PLEASE NOTE:
*
CCNet 103/2003 - 11 November 2003
THE 2003 LEONID METEOR SHOWER
------------------------------------------------
Across Britain, more than 40 million people - in airports and
buses, in law
courts and football clubs, at railway stations and banks, radio
and television
stations, in superstores, schools and universities and those at
home are expected
to fall silent for two minutes at 11am on Armistice Day, Tuesday
11th November.
The Two Minute Silence marks the moment the guns fell silent at
the end of the
First World War - the eleventh hour of the eleventh day of the
eleventh month in
1918. It is a moment to remember all those who have given their
lives for freedom and
democracy in the conflicts of the last century and in the early
years of this
new millennium.
(1) THE 2003 LEONID METEOR SHOWER
Science@NASA
(2) 2003 LEONID PREDICTIONS
Rainer Arlt <rarlt@aip.de>
(3) "LOOKING OUT FOR YOU": PATENTING A NEO DETECTION
SYSTEM
Houston Chronicle, 10 November 2003
(4) MISSION COULD SHED LIGHT ON HOW MOON WAS FORMED
St Louis Post-Dispatch, 7 November 2003
(5) EXPERTS SEEK TRAIL TO MARK ICE AGE FLOODS
Newsday, 10 November 2003
(6) SCIENTISTS HOPE TO GET MORE ACCURATE EARTH AND CLIMATE
HISTORY
The State, 10 November 2003
(7) AND FINALLY: WHILE U.S. AND CHINA ARE BOOMING, EUROPE CUTS
BACK LONG-TERM SPACE PROGRAMME
Space Daily, 8 November 2003
==============
(1) THE 2003 LEONID METEOR SHOWER
Science@NASA
http://science.nasa.gov/headlines/y2003/10oct_doubleleonids.htm
An unusual double Leonid meteor shower is going to peak next
month over parts of Asia and North America.
October 10, 2003: The Leonid meteor shower is coming. Twice.
Bill Cooke of the Space Environments Group at the NASA Marshall
Space Flight Center explains:
"Normally there's just one Leonid meteor shower each year,
but this year we're going to have
two: one on Nov. 13th and another on Nov. 19th."
Both are caused by comet Tempel-Tuttle, which swings through the
inner solar system every 33
years. With each visit the comet leaves behind a trail of dusty
debris--the stuff of meteor
showers. Lots of the comet's old dusty trails litter the
mid-November part of Earth's orbit.
"Our planet glides through the debris zone every year,"
says Cooke. "It's like a minefield.
Sometimes we hit a dust trail, sometimes we don't." Direct
hits can spark a meteor storm,
which is defined as more than 1000 shooting stars per hour.
"That's what happened in, for
example, 1966 and 2001," says Cooke. "Those were great
years for Leonids."
"This year we're going to brush past two of the trails--no
direct hits," he says. Even so,
"we might have a nice display."
The first shower is expected on Nov. 13th around 17:17 UT. For
about three hours centered on
that time Earth will be close to some dust shed by Tempel-Tuttle
in the year 1499. Sky watchers
in Alaska, Hawaii and along the Pacific rim of Asia are favored.
They'll see anywhere from a
few to 40 meteors per hour--"if they can avoid the glare
from that night's gibbous Moon,"
cautions Cooke. A good strategy for moonlit meteor observing:
travel to high altitudes where
the air is clear or stand in the shade of a tall building or
hillside.
Curiously, the Moon will be much closer to the 1499 trail than
Earth will be. "If the Moon had
an atmosphere to catch the comet dust, there would be about 1400
meteors per hour in lunar
skies--a real storm," notes Cooke. Instead, the Leonids will
simply hit the ground.
Most Leonid meteoroids are microscopic, and when they hit the
Moon they do little more than
raise a puff of moon dust. But a few will be bigger: the size of
golf balls or grapefruits.
Traveling about 160,000 mph, these impactors can cause explosions
visible from Earth. (For more
information about this, read the Science@NASA
story Explosions on the Moon.)
"This year we won't be able to see any lunar impacts,"
notes Cooke, "because most of the Leonids
will strike the far side of the Moon. Some will hit the
Earth-facing side, but the ground where
they hit will be sunlit. That makes it very hard to see the
explosions."
The second and more impressive shower arrives almost a week later
on Nov. 19th when Earth
approaches a trail shed in 1533. "Sky watchers up and down
the US east coast will have the
best view," says Cooke. "For a while around 07:28 UT
(2:28 a.m. EST), they could see more
than one meteor per minute." The Moon, a thin crescent on
Nov. 19th, won't be bright enough
to interfere with the display. (Nor will it be close to the
cometary dust stream, so once
again there will be no visible lunar explosions.)
Cooke assembled these forecasts using data from several
researchers who have done a good job
predicting Leonid storms in recent years: Peter Jenniskens at
NASA's Ames Research Center,
Jeremie Vaubaillon of the Institut de Mecanique Celeste et de
Calcul des Ephemerides in France,
and Esko Lyytinen. They mostly agree that Earth will encounter
dust streams on Nov. 13th and
19th, but there is less consensus about how intense the resulting
showers will be. Lyytinen, for
instance, predicts a maximum of just 30 meteors per hour on
Nov. 19th. Vaubaillon says 100.
Who's right? See for yourself. Be outside when the time comes,
looking up.
==============
(2) 2003 LEONID PREDICTIONS
Rainer Arlt <rarlt@aip.de>
Dear Benny,
There was a Leonid meteor announcement in the CCNet today.
A compilation of Leonid model predictions is now published
by Vaubaillon, Lyytinen, Nissinen and Asher. The editorial
board of WGN, the Journal of the Int. Meteor Org. has agreed
to put the article online immediately. I am appending the
announcement with the key table of that paper below. The
information might be useful for CCNet readers.
Best regards,
Rainer
Leonid predictions published in WGN, Journal of the IMO
=======================================================
An article by J. Vaubaillon, E. Lyytinen, M. Nissinen, and D.J.
Asher
is now in press for the October issue of WGN, vol. 31. The paper
is
already available at
http://www.imo.net/
or on the mirror site
http://www.amsmeteors.org/imo-mirror/
The authors' compilation of 2003 Leonid models is given below.
Larger
values of Da_0 correspond to fainter meteors. f_M measures the
extent
to which a trail has stretched in the along-orbit direction being
1.0
for a 1-revolution trail and closer to zero for more stretched
trail
sections. Negative values of f_M occur when the order of
meteoroids
is reversed due to planetary perturbations. ZHR is the measure
for
visual hourly meteor rates with the radiant in the zenith and a
stel-
lar limiting magnitude of +6.5.
----------------------------------------------------------------------
Trail
Model
Da_0 f_M Time
UT
ZHR
----------------------------------------------------------------------
1499 Asher&McNaught 0.28
~0.03 Nov 13,
13h15
-
1499 Asher&McNaught 0.26
~0.8 Nov 13,
18h20
-
1499
Lyytinen 0.28
~1.6 Nov 13, 16h40 half a day 100
1499
Vaubaillon
Nov 13,
17h17
120
----------------------------------------------------------------------
1533 Asher&McNaught 0.30
-0.04 Nov 19,
06h30
-
1533
Lyytinen 0.30
~0.1 Nov 19,
08h
dozen(s)
1533
Vaubaillon
Nov 19,
07h28
100
----------------------------------------------------------------------
1333 Asher&McNaught 0.12
~0.02 Nov 20,
00h50
-
1333
Lyytinen
~0.02 Nov 20,
01h30
20
1333
Vaubaillon
Nov 20,
01h26
15
----------------------------------------------------------------------
736
Lyytinen
-0.008 Nov 22,
21h
10
736
Vaubaillon
Nov 22,
22h02
2
----------------------------------------------------------------------
636
Vaubaillon
Nov 23,
02h56
10
----------------------------------------------------------------------
1733
Lyytinen
0.11 Nov
19, 00h25 a few dozen?
----------------------------------------------------------------------
On behalf of the editorial board of WGN,
Rainer Arlt
--
Rainer Arlt -- Astrophysikalisches Institut Potsdam
-- www.aip.de
Visual Commission - International Meteor Organization -- www.imo.net
rarlt@aip.de -- phone:
+49-331-7499-354 -- fax: +49-331-7499-526
=============
(3) "LOOKING OUT FOR YOU": PATENTING A NEO DETECTION
SYSTEM
Houston Chronicle, 10 November 2003
http://www.chron.com/cs/CDA/ssistory.mpl/space/2214427
By MARTHA McKAY
HACKENSACK, N.J. -- Just last month, a meteorite slammed into a
village in eastern India.
Eleven people were injured and two homes were destroyed by fire.
Perhaps more unsettling, in 1908, a space rock screamed into
Earth's atmosphere, exploding in
the sky over a remote Siberian forest with a force greater than a
10-megaton nuclear blast.
Fires started, wildlife perished and trees fell for miles in
every direction.
These days, efforts under way to detect comets and asteroids on a
potential collision course
with Earth include an unassuming scientist from Ridgewood, N.J.,
with an idea for a better
method.
William Hoffman doesn't have a company, or investors for his
detection system, called "Looking
out for you." But he received a patent (U.S. No. 6,452,538),
and some distinguished astronomers
say his idea is intriguing.
Hoffman wants to place telescopes on the outer-space side of
telecommunications satellites
where they can continuously scan the heavens, free from cloud
cover that often hampers
earthbound telescopes, to look for what astronomers call NEOs, or
Near Earth Objects.
The data would beam down to a ground station and be sent -- for a
fee -- to schools or
institutions or individuals who could use it to pinpoint the
rocks' orbit.
"I can't speak for NASA, but personally I think it's a great
idea if he can make it work," said
Dan Mazenek, an aerospace engineer based at NASA's Langley
Research Center and director of
a study on how best to search for large comets and asteroids that
might strike Earth.
"If he can get the money to put telescopes up there, then
I'm interested in the results," said
Lucy McFadden, a University of Maryland astronomer and a director
of NASA's Dawn Discovery
Mission.
McFadden was one of 13 scientists and researchers who signed an
open letter to Congress in July
warning of the threat from space and urging the government to
invest in some kind of system
to help guard against a significant hit.
"There are lots and lots of people that would buy into the
idea of helping protect the Earth
by signing onto a program like this," said Kelly Beatty,
executive editor of Sky & Telescope
magazine. Whether they would pay for the privilege is another
question, he added.
Copyright 2003 The (Hackensack) Record
==========
(4) MISSION COULD SHED LIGHT ON HOW MOON WAS FORMED
St Louis Post-Dispatch, 7 November 2003
http://www.stltoday.com/stltoday/news/stories.nsf/News/47A57F9826F24CBE86256DD8001917C6?OpenDocument&Headline=Mission+could+shed+some+light+on+how+the+moon+was+formed
Mission could shed some light on how the moon was formed
By ELI KINTISCH
Lunar craters have given us tantalizing bits of information.
Scientists hope a mission proposed for 2009 can tell us more.
Looking forward to the lunar eclipse tonight? The real show was 4
billion years ago.
Back then, volleys of meteoroids, many dozens of miles wide,
bombarded the young moon. The energy blasted holes miles deep
into the lunar landscape and flung boulders into space. Some
impacts shook the entire moon with their force, said lunar
geochemist Randy Korotev of Washington University.
"I often think I wish I could have been there to see
it," said Korotev. "But I don't know where I'd
stand."
Lunar craters are some of our best clues about the Earth's first
half billion years. Our planet took a similar beating back then,
but the evidence has been erased by plate tectonics and weather.
Missions to the moon have delivered clues about the era, but
debate rages over how the nascent days of the solar system
looked. Now three Washington University scientists are helping
propose an unmanned mission in 2009 to the dark side of the moon,
as it's known colloquially, to learn more.
Craters on the near side of the moon, where the Apollo astronauts
explored, have their own secrets. Among other things, analysis of
moon rocks has suggested that the moon formed in less than a
million years, and led scientists to theorize the existence of a
hot moon sea.
One giant crater, known as Imbrium, is especially enigmatic. That
crater was formed by a rocky meteoroid about 40 miles across,
said Washington University chemist Larry A. Haskin. The meteoroid
blasted rock out from more than 4 miles deep inside when it hit.
In 1998 a NASA spacecraft called the Lunar Prospector scanned the
moon's surface and found relatively high amounts of a trace
element called thorium concentrated in rocks in the general area
of Imbrium.
Moon rocks brought back from that area by Apollo astronauts had
shown high concentrations of thorium, so scientists had
mistakenly theorized that these elements were evenly distributed
in a layer deep within the moon. As meteoroids punched into the
moon's interior, the theory went, the thorium was blasted out
onto the surface.
Yet the moon surface is pockmarked with craters. If the thorium
was in fact evenly distributed, Lunar Prospector would have
detected it all over the moon.
The fact that the thorium was found on only one side raises
intriguing questions. Were "tides," as Haskin called
them, pulling the thorium on a sea of melted rock toward the
Earth?
"Nobody knows yet," said Haskin, who has been studying
the Imbrium crater for years with Korotev and Washington
University planetary geologist Bradley L. Jolliff. The three are
now trying to answer another question: Was the Imbrium impact
simply the last of a long line of impacts, or was it part of a
sustained barrage that scientists call the "cataclysm"?
The answer may lie on the moon's far side. NASA recently
determined that a mission to take rock samples from a crater
there would be one of four candidates for a 2009 unmanned effort.
The trio here is helping develop a proposal for the endeavor.
If rocks from that side of the moon are the same age as the
samples taken near Imbrium - roughly 3.9 billion years old - that
could mean the cataclysm was real.
And that, in turn, would rewrite the early history of our solar
system.
Copyright 2003, St Louis Post-Dispatch
=========
(5) EXPERTS SEEK TRAIL TO MARK ICE AGE FLOODS
Newsday, 10 November 2003
http://www.newsday.com/news/science/wire/sns-ap-exp-ice-age-floods,0,3409451.story?coll=sns-ap-science-headlines
By JOSEPH B. FRAZIER
Associated Press Writer
THE DALLES, Ore. -- The National Park Service has proposed a
marked trail to commemorate Ice Age floods through four Western
states that left canyons, valleys, lakes and ridges that still
dominate the terrain today -- some so dramatic they can be seen
from outer space.
Picture an ice dam 30 miles wide, forming a lake 2,000 feet deep
and 200 miles long, stretching from the Idaho panhandle into
western Montana, containing more water than Lake Erie and Lake
Ontario combined.
Now picture that dam giving way, the water thundering out in 48
hours, through four states, across Washington and into the
Pacific.
These cataclysmic events, called the Missoula Floods, took place
at the end of the last Ice Age, 14,000 years ago -- the biggest
scientifically documented floods ever.
Yet no marked trail commemorates the floods' path or explains
their significance to the public. A growing number of amateur and
professional geologists fascinated by the floods think that's a
shame, and a Park Service study has proposed a remedy.
The study, issued in 2001, suggests an Ice Age Floods National
Geographic Trail that would follow the 600-mile path of the
flood, mostly along existing highways, with signs highlighting
important features.
The interpretive flood pathway would cross four states as part of
the national park system, recognizing the floods and the 16,000
square miles they covered as a nationally significant resource.
Some markers already exist along the floods' trail, but they were
placed by a variety of organizations and are hit and miss,
according to Jim O'Connor, a geologist with the U.S. Geological
Survey.
The Park Service study envisions a comprehensive route, with
towns near key flood features as "gateway communities."
Hiking and horse trails, canoeing and kayaking routes would help
visitors realize the scope of what happened. The study also
recommends that no private land be taken for the project.
The Ice Age Flood Institute, a private nonprofit group that
educates the public about the floods, would also like to see
visitors' centers on the trail.
But while funding for the Park Service study came from Congress,
Congress has not followed up.
"No bill has been introduced yet," said Dale Middleton
of Seattle, president of the flood institute, which met Oct. 11
to discuss the project. "We are trying to get someone in the
Northwest congressional delegation to do so."
Evidence of the floods are everywhere. They hit the Columbia
River near present-day Wenatchee, Wash., probably swelling the
river to 4,000 times its present-day flow and spilling over the
Columbia River Gorge.
The gorge, 80 miles long and up to 4,000 feet deep, couldn't
contain the water, which scoured the rock walls clean and spilled
over, probably widening the gorge.
Geologists compare the gorge to a nozzle that sent the floods
pouring out in a wall of water perhaps 500 feet high at 80 mph,
putting Oregon's Willamette Valley under 400 feet of water as far
south as the Eugene area and present-day Portland.
"Most of Portland is a big sand and debris bar deposited
where the flood slowed down as it spread out over the Portland
Basin," said O'Connor, who is with the USGS Portland office
and has researched the floods extensively.
Willamette Valley's fertile soil -- which attracted settlers from
the Oregon Trail -- comes from deposits of flood silt that reach
100 feet deep in places.
"The Oregon Trail might have gone somewhere else if the
floods hadn't filled the valley full of sand and silt," he
said.
Residents of Portland's comfortable Alameda Ridge and posh Lake
Oswego still curse as they tussle with boulders on their
property, unaware that they may have ridden the floods for 500
miles encased in icebergs.
The Willamette Meteorite, at nearly 16 tons the largest ever
found in the United States and the sixth-largest in the world,
apparently also rode the flow. It was identified near West Linn
south of Portland in 1902 and is on display at the American
Museum of Natural History in New York City.
Flood deposits 50 feet thick in the Beaverton area west of
Portland are considered a factor in the area's vulnerability to
earthquakes.
In what is now eastern Washington, water flooded today's Spokane
Valley to a depth of about 500 feet. The floods ripped away
bedrock and formed deep canyons, or "coulees," which
remain. Erosion and washed-out channels are visible from space.
Some scientists say they curiously resemble those on Mars.
O'Connor said it is not clear whether the floods hit inhabited
regions.
Scientists also believe that the Missoula Floods occurred
repeatedly over the course of about 2,500 years, as new glacial
ice dams plugged the river outlet, Glacial Lake Missoula refilled
with water, and the dam then ruptured once again.
University of Montana geology professor David Alt, author of
"Glacial Lake Missoula and its Humongous Floods," says
the lake broke through ice dams and refilled at least 36 times,
probably averaging once every 50 years.
U.S. Geological Survey experts have estimated the flow near the
dam breach at 10 times more than the combined flow of all the
rivers in the world.
But scientists have often disagreed over the floods' size, scope
and frequency. Some have been pilloried for what they thought,
none more than J Harlen Bretz, a geologist who worked at the
University of Chicago and did extensive field work on the floods.
In 1923 he came up with the theory of a catastrophic flood that
deluged the landscape over a matter of days. According to Alt,
Bretz's theory contradicted prevailing scientific thinking that
geologic events took place gradually, not all at once.
Bretz's colleagues denounced him, but eventually they realized
that his research was right. By the time Bretz died in 1981, well
into his 90s, he'd been vindicated.
Copyright © 2003, The Associated Press
============
(6) SCIENTISTS HOPE TO GET MORE ACCURATE EARTH AND CLIMATE
HISTORY
The State, 10 November 2003
http://www.thestate.com/mld/thestate/news/nation/7228572.htm
By ROBERT S. BOYD
Knight Ridder Newspapers
WASHINGTON - Scientists have launched a project to construct a
highly accurate calendar of key events in what they call
"deep time," the almost unimaginable span since Earth
was born 4.5 billion years ago.
Sponsors think a precise prehistoric time scale can help them
better interpret what is happening to our planet and predict what
may lie ahead as the world gets warmer. For example, they hope
the project, called CHRONOS (Greek for "time"), will
help settle arguments over the causes and effects of climate
change on the evolution and extinction of species.
Project director Bruce Wardlaw, a geologist at the U.S. Geologic
Survey in Reston, Va., said the purpose was to "produce a
global time scale of Earth's history to solve problems for the
benefit of society."
Researchers are counting on tools and technologies developed over
the last 10 years to greatly increase the accuracy of the
geologic time scale, said Samuel Bowring, a geology professor at
the Massachusetts Institute of Technology in Cambridge.
Bowring told a deep-time conference in Washington in October that
the goal is to achieve a resolution of 1/10th of 1 percent - far
better than the existing errors of 2 percent or more - by 2015.
That would cut some uncertainties from millions to thousands of
years.
Scientists from multiple disciplines are involved in the effort.
Physicists are perfecting their ability to determine the age of a
rock by the rate of decay of radioactive elements. Geologists
recently learned how to relate periodic switches in the magnetism
of the seafloor to events on land. Chemists can precisely date
lava and ashes from ancient volcanoes. Biologists have learned to
read the "molecular clocks" in living cells that tell
when a species was created. Astronomers connect regular changes
in Earth's orbit around the sun to geologic records.
Researchers say a finer time scale is needed because existing
geologic "clocks" are notoriously inaccurate, sometimes
off by millions of years. They are based mostly on evidence
contained in layers of rock laid down eons ago, as can be seen
vividly in the walls of Grand Canyon.
These ribbons of stone are twisted, broken and partly erased by
wind, water, volcanoes and the rise and fall of mountains, making
their interpretation subject to significant errors.
"There are lots of missing sections in the rock
record," Bowring said. Some geologists liken the existing
record to a net - "a lot of holes tied together with
string."
For example, the death of the dinosaurs is commonly blamed on a
giant comet or meteor that smacked into the ocean about 65
million years ago. But geologists can't date the impact to within
a million years, making it uncertain whether the collision
preceded or followed the dinosaurs' extinction.
Project scientists say a special concern is the risk of an abrupt
climate change - a rapid rise or fall of 10 to 20 degrees
Fahrenheit in global temperature in less than a century - as
happened repeatedly in the distant past.
The fear is that the gradual climate warming over the last 150
years could eventually reach a tipping point, as when hot water
suddenly turns to steam, and send the world's temperatures
soaring.
"Climate can change on a dime," said Gerilyn Soreghan,
who teaches geology at the University of Oklahoma in Norman.
"We see more and more evidence for abrupt climate
change," said Isabel Montanez, a geologist at the University
of California in Davis. She said climate records showed that
carbon dioxide - a "greenhouse gas," which contributes
to global warming - was approaching its highest level in 20
million years, long before human ancestors appeared.
"We've seen what happens when CO2 levels go that high; the
climate responds very dramatically," Montanez said. Sea
levels, rainfall, glaciers and plant and animal life all are
affected.
"We know climate varied dramatically in the past, but we
don't really know all the causes," Paul Renne, the director
of the Berkeley Geochronology Laboratory in Berkeley, Calif.,
said in a telephone interview. "If we know how fast things
can happen, then we can gear up for cold snaps or a warm spell
over the lifetime of a few generations."
For example, Renne suggested it might be unwise to keep
rebuilding houses on North Carolina's low-lying Outer Banks,
since global warming already is raising sea levels and increasing
storm damage.
"The study of ancient biology tells us that several times in
Earth's history there have been `near-death' experiences, when
large fractions of the Earth's life suddenly died out from
asteroid impact or changes in atmospheric composition and
climate," Peter Ward, a paleontologist at the University of
Washington, Seattle, wrote in his book, "The Life and Death
of Planet Earth."
"We are likely to, in a way, relive the past," Ward
said.
"The farther back you can look, the farther forward you are
likely to see." - Winston Churchill
On the Web:
For more information on the Web, go to: www.chronos.org and http://eaps.mit.edu/earthtime
========
(7) AND FINALLY: WHILE U.S. AND CHINA ARE BOOMING, EUROPE CUTS
BACK LONG-TERM SPACE PROGRAMME
Space Daily, 8 November 2003
http://www.spacedaily.com/2003/031107184936.ek7zt580.html
The European Space Agency (ESA) announced on Friday that budget
reasons was forcing it to axe
a mission aimed at looking for planets similar to Earth.
The 10-year Eddington planet search mission, due to have been
launched in 2008, has been dropped
and a mission to Mercury by the spacecraft Beppi Colombo has been
reduced, with the scrapping
of a planned lander to that planet, it said.
The decision was made by the ESA executive despite a petition
signed by 414 European astronomers,
who had asked for the Eddington project to be retained.
All rights reserved. © 2003 Agence France-Presse.
-----------
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