PLEASE NOTE:
*
CCNet 36/2002 - 18 March 2002
-----------------------------
"I'm not going to be spooked or panicked into spending
scarce
research dollars on a fruitless attempt to predict the next
asteroid. I'm
just not convinced that the hype and alarm and even
fear-mongering is
enough to justify an instant investment."
--Peter McGauran, Australian Minister for Science, 17 March
2002
"One of the largest asteroids known to have approached the
Earth
zipped past about 450,000 kilometres away on March 8 - but nobody
recorded it until four days later."
--Jeff Hecht, New Scientist, 15 March 2002
SHOULD SPACEGUARD FUNDING BE RESTORED IN AUSTRALIA?
http://news.ninemsn.com.au/sixtyminutes/stories/2002_03_17/story_530.asp
Yes 92%
No 8%
(1) ASTEROID BUZZES EARTH FROM 'BLIND SPOT'
New Scientist, 15 March 2002
(2) DEEPER IMPACT
Sunday Sunrise, Australian Channel 7 TV, 17 March 2002
(3) THE THREAT ABOVE
60 Minutes, 17 March, 2002
(4) ASTEROIDE PASSA DE RASPAO PELA TERRA
Globo.com, 16 March 2002
(5) AMATEUR ASTRONOMER DETECTS NEAR EARTH ASTEROID
Der Spiegel, 15 March 2002
(6) RADAR REVEALS BIG SPLASH ON MERCURY
Sky & Telescope, 15 March 2002
(7) AMATEUR ASTRONOMER DISCOVERS NEW COMET
Ron Baalke < baalke@jpl.nasa.gov
>
(8) MANITOBA METEORITE SECOND LARGEST DISCOVERED IN CANADA
Andrew Yee < ayee@nova.astro.utoronto.ca
>
(9) REGIONAL K/T EXTINCTION & TERTIARY DISPERSAL OF SURVIVORS
Hermann Burchard < burchar@mail.math.okstate.edu
>
(10) AND FINALLY: NASA STUDY FAVOURS 'POWER NAP' AT WORK
Ananova, 18 March 2002
==============
(1) ASTEROID BUZZES EARTH FROM 'BLIND SPOT'
>From New Scientist, 15 March 2002
http://www.newscientist.com/news/news.jsp?id=ns99992052
One of the largest asteroids known to have approached the Earth
zipped past
about 450,000 kilometres away on March 8 - but nobody recorded it
until four
days later.
The object, now called 2002 EM7, was hard to spot because it was
moving
outward from the innermost point of its orbit, 87 million km from
the Sun.
When it passed closest to the Earth - just 1.5 times the distance
to the
Moon - it was too close to the Sun to be visible.
Asteroids approaching from this blind spot cannot be seen by
astronomers. If
a previously unknown object passed through this zone on a
collision course
with Earth, it would not be identified until it was too late for
any
intervention.
Astronomers have made numerous calls in recent years for more
funds to
catalogue near-Earth objects and refine their orbits. This would
reduce the
number of unknown objects that could catch us unaware, and give
early
warning of potential future collisions.
Bigger than Tunguska
An asteroid-hunting telescope operated by the MIT Lincoln
Laboratory first
recorded the new asteroid on March 12, as it moved away from the
Earth and
more of its bright side came into view.
Further observations allowed Timothy Spahr of the
Harvard-Smithsonian Center
for Astrophysics to calculate its orbit. He found that it has a
323-day
orbit that takes it as far as 188 million km from the Sun.
Invisible to the unaided eye, 2002 EM7 is too small to be classed
as a
"potentially hazardous asteroid". But it is probably
between 50 to 100
metres across, making it larger than the object that exploded in
1908 over
the Tunguska region of Siberia, flattening trees over 2000 square
kilometres.
The approach puts it among the 10 closest known approaches by
minor planets,
says Brian Marsden of Harvard-Smithsonian. More ominously, only
one of the
10 closest objects was larger. This was 1996 JA1, which passed
only slightly
closer to the Earth on 19 May 1996.
The discovery adds to the list of asteroids which are long shots
to hit the
Earth in the next century. Preliminary calculations indicate 2002
EM7 has
Several chances to hit the Earth in that period, with odds of one
in six
million to one in a billion, Marsden told New Scientist. Further
observations are likely to lengthen the odds.
Jeff Hecht
© Copyright Reed Business Information Ltd.
==============
(2) DEEPER IMPACT
>From Sunday Sunrise, Australian Channel 7 TV, 17 March 2002
http://new.i7.com.au/sunday_sunrise/story.php?story=34
Australian scientists used to scour the sky for potentially
dangerous
"near-Earth objects". But as John Collis reports, the
Coalition government
cut funding for the "Spaceguard" program.
John Collis: It's half a lifetime since we slipped our mortal
bonds where
the blue of the day meets the endless night.
And still it's hard to see our home for what it really is.
Spaceship Earth, on her eternal circuit of the Sun; our course
charted in
chaos when the planets were born, lumbering along at 30
kilometres a second,
the road ahead anything but clear.
Dr Duncan Steel, Salford University, UK: We know now we live in a
cosmic
shooting gallery. These things are whizzing by the Earth with
alarming
frequency. This is something we had no idea about only 20 years
ago.
John Collis: Cosmic rubble from marble-size to mountains,
countless
thousands of asteroids swirling in a galactic mobile of chaotic
orbits -
many routinely intersecting the Earth's. Often passing within a
cosmic
whisker of disaster, and some preordained for catastrophe.
Professor Paul Davies, Macquarie University: Most of these things
just come
out of the blue, there would be no warning from looking up into
the sky
until it was already entering the atmosphere and then we're
talking seconds
for it to reach the ground. We're talking about a million
mega-tonne
explosion. That's a million city bursting bombs all going off at
once.
John Collis: A scenario that for scale, tone and colour would
usually ring
alarm bells in the reality-check department. But not when
scientists of
international standing like Professor Paul Davies fire up with
probabilities
translated into hair-raising odds.
Professor Paul Davies: We are talking here about something of
devastating
proportions and there is about a one in a million chance of it
happening
next month.
John Collis: Odds in statistical terms shorter than the chance of
winning
Lotto suggesting by the same process we're more likely to die in
an asteroid
impact than an airline crash.
Professor Paul Davies: We are talking here about a quantifiable
threat. It
is still a small threat - and that's really important because I
don't want
people to lie awake at night worrying about it but we are talking
about,
say, a one in a 100,000 chance per year of an event like this
happening.
John Collis: In geological terms, an event neither unprecedented
nor rare,
our planet pockmarked with the evidence.
Massive craters like Wolfe Creek in Western Australia, a
kilometre across,
punched in the desert by an asteroid of office block proportions
300,000
years ago.
The gaping Barringer Crater in Arizona, where disaster came out
of the blue
just 50,000 years ago.
In living memory, the thousands of hectares of forest laid waste
in 1908
when an incoming comet exploded over Siberia, the flash observed
as far away
as England.
And identified in satellite scans, older and much bigger scars
like this,
buried beneath Mexico's Yucatan peninsular. 300 kilometres across
- possibly
the one that killed the dinosaurs and reset the Earth's
evolutionary clock
65 million years ago.
A phenomenon once thought improbable, that unfolded before our
eyes just
seven years back as fragments of a shattered comet slammed into
our giant
solar sibling, Jupiter.
And for any doubters left, the wake-up call came last Christmas
Eve when
NASA observers in Hawaii found a previously uncharted asteroid
heading
straight for Earth.
YB5 they called it, a space mountain 300 metres wide, closing
fast and
likely to pass between the Moon and Earth.
It was 40 hours before enough was known to recalculate in favour
of Earth
and it slipped by on January 7th at roughly twice the Moon's
distance.
That's still a miss by a whisker on the cosmic scale and, says
Professor
Malcolm Walter of Macquarie University's department of
Astrobiology, we
can't always be that lucky.
Professor Malcolm Walter: It is not funny and as we said before,
it is going
to happen, it's just a matter of time.
John Collis: So science was well and truly on the case by the
tllywood
cashed in, offering harrowing insight with films like Deep
Impact.
And in that context of general growing awareness, an even more
baffling
mystery.
Dr Duncan Steel: We know how many are being missed and the answer
is that
most are being missed.
John Collis: We go back six years to the Siding Springs
Observatory scanning
the heavens from Coonabarabran in northwest New South Wales.
As the potential for global catastrophe dawned elsewhere,
Australia's own
Spaceguard program, led by Dr Duncan Steel, had already been on
finding and
charting intersecting asteroids for half a decade.
Abruptly and without explanation scuttled on the turn of the
political tide
in 1996 by the incoming Howard Government.
And to continuing bewilderment of expanding search programmes in
the
northern hemisphere, Spaceship Earth has been flying virtually
blind on the
southern aspect ever since.
Dr Duncan Steel: In essence, one third of the sky is not being
searched at
all.
John Collis: And no one is more puzzled by that than the man who
helped lay
the foundations.
Dr Duncan Steel: These things do happen, they don't happen often,
but when
they do they have catastrophic consequences and because of that
we have to
take them seriously, very seriously.
John Collis: It is now being taken seriously by many other
countries. There
is only one country in the world which has ever had a big
asteroid search
program and then closed it down - that's Australia.
Axed, it seems, for an annual saving of around 200,000 dollars,
paltry in
the context of the total Federal spend.
And after six years bouncing off the bureaucratic brick wall,
Michael Paine,
lobbying on behalf of the Planetary Society, still has no answer
for the
fundamental question: Why was funding cut?
Michael Paine, volunteer, Planetary Society: Here's all these
ministerial
portfolios, "it's not mine, it's not mine" and nobody
will come to grips
with it.
John Collis: What remains of the Australian effort is scattered
and almost
as elusive as the faint images marking a potential near-Earth
hazard.
Gordon Garradd, astronomer: Well I'm not going to save the Earth.
I'm just
going to help map out what's there and what the risk is. I'll
leave it to
others to work out what they are and what they are going to do
about it.
John Collis: On his private mountain in the New England Ranges of
northern
New South Wales, Gordon Garradd drives his home-made telescope
from the back
of his wagon.
A far cry from the mighty instrument he worked with Duncan Steel
at Siding
Springs but powerful enough to cover crucial gaps for NASA as
objects of
interest dip beyond range of northern observatories.
Gordon Garradd: The orbits do move around quite a lot so you have
got to
keep track of them otherwise they get lost and you don't know
where they are
and that's the main worry at the moment.
John Collis: One of just three part-timers retained by other
nations to keep
watch from Australia.
Dr Duncan Steel: It really is ridiculous. It is almost a Dad's
Army approach
to the defence of the world.
John Collis: Now back in Britain, Duncan Steel has his theories
about what
went wrong, favouring an astonishing conspiracy of political
ignorance and
professional skulduggery brought on by his own media profile.
Dr Duncan Steel: The problem is your fellow scientists. They get
so jealous,
they tell a pack of lies as happened in this case, which means
that in the
end your entire program gets cut.
John Collis: And when you look at the big picture of our
scientific
endeavour, the mystery only deepens because Australia is and long
has been
in the forefront of astronomical research.
This facility at Narrabri, for instance, is the most
sophisticated in the
southern hemisphere. And what was it doing when the latest threat
emerged
from space. It was doing the thing that interests big science:
peering at
objects at the known limits of the universe.
Professor Paul Davies: There are always two theories of history
of course,
aren't there. There's the conspiracy theory and the cock-up
theory. I always
favour the cock-up theory.
John Collis: A budgetary item too small to attract attention,
says Paul
Davies.
More practical than theoretical, more defence than science,
simply lost
somewhere in the "too hard basket".
But the failure to put things right richly deserving of
international scorn.
Professor Paul Davies: I think Australia's name is mud among the
people who
care about this particular issue.
John Collis: And, he says, even criminal.
Professor Paul Davies: If you stand back and say we are wilfully
ignoring
the greatest ecological threat to the planet, I'd say criminal.
Copyright 2002, Sunday Sunrise
===============
(3) THE THREAT ABOVE
>From 60 Minutes, 17 March, 2002
http://news.ninemsn.com.au/sixtyminutes/stories/2002_03_17/story_530.asp
Reporter: Liz Hayes Producers: Gareth Harvey, Sallie Stone
Join our live chat with Dr Duncan Steele and Michael Paine from
the
Planetary Society of Australian Volunteers on Sunday March 17 @
8:30-9.30pm
AEDST. Click here.
A few weeks ago, Liz Hayes visited the site of an asteroid strike
in Central
Australia. If a similar asteroid were to strike today, it'd be
curtains for
us all.
The scenario is more real than most of us realise. A third of all
asteroids
hitting earth's atmosphere do so over our southern skies.
So, imagine the fury of Australia's scientists when the Federal
Government
stopped funding "Spaceguard", a world's best program at
tracking asteroids.
The government claims there's nothing to worry about, but
scientists warn
it's left us blind to the threat from above.
TRANSCRIPT
LIZ HAYES: A few weeks ago, I visited the site of an ancient
asteroid strike
in central Australia. It's spectacular and very, very daunting.
If a similar
asteroid were to strike today, it would be curtains for us all.
So imagine
the fury of scientists when the Federal Government stopped
funding
Spaceguard, one of the world's leading programs tracking
asteroids. The
government says there's nothing to worry about, but scientists
warn this
leaves us blind to the threat.
STORY
LIZ HAYES: This is Hollywood's version of an asteroid slamming
into earth.
Scientists insist this is pure film-maker's fantasy. The reality
will be
far, far worse.
DR DUNCAN STEEL: Since the end of the Cold War, there's only one
thing left
which could cause a global catastrophe, which could wipe us all
out, or send
us back into the Dark Ages, and that's an asteroid hitting the
Earth.
BRIAN BOYLE: I don't know. Perhaps this is just nature's way of
giving us
the flick.
LIZ HAYES: Our planet is being stalked. The enemy is any one of
the
thousands of giant chunks of rock whose passage through space
could lead to
a collision with Earth.
DR DUNCAN STEEL: The reality is, right now as I sit here speaking
to you, I
know there are asteroids bigger than 50m or 60m in size which are
closer to
the Earth than the Moon.
LIZ HAYES: Astronomer Duncan Steel has dedicated his life to
hunting
asteroids. He says we're seriously ill-prepared for this threat
from space.
DR DUNCAN STEEL: You never know. It could be tomorrow. It could
be right now
as we're speaking that, in fact, one has entered the atmosphere
above
Sydney. And if a 50m or 60m rock enters above Sydney, everywhere
has had it.
LIZ HAYES: Asteroids can be as small as pebbles and as big as
planets. Their
numbers are infinite and they're hitting Earth all the time. Most
burn up in
the atmosphere, like this one filmed in the '70s. But the big
ones get
through. This is Wolf Creek Crater in WA. If I'd been standing
here 300,000
years ago, I would have seen what probably looked like a bright
shooting
star in the eastern sky. We now know it was a small asteroid,
travelling at
about 15km kilometres per second. It crossed over eastern
Australia in five
minutes. I would not have been alive to witness the final moments
of its
collision, but even today the scale of that impact is simply
breathtaking.
PAUL DAVIES: This crater here was blasted in the Australian
Outback by the
impact of an object about the size of a small office block and
flattened
everything in an area maybe up to 1000 square kilometres around,
so one hell
of a bang.
LIZ HAYES: Paul Davies is another Australian astro-biologist
trying to sound
the alarm.
PAUL DAVIES: This is just a lottery, these objects don't come on
cue. It's
totally random. There are many more smaller ones than big ones
and so
explosions of the magnitude that produced this crater here will
occur on
average perhaps every few hundred years.
LIZ HAYES: Paul Davies believes Australia is lucky that so far
asteroids
have only hit in the Outback. But more are coming. It's not a
matter of if,
but when.
PAUL DAVIES: Definitely when, because it's not going to stop now.
This
bombardment has been going on throughout geological history and
it's going
to continue.
DR DUNCAN STEEL: It is true that Australians on the average are
at greater
risk because we tend to live around the coast. If you live around
the coast,
you're facing on to big targets. The Indian Ocean, the Pacific
Ocean in
particular is a big target, and a decent asteroid going plonk
into the
middle of the Pacific is going to cause a tsunami which is going
to take
out, in essence, all of the cities along the east coast.
PAUL DAVIES: A tsunami rises up off the shore over there to
several hundred
metres. It would come straight across Sydney Heads, crashing
through the
harbour here, over the top of the Harbour Bridge - it would take
out that -
the whole CBD and then it would surge on into those suburbs
beyond. Millions
would perish, no doubt about that.
LIZ HAYES: And if an asteroid actually hit the city?
PAUL DAVIES: It would flatten the whole city with the blast wave
and it
would send a shock wave into the surrounding countryside and
cause damage
for tens of kilometres. If it were to explode in the air above
the ground,
as they often do, the devastation could be even worse.
LIZ HAYES: It has happened. Sixty-five million years ago, an
asteroid wiped
out nearly all life on earth. The impact and the aftermath left
dinosaurs
extinct.
DR DUNCAN STEEL: When we're talking about a decent-sized
asteroid, let's say
1km across, hitting the earth, you're talking about energy being
released
which is far in excess of all the world's nuclear arsenals put
together.
Quite clearly, something hitting the earth which kills millions,
perhaps
billions of people, is going to cause a total disintegration of
the society
which we currently know.
WOMAN: We have lift-off of the Delta rocket carrying the 'Nero'
spacecraft,
bound for the asteroid Eros.
LIZ HAYES: For the past decade, NASA has sent cameras into space
to learn
more about asteroids. Along with dozens of other countries,
America is
constantly searching and tracking asteroids. Last year, they even
landed on
an asteroid called Eros. These are the images they saw. But who
is watching
over the southern skies? Does Australia know what deep space is
throwing our
way?
DR DUNCAN STEEL: We believe there are something like 1200
asteroids bigger
than about 1km in size on Earth-crossing orbits - potential
impacters of the
Earth. We've found about half of them. The ones that are
dangerous to us at
the moment are those we haven't seen yet. People think we have
got all these
things mapped and that's the problem. That's what we keep saying.
We haven't
yet found all these objects. They think that there's these
batteries of
telescopes scouring the skies and there just aren't, you know. We
always say
there's less people working on looking for asteroids worldwide
than works in
the average McDonald's. That's the way it is.
LIZ HAYES: In 1996, the Howard government withdrew all money for
what was
known as Spaceguard, our part in the global response to the
asteroid menace.
But since then, despite repeated pleas by the international
scientific
community, the government has refused to renew the funding,
effectively
leaving us blind to what might be passing through the southern
skies. The
Spaceguard program, led by Duncan Steel, had identified 30
percent of known
asteroids. Steel now teaches in England and no-one is keeping
watch over
Australia.
DR DUNCAN STEEL: Australia in this area is a pariah. It's
regarded as being
a total outcast. It is the only country ever to have closed down
a
successful asteroid program when all the other countries are
gearing up.
PETER McGAURAN: I'm not going to be spooked or panicked into
spending scarce
research dollars on a fruitless attempt to predict the next
asteroid.
LIZ HAYES: Peter McGauran is the Minister for Science. He axed
the
Spaceguard program, taking Australia out of astronomy's version
of
Neighbourhood Watch.
PETER McGAURAN: We spend about $18 million a year on astronomy
and that's a
significant investment by Australia, particularly by worldwide
standards. I
wouldn't like to divert up to five or more percent of that budget
towards a
fruitless, unnecessary, self-indulgent exercise.
LIZ HAYES: Self-indulgent because scientists like Duncan Steel
think it
should be done?
PETER McGAURAN: How many others agree with them? I know they've
gathered
together a number of scientific generalists. I want the
astronomers
themselves, under the supervision of an objective worldwide
working party,
making a true and proper assessment. I'm just not convinced that
the hype
and alarm and even fear-mongering is enough to justify an instant
investment.
DR DUNCAN STEEL: A letter went to Mr Howard last week with 91
signatories,
in essence a roll call of all the world's experts in this area
saying,
"Please, we need Australia to be involved. You are the most
technologically
developed country in the Southern Hemisphere. We need you to be
involved in
this."
PETER McGAURAN: I lie awake worrying about a lot of other things.
Near-miss
asteroids is not one of them.
BRIAN BOYLE: Who are you going to get to guard the planet? A
bunch of
astronomers or a bunch of scientists? I don't think so. It is
clearly,
firmly, a Defence matter.
LIZ HAYES: Brian Boyle is Director of the Anglo Australian
Observatory in
Sydney. He says what's the point of tracking asteroids if there's
nothing
you can do to stop them?
BRIAN BOYLE: My colleagues are very well-intentioned and I have
the greatest
of respect for these people and they're right to identify it as
an issue,
but frankly, I think that a threat that exists without a credible
response
policy, as the asteroid threat indeed is, is not looking at the
full
picture. Please, don't lose any sleep. The asteroid is not
necessarily going
to come and get you tomorrow.
DR DUNCAN STEEL: The name of the game is: map all these objects
out there,
determine their orbits, mini-orbits, before they going to come
back and hit
the Earth, and then be able to say, "Hey, look, this one
here. That one's a
danger to us."
LIZ HAYES: And, says Steel, there are ways we can save ourselves
if we have
enough warning. Not quite Deep Impact, but using nuclear weapons
to deflect
an incoming asteroid well ahead of impact time.
DR DUNCAN STEEL: The dinosaurs did not have a space program.
That's why they
died. We need to have a space program in order to save ourselves
from the
next asteroid impact. It isn't a matter of if one of these things
is going
to hit the Earth. It's just a matter of when. Either we can
expect 23 years
warning or six or seven seconds. Okay. The most likely answer at
the current
time is six or seven seconds. We'll be aware of the asteroid
which is going
to hit us as it enters the atmosphere and all of a sudden lights
up far, far
brighter than the sun.
LIZ HAYES: And that would be it? That's it. You can kiss
everything goodbye.
© 1997-2001 ninemsn Pty Ltd - All rights reserved
=================
(4) ASTEROIDE PASSA DE RASPAO PELA TERRA
>From Globo.com, 16 March 2002
http://oglobo.globo.com/Ciencia/18305042.htm
Rio, 16 de Março de 2002
Asteróide passa de raspão pela Terra
LONDRES. Um asteróide grande o suficiente para destruir cidades
passou perto
da Terra na semana passada, mas só foi detectado depois que já
se afastava
do planeta. O incidente reacendeu a discussão sobre a
necessidade de
melhorar o sistema de rastreamento de asteróides e cometas
potencialmente
perigosos.
O asteróide, batizado de 2002 EM7, passou a 450 mil quilômetros
do planeta -
o equivalente a uma vez e meia a distância da Terra à Lua - no
último dia 8.
Só foi notado por astrônomos quatro dias depois. O astro estava
no ponto de
sua órbita mais próximo do Sol, a 87 mil quilômetros apenas, e
a
interferência da luz solar impedia que ele fosse visto da Terra.
Asteróides que se aproximam por esse ponto cego não podem ser
vistos pelos
astrônomos. Se um objeto desconhecido passar por essa zona em
rota de
colisão com a Terra, não seria identificado a tempo de se
lançar um alerta.
Nos últimos anos, os cientistas já fizeram numerosos pedidos de
verbas para
que consigam catalogar astros próximos à Terra e detalhar suas
órbitas.
Invisível a olho nu, o asteróide tem entre 50 e cem metros -
maior do que o
astro que caiu, em 1908, na Sibéria, derrubando árvores numa
área de cerca
de 2.000 quilômetros quadrados.
===============
(5) AMATEUR ASTRONOMER DETECTS NEAR EARTH ASTEROID
>From Der Spiegel, 15 March 2002
http://www.spiegel.de/wissenschaft/weltraum/0,1518,187243,00.html
Hobby-Astronom entdeckt erdnahen Asteroiden
Ein Essener Freizeitforscher hat einen Kleinplaneten entdeckt,
der als
potenziell gefährlich eingestuft wurde. Groß ist das Risiko
eines
Zusammenpralls aber nicht.
Der Asteroid, der die Bezeichnung 2002 EL6 erhielt, kreuzt die
Bahn der
Erde. Nach Angaben der US-Raumfahrtbehörde Nasa liegt die
Wahrscheinlichkeit
einer Kollision in diesem Jahrhundert jedoch nur bei etwa eins zu
30
Millionen. Das Minor Planet Center, ein Erfassungsprogramm für
Kleinplaneten
am Smithsonian Astrophysical Observatory, listet derzeit 386
solcher
Asteroiden auf potenziell gefährlichen Bahnen auf.
Der Essener Amateur-Astronom entdeckte 2002 EL6 am 11. März als
Gastbeobachter an der Sternwarte Drebach in Sachsen. Das Minor
Planet Center
habe den Kleinplaneten anschließend als potenziell gefährlich
eingestuft,
teilte die Sternwarte Bochum am Freitag mit.
Copyright 2002, Der Spiegel
=================
(6) RADAR REVEALS BIG SPLASH ON MERCURY
>From Sky & Telescope, 15 March 2002
http://skyandtelescope.com/news/current/article_536_1.asp
By J. Kelly Beatty
March 15, 2002 | During the mid-1970s, fortuitous geometry
allowed Mariner
10 to zip by Mercury three times in a 12-month period. But that
same
geometry precluded the spacecraft from seeing almost half of the
innermost
planet's surface - a "terra incognita" that remains
virtually unknown nearly
three decades later.
However, as radar facilities on Earth continue to probe the
unseen territory
with ever-improving resolution, Mercury is slowly giving up its
secrets.
Several days of observations made last June and July with the
305-meter
Arecibo dish in Puerto Rico recorded details only a few
kilometers across
and turned up a number of surprises.
Nearly straddling the equator on Mercury's unseen hemisphere is a
prominent,
85-kilometer-wide crater sitting in a splash of bright rays some
900 km
across. According to John K. Harmon (National Astronomy and
Ionosphere
Center) and Donald B. Campbell (Cornell), the rays are extremely
rough -
jumbles of rock and dust thrown out by the impact - which makes
them
excellent reflectors of Arecibo's radar pulses. The rays look so
fresh, in
fact, that this crater may be much younger than similarly sized
Tycho, which
was blasted out of the lunar landscape 109 million years ago.
Harmon notes
that the unnamed Mercurian crater had been seen in previous radar
campaigns,
but with only a tenth as much resolution.
Fortunately, two new spacecraft will soon be en route to
mysterious Mercury.
NASA's mission, MESSENGER, calls for a heavily instrumented craft
to slip
into orbit around the planet in April 2009 and conduct
comprehensive mapping
surveys and compositional assays. That same year the European
Space Agency
plans to dispatch its BepiColombo spacecraft, which honors
Italian space
scientist Guiseppe "Bepi" Colombo (1920-1984). Upon
arrival at Mercury after
a 2½-year flight, it will separate into one orbiter to study the
globe, a
second orbiter to monitor the magnetic field, and a small lander
to analyze
the surface rocks.
Copyright 2002 Sky Publishing Corp.
=============
(7) AMATEUR ASTRONOMER DISCOVERS NEW COMET
>From Ron Baalke < baalke@jpl.nasa.gov
>
http://www.svherald.com/archives/index.inn?loc=detail&doc=/2002/March/14-3507-news1.txt
Stargazer finds comet
BY LYN SOUTHERLAND
Sierra Vista Herald
March 14, 2002
PALOMINAS - With his eyes on the skies and the strains of
"Some Enchanted
Evening" playing in the background, Doug Snyder made the
discovery of a
lifetime early Monday morning.
The amateur stargazer discovered a new comet streaking through
the Aquila
Constellation in the heart of the Summer Milky Way galaxy.
At 3:40 on Monday morning, he happened across "a little gray
smudge" nestled
in the Aquila Constellation. He did some quick research using a
sky atlas
and numerous databases, but couldn't locate any references to his
find.
Trying not to get his hopes too high, Snyder checked the comet's
location
again. "The comet had moved a bit, but not too much, and I
found it again
fairly easily. Dawn was coming, and my view of the comet was
fading, but by
now I was becoming more sure of my discovery," Snyder said.
He immediately e-mailed news of his discovery to the Central
Bureau for
Astronomical Telegrams, the Harvard-affiliated clearinghouse for
new
discoveries. It was 4 a.m. and the world was being told the
latest space
find had been made at a small observatory in Southeastern
Arizona.
Several anxious hours later, he received a reply. CBAT has spent
the interim
time researching his find, verifying Snyder's experience and
credentials,
and locating the comet. CBAT asked for additional information,
which Snyder
provided, and then he waited.
"It's been a whirlwind couple of days," Snyder said.
"But yesterday
(Tuesday), they finally let me know that I had really discovered
a new
comet."
Full story here:
http://www.svherald.com/archives/index.inn?loc=detail&doc=/2002/March/14-3507-news1.txt
============
(8) MANITOBA METEORITE SECOND LARGEST DISCOVERED IN CANADA
>From Andrew Yee < ayee@nova.astro.utoronto.ca
>
Marketing & Communications
University of Calgary
Calgary, Alberta
Contact:
Dennis Urquhart, Media Relations
(403) 220-7722
March 5, 2002
8.2-kilogram Manitoba meteorite is second largest of its kind in
Canada
A large rock that a Manitoba man found while grading a road has
been
identified as Canada's newest meteorite by the Prairie Meteorite
Search, a
national project led by the Universities of Calgary, Regina, and
Western
Ontario.
The Elm Creek meteorite, weighing 8.2 kilograms, is the
second-largest stony
meteorite ever found in Canada and is Manitoba's largest. It is
the fifth
meteorite to be recovered in Manitoba (Manitoba is now tied with
Quebec for
recoveries), and is the 61st Canadian discovery. It is also the
first time
that a meteorite has been found in Canada with a road grader.
Tom Wood (right) unearthed the big rock while grading a dirt road
to the
southeast of Elm Creek, Manitoba during late August 1997.
"It seemed to be
too heavy to be a normal stone," Wood recalls. "I
thought then that it might
be a meteorite, but I was half kidding when I told my wife so
later that
day."
The recovered stone is a broken piece with scrape marks on it,
presumably
from road grading. The other half of the meteorite, estimated to
weigh about
five kilograms, is thought to be still embedded in the dirt road.
Mr. Wood is not sure
exactly where he recovered the first piece, so the recovery of
the remainder is in doubt.
Dan Lockwood, a U of C student, was the Prairie Meteorite
Searcher for the
summer of 2001. The Elm Creek meteorite was his second discovery
among about
600 samples of possible meteorites that he looked at. He was
holding a rock
identification clinic in the Co-op store in Carman, Manitoba,
when Mr. Wood brought
the rock in.
"The rock was covered in dirt, but its density made it
deserving of a wash
and a closer look," Lockwood (left) says. "After
washing I had suspicions
that the rock was indeed a meteorite, but I flip-flopped back and
forth for
more than three weeks over whether or not it was genuine."
The meteorite was eventually confirmed when Lockwood returned to
the
University of Calgary at the end of his field season. It is a
well-weathered
rock and probably fell to Earth thousands of years ago. Most of
its fusion
crust is weathered off revealing an interior that shows cracks
from the
shattering of its parent asteroid.
Dr. Alan Hildebrand, holder of a Canada Research Chair in
Planetary Sciences
at the U of C and one of the project leaders, praises Mr. Wood
for his
efforts in bringing the specimen to the attention of scientists.
"I am
frankly amazed at Mr. Wood's perceptiveness in noting that this
dirt-covered
rock was unusual. It goes to show what a lifetime of experience
and healthy
curiosity can do to one's perceptions," Hildebrand says.
Research will help
classify the stone and determine if it was part of a larger fall.
The Prairie Meteorite Search field campaign locates meteorites by
encouraging Prairie farmers to have rocks identified that they
suspect may
be meteorites. The project consists of local publicity and visits
by the
searcher to towns to show meteorite specimens and to identify
possible
meteorites. The project relies on people having seen meteorites
and the
possibility of immediate identification to make discoveries.
"More than a dozen unconfirmed new meteorites are thought to
be in the hands
of farming families across the prairies," says Lockwood, who
is now back
studying at the University of Calgary. "The Prairie
Meteorite Search found
two new meteorites during each of the summers of 2000 and 2001,
but a better
means of reaching farmers who have rocks to be identified should
be able to
increase the recovery rate."
The Prairie Meteorite Search project leaders are Dr. Alan
Hildebrand,
University of Calgary; Dr. Peter Brown, The University of Western
Ontario,
and Dr. Martin Beech, University of Regina. They are all members
of the
Meteorites and Impacts Advisory Committee to the Canadian Space
Agency. This
is Canada's volunteer group charged with the investigation of
fireballs and
the recovery of meteorites. Project funding for the summer
project of 2001
came from the Natural Sciences and Engineering Research Council's
Undergraduate Student Research Award Program, the international
Meteoritical
Society, and other grants held by the project leaders.
Potential meteorites may be identified by contacting:
* in Manitoba -- George Clark at Dept. of Geological Sciences,
University of Manitoba (204) 474-8857
* in Saskatchewan -- Martin Beech at Campion College, University
of
Regina (306) 359-1216.
* in Alberta -- Alan Hildebrand at Dept. of Geology and
Geophysics,
University of Calgary, (403) 220-2291.
Additional contact information for the project is located at this
Web
address: http://www.geo.ucalgary.ca/PMSearch/
For Media:
Mr. Tom Wood may be contacted at (204) 745-7132 at (204)
436-2332.
Dan Lockwood can be reached via Alan Hildebrand at (403) 220-2291
or Dennis
Urquhart (403) 220-7722.
High-resolution images of Mr. Wood and/or Dan Lockwood can be
obtained from
Dennis Urquhart at (403) 220-7722 or durquhar@ucalgary.ca
[NOTE: Images supporting this release are available at
http://www.fp.ucalgary.ca/unicomm/news/March_02/meteorite.htm
]
============================
* LETTERS TO THE MODERATOR *
============================
(9) REGIONAL K/T EXTINCTION & TERTIARY DISPERSAL OF SURVIVORS
>From Hermann Burchard < burchar@mail.math.okstate.edu
>
Dear Benny,
the journal SCIENCE, March 15, has an article "Mammalian
Dispersal at the
Paleocene/Eocene Boundary", dispersal being shown by the
authors to have
proceeded out of Asia into North America and Europe. (See copy of
abstract
below.)
http://www.sciencemag.org/cgi/content/abstract/295/5562/2062
Is this not evidence for regional extinction at the K/T boundary?
After one
or more cosmogenic impacts, survivors likely remained in areas
that were the
most remote from impact sites. Mention is made in the abstract of
primates
(not of Africa). Evidence for primates in Africa before 25 Ma
ago, when
Africa-Arabia collided with Asia does not seem very strong (the
full article
may cover these points).
Another SCIENCE article earlier this month could be said to have
lent
support to the regional extinction idea: "Flight of the
Dodo." Beth
Shapiro, Dean Sibthorpe, Andrew Rambaut, Jeremy Austin, Graham M.
Wragg,
Olaf R. P. Bininda- Emonds, Patricia L. M. Lee, and Alan Cooper.
Science
Mar 1 2002: 1683. This was widely reported in media, e.g.:
http://www.iht.com/articles/51210.html
The flightless Dodo, as is shown there from DNA analysis, was a
pigeon
standing three feet tall that became isolated genetically after
flying to
the Mascarene group of islands, to which Maurititius belongs
about 42 Ma ago
at the end of the Eocene. Its nearest relatives today live in SE
Asia and
Australasia, ranging from the Nicobars to Samoa.
Of course, from plate tectonics we know that Mauritius at 42 Ma
would have
been nearer to where the Seychelles are now, and both were closer
to India,
which then had just begun to collide with the main continent of
Asia.
Rifting along the Carlsberg Ridge continues to cause seafloor
spreading.
Australasia and the Nicobars, too, would have been closer to
Mauritius at
that time.
There would seem to be more evidence here for regional extinction
and
subsequent dispersal of birds as well as mammals from areas far
from K/T
impact sites in the Yucatan (Chicxulub crater, widely accepted)
and Bombay-
Seychelles-Amirante (Shiva crater, controversial). The latter
split the
Earth's crust along the Carlsberg Ridge and left the Reunion
Island volcano
near Mauritius.
Those ancestral pigeons flew into the devastated lands around the
Shiva
crater perhaps being among the first colonists, growing
genetically isolated
from their Eastern cousins some 23 Ma after the impacts.
Recently, K/T gradualism was discussed by Jan Smit and Gerta
Keller, CCNet
February 1, 2. I rather suspect this may be a case of possible
multiple
impacts at time intervals alleged to be millions of years causing
regional
extinctions. Any actual gradualism (as opposed to multiple
impacts and
regionalism) I believe was disproved by Peter Sheehan, Milwaukee,
whose
teams carefully surveyed the abundance of dinosaurs in the
uppermost
Cretaceous strata of South Dakota and Montana, finding
Tyrannosaur and
Triceratops up to the very extinction layer. To me, this looks
like sudden
extinction of these key Cretaceous genera (I don't think he
deserves the
criticism that he has received from some quarters).
Regionally some dinosaurs survived --! After all, birds were
dinosaurs of a
sort, as we know from Mongolian feather-clad non-avian dinosaurs
found
recently. We can picture a feathered T. rex, flapping stubby
wings darting
about for morsels much like birds do, but incapable of a
sustained run.
Best regards,
Hermann
-------------
Mammalian Dispersal at the Paleocene/Eocene Boundary
Gabriel J. Bowen,1* William C. Clyde,2 Paul L. Koch,1 Suyin
Ting,34 John
Alroy,5 Takehisa Tsubamoto,6 Yuanqing Wang,4 Yuan Wang4
A profound faunal reorganization occurred near the
Paleocene/Eocene
boundary, when several groups of mammals abruptly appeared on the
Holarctic
continents. To test the hypothesis that this event featured the
dispersal of
groups from Asia to North America and Europe, we used isotope
stratigraphy,
magnetostratigraphy, and quantitative biochronology to constrain
the
relative age of important Asian faunas. The extinct family
Hyaenodontidae
appeared in Asia before it did so in North America, and the
modern orders
Primates, Artiodactyla, and Perissodactyla first appeared in
Asia at or before the Paleocene/Eocene boundary. These results
are
consistent with Asia being a center for early mammalian
origination.
1 Department of Earth Sciences, University of California, Santa
Cruz, CA
95064, USA.
2 Department of Earth Sciences, University of New Hampshire,
Durham, NH
03824-3589, USA.
3 Museum of Natural Science, Louisiana State University, Baton
Rouge, LA
70803, USA.
4 Institute of Vertebrate Paleontology and Paleoanthropology,
Chinese
Academy of Sciences, Post Office Box 643, Beijing 100044,
People's Republic
of China.
5 National Center for Ecological Analysis and Synthesis,
University of
California, Santa Barbara, CA 93101-3351, USA.
6 Primate Research Institute, Kyoto University, Inuyama 484-8506,
Japan.
* To whom correspondence should be addressed. E-mail: gbowen@es.ucsc.edu
=============
(10) AND FINALLY: NASA STUDY FAVOURS 'POWER NAP' AT WORK
>From Ananova, 18 March 2002
http://www.ananova.com/news/story/sm_547001.html?menu=news.scienceanddiscovery
Nasa researchers say company bosses should allow their workers to
fall
asleep at their desks.
Studies have shown that performance increases by 35% if employees
take a
45-minute "power nap" in the afternoon.
Scientists says the Mediterranean-style siesta should be adopted
by any
business looking to increase its productivity.
The nap even improves the ability to judge business decisions
correctly by
50%, it's claimed.
Nasa carried out the research to find out how best to make use of
astronauts' time in space.
But they also found the same was true for office workers with
less glamorous
or demanding jobs.
Mark Rosekind, of California-based Alertness Solutions, told The
Times: "It
is a false myth that if you spend more hours awake you are more
productive."
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