lagrange points to protect Earth. The two
concepts are combined in
the article below, which proposes a small fleet of parabolic
solar sails,
'Comet-chasers' to be stationed at the Lagrange points.
The style is informal because the original was commissioned by
David
Langford for the short-lived British magazine Extro, in 1982,
during the
first scare about Comet Swift-Tuttle, but did not appear because
Extro
ceased publication. Gordon Dick (now Gordon Ross) designed the
Comet-Chaser
for a version submitted to the Hughes Aircraft/Griffith Observer
essay
contest, in 1986. The essay wasn't placed, but Space Policy
published two
letters from us on the subject. After Swift-Tuttle returned in
1992 and the
threat again became apparent, the revised article was published
in Analog in
October 1994, with illustrations by Sydney Jordan. A longer one
was
published by ASTRA, the Association in Scotland to Research into
Astronautics, in our journal Asgard in May 1995. A shorter piece
appeared in
the Glasgow Herald in March 13th, 1998, as part of the extensive
coverage
which another scare had gained for Jay Tate's lectures to ASTRA
in Airdrie
and Glasgow. Since then the Glas-weg-ian has run a piece,
illustrated with a
photo of a Comet-chaser model by Gordon Ross. We are about to
print the
version below in Asgard as part of 'The Politics of Survival', an
ASTRA
discussion pro-ject on threats to Earth of all kinds and how to
avert them.
DL]
[continued]