PLEASE NOTE:
*
CCNet, 92/2000 - 21 September 2000
----------------------------------
"It's also vital to find such
asteroids as early as
possible. 2000 QW7 and 2000 RD53 didn't
provide much
advance warning. They were discovered 5
and 11
days, respectively, before their closest
approaches to
Earth. 'We can miss bright asteroids
like 2000 QW7 for
several reasons,' explains Eleanor
Helin. 'For
instance, if an asteroid moves across
the Milky Way
during its closest approach, it might be
hard to
identify among the densely-packed
background stars. Or
if the asteroid is close to the Sun as
it approaches,
it could be lost in the Sun's glare.
Many NEAs (like
QW7 and RD53) are in highly elliptical
orbits and
spend most of their time as dim specks
beyond the
orbit of Mars. They brighten only as
they come close
to the Sun, then we can see them from
Earth.'"
-- NASA SCIENCE NEWS,
20 September 2000
"Another puzzle from the satellites
remains. John
Christy of the University of Alabama in
Huntsville
will report that in 1999-2000 the lower
atmosphere
over the tropics is cooler than at any
other time in
the past 22 years. He will cite data
from US weather
satellites that detect
temperature-sensitive microwave
emissions from oxygen in the air, and
independent
confirmation by balloon-borne
thermometers. 'This is
curious,' Christy says. 'According to
the climate
models used to calculate the enhanced
greenhouse
effect, the warming should have been
particularly
rapid in the air over the tropics.'
-- ESA News, 20
September 2000
(1) A GOOD MONTH FOR NEAR-EARTH ASTEROID RESEARCH
NASA Science News for September 20, 2000
(2) UK ADVISED TO STEP UP ASTEROID HUNT
NATURE, 407, 275 (2000)
(3) SPACE DATA IS TAKING THE HEAT OUT OF
GLOBAL WARMING SCARE
European Space Agency, 20 September 2000
(4) WHY BILL NAPIER ISN'T DR STRANGELOVE
Bill Napier <wmn@star.arm.ac.uk>
(5) BOB KOBRES ON THE NEO TASK FORCE REPORT
Bob Kobres <bkobres@uga.edu>
(6) A GOOD CORRECTION FROM THE BAD ASTRONOMER
Phil Plait <badastro@badastronomy.com>
(7) EMERGENCY MANAGEMENT AGENCY FINDS
EXTENSIVE ECONOMIC RISKS OF EARTHQUAKES
ACROSS U.S.
The New York Times, 21 September 2000
(8) AND FINALLY: LIVE FROM THE HOUSE OF COMMONS.....
Ed Grondine <epgrondine@hotmail.com>
==============
(1) A GOOD MONTH FOR NEAR-EARTH ASTEROID RESEARCH
NASA Science News for September 20, 2000
http://spacescience.com/headlines/y2000/ast20sep_1.htm
A Good Month for Asteroids
NASA Science News
Asteroid hunters have enjoyed a close-up look at two new
potentially hazardous space rocks as they passed close to
the Earth in September.
September 20, 2000 -- This has been a good month for
astronomers studying Near-Earth asteroids (NEAs). No fewer
than five sizable space rocks have flown past our planet
since the beginning of September -- three of them in
the last four days.
There was no danger of a collision at any time, say
researchers. All of the asteroids missed our planet by
comfortable margins of 11 to 75 lunar distances. Still, by
cosmic standards, they were close at hand.
Among the parade were two asteroids, 2000 QW7 and 2000
RD53, that were brand-new discoveries. NASA's Near Earth
Asteroid Tracking system spotted 2000 QW7 on August 26,
2000 -- less than a week before its closest approach. Then,
11 days later on Sept. 6th, MIT's LINEAR program detected
2000 RD53. Both were passing by our planet no farther away
than 12 times the distance to the Moon. As news of the
discoveries spread, astronomers rushed to their telescopes
for a closer look.
"Dozens of observers, including many skilled amateurs, are
monitoring these bright objects," says Eleanor Helin, the
principal investigator for JPL's Near-Earth Asteroid
Tracking (NEAT) program. "The close approaches of these
asteroids offer a rare opportunity to learn about their
physical characteristics, including what they're made of
and their rotational periods," she added.
2000 QW7 and 2000 RD53 belong to a group known as
"Potentially Hazardous Asteroids" or PHAs. There are
271
known PHAs, which by definition are asteroids larger than
about 150 meters that can come closer to Earth than 0.05 AU
(about 20 lunar distances). In spite of their menacing
name, none of the PHAs we know of now are destined for a
collision with our planet. But that could change.
"PHA orbits can be chaotic. Perturbations -- such as a
gravitational nudge from Mars or Earth -- could change
their orbits. We have to monitor them -- it's highly
recommended," remarked Helin with a note of understatement.
September 2000 Near-Earth Asteroids
Asteroid
DATE
R Vr
H D
mmm-DD HH:MM (AU) (km/s)
(Vm) (km)
2000
QW7 Sep-01 12:54 0.0317
6.48 19.5 0.3-0.7
2000
ET70 Sep-04 10:39 0.1895
12.84 18.2 0.6-1.4
2000
RD53 Sep-17 13:20 0.0288
7.77 20.0 0.3-0.6
2000 DP107
Sep-19 13:20 0.0478 12.35
17.9 0.7-1.5
2000
QS7 Sep-20 04:54 0.0872
10.28 20.7 0.2-0.5
Legend: R is the asteroid's miss distance in AU
(astronomical units) on the indicated DATE. For comparison,
the distance between the Earth and the Moon is
approximately 0.0026 AU. Vr is the relative velocity
between the Earth and the asteroid at the time of the
flyby. H is the asteroid's absolute magnitude (the visual
magnitude an observer on Earth would record if the asteroid
were placed 1 AU away). D is the size of the asteroid
estimated from its absolute magnitude.
A group of astronomers led by Jean-Luc Margot of the
National Astronomy and Ionosphere Center detected radar
echoes from 2000 QW7 and 2000 RD53 as they passed over the
powerful Arecibo radar in Puerto Rico and NASA's Goldstone
radar in the Mojave desert. By analyzing the echoes,
researchers can construct three-dimensional maps of the
asteroids and reduce the uncertainty of their orbital
elements.
"Goldstone radar observations of 2000 QW7 and RD53
permitted velocity measurements accurate to better than 4
millimeters per second," says Jon Giorgini, a senior
engineer in JPL's Solar System Dynamics Group "For 2000
RD53, it was possible to make direct range measurements to
the asteroid, from both Arecibo and Goldstone planetary
radars, accurate to at least 300-400 feet."
With a precise orbit determined by radar data, Giorgini ran
2000 RD53's motion backwards and found that it had made an
even closer approach at 9.3 lunar distances in 1933, but no
one saw it. The next close encounter as near as this week's
won't come until 2198.
According to Giorgini's calculations, 2000 QW7 will be back
sooner than 2000 RD53. On Sept. 15, 2019, it will pass our
planet 14 times farther away than the Moon -- about the
same distance as this week's encounter.
"Evidence from the radar data suggests that 2000 QW7 is a
slow rotator," added Jean-Luc Margot. "Its spin period
is
on the order of days, which is a puzzle for an object this
size."
Collisions within the asteroid belt are expected to give
space rocks plenty of spin, but 2000 QW7 joins at least two
other NEAs (1999 JM8 and Toutatis) that rotate slowly.
"Various exotic possibilities have been proposed to explain
how NEAs could lose their angular momentum," continued
Margot. "These include close encounters with a planet,
tidal despinning of a binary system, or disruption from a
larger asteroid. Obtaining these radar measurements will
help us understand ... their dynamical history."
Slow rotation is just one of many puzzles attending
Potentially Hazardous Asteroids, says Brian Marsden,
director of the Minor Planet Center. Researchers still
don't know how many PHAs inhabit the inner solar system,
what they're made of, or exactly where they come from.
"There are two obvious possibilities," says Marsden.
"PHAs
could come from the asteroid belt or they might be inert
comets. Undoubtedly it's a mixture of the two, but we don't
know the fractions."
"We would expect some to be bona fide rocky asteroids,"
he
continued. "After all, there are mechanisms that can bring
main belt asteroids into Earth-crossing orbits. The
principal one, involving what are called secular planetary
perturbations, takes millions to hundreds of millions of
years -- a short time compared to the age of the Solar
System."
"As for the comets, it may be that they can masquerade as
asteroids after their ices have been vaporized by solar
heating. Is there enough particulate material for such a
spent comet to remain coherent, or does it break up? Comet
LINEAR broke up very nicely (when it passed by the Sun
earlier this year)! An alternative is that a rocky crust
might completely cover the comet's ice. We just don't
know."
Distinguishing between cometary and rocky NEAs is important
in case we ever need to nudge one away from our planet. One
of the most-often discussed scenarios for diverting a PHA
involves launching a nuclear-armed rocket to intercept it.
Exploding the warhead in the wrong spot could have
unintended consequences. Scientists caution that a
hailstorm of asteroidal fragments could be worse than one
big piece -- like being hit by a shotgun instead of a
rifle. Knowing what PHAs are made of and how they are put
together is vital.
It's also vital to find such asteroids as early as
possible. 2000 QW7 and 2000 RD53 didn't provide much
advance warning. They were discovered 5 and 11
days, respectively, before their closest approaches to
Earth.
"We can miss bright asteroids like 2000 QW7 for several
reasons," explains Helin. "For instance, if an asteroid
moves across the Milky Way during its closest approach, it
might be hard to identify among the densely-packed
background stars. Or if the asteroid is close to the Sun as
it approaches, it could be lost in the Sun's glare. Many
NEAs (like QW7 and RD53) are in highly elliptical orbits
and spend most of their time as dim specks beyond
the orbit of Mars. They brighten only as they come close to
the Sun, then we can see them from Earth."
"The way to look at these objects is over a long period of
time," noted Marsden. "Yes, some will come close to
Earth
and miss us -- as 2000 QW7 and RD53 have done -- but it's
the subsequent passes that we have to worry about.
Follow-up observations to establish precise orbits are very
important if we wish to predict future encounters."
"Radar helps a very great deal (in refining asteroid
orbits). We can also look for newly discovered asteroids in
old images, and that helps, too. Nowadays we look for
pre-discovery images as a matter of course."
Indeed, soon after NEAT identified 2000 QW7, a colleague of
Marsden's found this asteroid in early-August data from
MIT's LINEAR search program. Such prediscovery
observations, and in particular confirmed "precovery"
observations from an earlier year, can immediately refine
an asteroid's orbit and make continued tracking easier.
"LINEAR did record 2000 QW7 almost a month before its
closest approach," says Marsden, "but poor weather
limited
the observations to a few images on a single night, and it
was moving too slowly to be picked out as unusual." It's
another example of how search programs can miss PHAs. When
they are faint, far away, and moving slowly against the
background stars, PHAs can appear to be harmless main belt
objects.
"We're accumulating asteroids at a furious rate," says
Marsden. "At the turn of the century we knew of only 500
minor planets; now we've cataloged 17,349 with excellent
orbit determinations. The rate of discovery is approximately
doubling every two years."
The rate could increase further if a new British government
initiative to identify hazardous asteroids bears fruit.
With more telescopes on the lookout, astronomers will
undoubtedly enjoy many more -- and perhaps uncomfortably
numerous -- opportunities for close-up studies of these
ever-scary space rocks.
The Anatomy of Asteroid Names
Sometimes it seems that astronomers enjoy picking
inscrutable names for the objects they study. What person
on the street would guess that "2000 QW7" is a
fascinating
space rock? Nevertheless, there is a method to this naming
madness.
So many new asteroids are discovered each month that
astronomers need an efficient way to catalog them. The
first part of "2000 QW7" is simple -- it identifies the
year of the asteroid's discovery (2000).
Then comes "QW7." The first letter tells us that the
object
was identified during the second half of August. Each
half-month is identified with a letter of the alphabet.
January 1st-15th = "A"; January 16th-31st =
"B"; August
16th-31st = "Q", etc. The letter "I" is
omitted in this
system.
The second and third characters "W7" are a shorthand
way of
counting the number of asteroids found during the 2nd half
of August 2000. The first asteroid discovered was "2000
QA"; the second was "2000 QB;" The second letter
cycles
through the alphabet until it reaches "Z" and then it
goes
back to the beginning with an extra number. So, the 26th
asteroid discovered during the second half of August 2000
was "2000 QA1". Remember that "I" is omitted,
so "A1"
corresponds to the 26th asteroid, not the 27th. This means
that 2000 QW7 was the 197th asteroid found in the second
half of August 2000!
NEAT is managed by JPL for NASA's Office of Space Science,
Washington, DC. The National Astronomy and Ionosphere
Center is operated by Cornell University under a
cooperative agreement with the National Science Foundation
and with additional support from NASA.
Web Links
Near Earth Objects - learn more about nearby space rocks:
http://neo.jpl.nasa.gov
==============
(2) UK ADVISED TO STEP UP ASTEROID HUNT
From NATURE, 407, 275 (2000)
By Natasha Loder
[LONDON] The British government may take a bigger part in
international efforts to identify objects in space that
threaten the Earth. Such a move has been urged by an
independent panel known as the Near Earth Objects Taskforce
set up by the science minister, Lord Sainsbury, whose
report was published in London this week.
Other recommendations include building a three-metre
telescope in the Southern Hemisphere, and dedicating the
one-metre Johannes Kapteyn Telescope on La Palma in
the Canary Islands to following up observations of
near-Earth objects (NEOs).
Sainsbury said that although the possibility of a dangerous
NEO hitting the Earth was "extremely remote", it had
potentially serious consequences. "We put a lot of money
into astronomy, and I think it is sensible to put a bit
into making certain that we know if there is any danger of
an object hitting our very fragile planet."
He added that he plans to consult with ministerial
colleagues and international bodies about how the
government should respond to the committee's proposals.
The taskforce argues that international missions could
detect NEOs while making other observations. It says the
government should ask the European Space Agency to ensure
that one of its future missions also surveys the sky for
such objects.
The taskforce also says that the Minor Planet Center at the
Smithsonian Astrophysical Observatory in Cambridge,
Massachusetts, should be put on a "robust international
footing".
© 2000, Macmillan Publishers Ltd.
====================
(3) SPACE DATA IS TAKING THE HEAT OUT OF
GLOBAL WARMING SCARE
From the European Space Agency, 20 September 2000
http://sci.esa.int/content/news/index.cfm?aid=1&cid=1&oid=24610
CLIMATE CHANGE: NEW IMPRESSIONS FROM SPACE
20-Sep-2000 Are variations in the Sun´s brightness an
important cause of climate change? Could changes in the
Sun´s magnetism affect the Earth´s clouds? Why do
temperature trends in the lower atmosphere give a different
impression of global warming from measurements at ground
level? The latest results from spacecraft that observe the
Sun and the Earth provoke many such questions. They will be
debated next week on the Spanish island of Tenerife, where
scientists who calculate climate change due to manmade
greenhouse gases will meet others who argue that solar
effects have been underestimated.
The European Union and the European Space Agency are
sponsoring the conference entitled "The Solar Cycle and
Terrestrial Climate", 24-29 September. It is hosted in
Santa Cruz de Tenerife by the Instituto de Astrofísica de
Canarias. More than 40 speakers from 15 countries
will review the Sun´s erratic behaviour and its possible
climatic effects, in the most comprehensive meeting on this
subject for many years.
"To those of us who observe it every day, the Sun is a wild
beast, and no one doubts that its variations affect the
climate to some degree," says Brigitte Schmieder of the
Observatoire Paris-Meudon, France, co-chairman of the
scientific committee that planned the meeting. "The
arguments in Tenerife will be about the mechanisms of the
solar influence, and its importance compared with the human
factor."
Claus Fröhlich of the Physikalisch-Meteorologisches
Observatorium, Switzerland, will report the latest results
from his VIRGO instrument on the ESA-NASA SOHO spacecraft.
These show an increase of about 0.1 per cent in visible
solar radiation since SOHO was launched in 1995, at the
last sunspot minimum. But this is a cyclical variation and
comparisons with results from earlier spacecraft show no
overall increase since the 1980s.
The relatively small variations in the Sun´s brightness
observed by satellites encouraged the Intergovernmental
Panel on Climate Change to propose in 1990 that global
warming in the 20th Century was due mainly to carbon
dioxide and other heat-trapping greenhouse gases added to
the air by human activity. It predicted severe global
warming in the 21st Century as a result of this enhanced
greenhouse effect.
These opinions were reconfirmed in a later report, Climate
Change 1995. A third major assessment is now in
preparation. Sir John Houghton of the Intergovernmental
Panel´s science working group will report at the Tenerife
meeting on the issues being addressed. One is a
reconsideration of the historical role of other natural
agents of climate change, including the Sun.
There were no satellites in 1700, when the Sun was
unusually inactive and Europe was very chilly, but many
experts suppose that solar radiation has intensified since
then. Two conference speakers, Marcel Fligge of the ETHZ
Institut für Astronomie, Switzerland, and Sami Solanki of
the Max-Planck-Institut für Aeronomie, Germany, have just
published estimates that the average visible light
increased by 0.2 % during the past 300 years, and
ultraviolet rays by 0.7 %.
"It requires precise space observations to detect the
subtle solar brightening at the peak of the sunspot cycle,"
Solanki notes. "To evaluate long-term climatic effects, we
have to make the most of just two decades of space
measurements and use models to reconstruct the larger
changes in the past."
A discovery made with help from the ESA-NASA Ulysses
spacecraft is that the Sun´s magnetic field in the Earth´s
vicinity doubled in strength during the 20th Century. Mike
Lockwood of the Rutherford Appleton Laboratory, UK, will
discuss this symptom of a more active Sun. It can be used
to estimate increases in brightness, which were apparently
greater in the first half of the century than in the
second half.
The intensifying magnetic field, carried by the solar wind,
also reduced the number of cosmic rays reaching the Earth
from the Galaxy. According to another speaker, Henrik
Svensmark of the Danish Space Research Institute, the
shortage of cosmic rays reduced the Earth's cloudiness, so
enabling the world to warm up. In 1996, Svensmark found
that cloudiness gauged from weather satellites such as
Meteosat apparently varied according to the intensity of
cosmic rays.
Using improved data from the International Satellite Cloud
Climatology Project, Svensmark and his colleague Nigel
Marsh now link cosmic-ray variations chiefly with low
clouds over the tropical oceans. Meteorologists have been
sceptical about any effect of cosmic rays on cloud
formation, but in April this year atmospheric chemists at
the University of California, Los Angeles, suggested a
mechanism. In clean oceanic air, cosmic rays may facilitate
the formation at low altitudes of sulphuric acid particles,
on which cloud droplets form.
A proposed experiment at CERN, the European particle
physics laboratory in Geneva, is intended to test
mechanisms like that. Jasper Kirkby from CERN will explain
how pulses of particles can simulate cosmic rays, in a
purpose-built cloud chamber matching conditions in the
atmosphere. Besides the atmospheric and particle
physicists, space scientists from the Danish Space Research
Institute and the UK´s Rutherford Appleton Laboratory have
joined the team for this experiment, called CLOUD.
Meanwhile, various combinations of natural influences and
manmade emissions have been compared with the sequence of
temperature changes of the 20th Century, in a computer
model at the Hadley Centre for Climate Prediction and
Research, UK. Simon Tett will describe the results at the
Tenerife meeting. The warming in the early part of the
century is best explained by changes in solar brightness, a
scarcity of explosive volcanoes, and internal climate
variability. On the other hand, the model indicates that
the human influence was the chief cause of recent warming.
"The effect of greenhouse gases was masked by the cooling
effect of anthropogenic sulphate aerosols until the 1960s,"
Tett comments. "This allowed the Sun and other natural
forcings to play their part in climate change. Now we see
the gases beginning to overcome the cooling effects of
volcanoes and anthropogenic sulphate aerosols. Since the
1963 eruption of Agung the cooling from volcanic aerosols
has offset the small warming from increases in solar
irradiance and this cooling has been overwhelmed by warming
from greenhouse gases."
Another puzzle from the satellites remains. John Christy of
the University of Alabama in Huntsville will report that in
1999-2000 the lower atmosphere over the tropics is cooler
than at any other time in the past 22 years. He will cite
data from US weather satellites that detect
temperature-sensitive microwave emissions from oxygen in
the air, and independent confirmation by balloon-borne
thermometers. "This is curious," Christy says.
"According
to the climate models used to calculate the enhanced
greenhouse effect, the warming should have been
particularly rapid in the air over the tropics."
Europe will join in the watch on atmospheric temperatures
from space, when the first Metop satellite, being developed
by ESA for Eumetsat, goes into a polar orbit in 2002. Its
instruments will include an advanced microwave sounding
unit provided by the USA.
The climate conference in Santa Cruz de Tenerife is
accompanied by other meetings about the Sun. Sessions
organized on 29 September by the Joint Organization for
Solar Observations will review data handling, instruments,
and the August 1999 solar eclipse. On 30 September, the
European Solar Magnetometry Network will convene. In the
following week, 2-6 October 2000, helioseismologists of
SOHO and the ground-based GONG project will gather for a
workshop on "Helio- and Asteroseismology at the Dawn of the
Millennium".
Paal Brekke of ESA will give a popular talk on "The
Sun
through the eyes of SOHO" on 29 September at 20:00 in the
Cajacanarias Conference Center. ESA will publish the
proceedings of "The Solar Cycle and Terrestrial
Climate"
conference in a few months´ time.
=============================
* LETTERS TO THE MODERATOR *
=============================
(4) WHY BILL NAPIER ISN'T DR STRANGELOVE
From Bill Napier <wmn@star.arm.ac.uk>
Dear Benny,
Just a footnote to Alasdair Beal's note about the use of
nukes to divert asteroids. Alasdair has picked up on an
inaccurate quote, and I don't want the impression to be
given that I'm advocating nukes or, for that matter, not
advocating them. So far the only comment I've made on the
issue is that the use of nukes may be the only possible way
to effect a last-minute deflection. For another conceivable
misuse of PHAs, read my novel NEMESIS (My second novel,
REVELATION, came out in June. Of course some colleagues
regard all my work as fiction :-)
Bill Napier
===============
(5) BOB KOBRES ON THE NEO TASK FORCE REPORT
From Bob Kobres <bkobres@uga.edu>
A few comments on the NEO report from the British government:
I'm glad that the comet inclusive term NEO was adopted. It
would be more in keeping with this broader acronym to also
adopt the term PHO rather than referring to potentially
hazardous asteroids as defined in the glossary.
http://abob.libs.uga.edu/bobk/ccc/cc042897.html
The more difficult to predict risks from comets are
generally well addressed. The concerns expressed by Hoyle
and Wickramasinghe with regard to near misses (CCNet
09/18/00) should not be overlooked.
http://abob.libs.uga.edu/bobk/ccc/ce062299.html#lexbobk
http://abob.libs.uga.edu/bobk/ccc/cc060898.html#lexmars
http://abob.libs.uga.edu/bobk/ccc/cc091800.html
The opportunity to find rational and public support for
accelerated Space infrastructure development is not well
developed in the report. Stick/carrot--PHOs to BROs:
http://abob.libs.uga.edu/bobk/ccc/cc031898.html#wack
http://abob.libs.uga.edu/bobk/ccc/cc031700.html#focus
http://abob.libs.uga.edu/bobk/nica.html
The report is candid in recognizing that nuclear devices
are going to be required to ensure that we have as much
potential as possible to prevent future impact events.
http://abob.libs.uga.edu/bobk/ccc/cc062598.html#NUKES
I was particularly glad to see that the report mentioned
funding studies of how impacts may have influenced the near
past. At least I hope this needed research is covered by
recommendation 8! Digging in to learn the actual number of
recent significant impact events is the only way to
confidently reckon our contemporary level of risk.
http://abob.libs.uga.edu/bobk/ccc/cc060398.html
[Omitted here was a comment on erratic naming conventions
with excerpts from (1) above, which uses NEA and PHA
though making a point of the difficulty in determining the rocky
or cometary composition of these OBJECTS. Hence my bad pun:]
PHO-get-it. . .at least we seem to making progress!
8^)
Later.
bobk
===============
(6) A GOOD CORRECTION FROM THE BAD ASTRONOMER
From Phil Plait <badastro@badastronomy.com>
Benny--
In the most recent CCNet (20 September 2000) Joan and David
Dunham
report:
>>From The BBC News Online, 16 September 2000
>>http://news.bbc.co.uk/hi/english/sci/tech/newsid_927000/927991.stm
>>No one has ever been killed, or even injured by an
asteroid . .
>That's not true - a woman in (USA) Georgia was badly
>bruised by a large meteorite that crashed into her home in
>1953. But maybe it was too small to be classified an
>"asteroid"? More recently in Uganda, a village was
pelted
>with stones from the breakup of a large meteor, and a boy
>was hit on the head by a small rock, but the account didn't
>mention him being injured by it.
The woman injured by the meteorite was a Mrs. Annie Hodges
of Sylacauga, Alabama. It was on November 28, 1954. The 4
kilogram meteorite left a huge bruise on her upper
leg/side; I have vivid memories of seeing a picture of it
in the Time/Life science series book "Earth". The
meteorite
pierced her roof, smashed a radio and ricocheted off,
hitting her. This story breaks two separate myths of
meteorite falls: one is that they all come it at hypersonic
speeds and are burning hot when they hit. In reality, small
ones are slowed by atmospheric friction so that they are
falling at terminal velocity at the time of impact.
Friction does initially heat them, but the outer parts
ablate away, leaving the relatively cool interior exposed
on impact. Once they reach terminal velocity, they cool as
they fall.
There may have been other injuries or even deaths
attributed to meteorites. Planetologist John Lewis has a
long list of possible meteorite related injuries and
property damage in his book "Rain of Iron and Ice"
(Addison-Wesley Publishing, 1996, ISBN 0-201-48950-3). It's
a fascinating list, and punctuated by many pages of
anecdotes from history. Mrs. Hodges is listed there as
well.
-Phil Plait
The Bad Astronomer
Phil
Plait
badastro@badastronomy.com
The Bad Astronomy Web Page: http://www.badastronomy.com
===============
(7) EMERGENCY MANAGEMENT AGENCY FINDS EXTENSIVE ECONOMIC
RISKS OF EARTHQUAKES ACROSS U.S.
From The New York Times, 21 September 2000
http://www.nytimes.com/2000/09/21/science/21QUAK.html
By KENNETH CHANG
While California suffers the most economic harm from
earthquakes, cities in other parts of the country, like
Seattle, New York, Salt Lake City and St. Louis, are
also at risk of heavy damage and should be doing more to
prevent such harm, the Federal Emergency Management Agency
said yesterday.
The agency conducted the study, its first nationwide
projection of earthquake losses in monetary terms, to guide
disaster planners and to show that earthquakes can be as
economically devastating as hurricanes and flooding.
FULL STORY at
http://www.nytimes.com/2000/09/21/science/21QUAK.html
========
(8) AND FINALLY: LIVE FROM THE HOUSE OF COMMONS.....
By Ed Grondine <epgrondine@hotmail.com>
QUESTIONS AND ANSWERS, or THE YOUTH OF TODAY ARE THE
LEADERS OF TOMORROW
Featuring handsome and charming TONY BLAIR as PM, with
RICK, NEAL, VIVIAN, MIKE, and ALEX as the right honorable
MPs for the ridings of Eastcentral, Abergewilly, Dunditit,
Carngate, and Sludgepool respectively.
TONY: I'm very proud to present to you here today the
Report of Our Task Force on Potentially Dangerous Objects.
I'm sure you'll agree with me that they deserve our thanks
for a difficult job well done...
VIVIAN: (sotto voce aside) oh christ, more wonks...
TONY: Their report clearly indicates that something needs
to be done to deal with this hazard, and my Government is
taking under careful consideration their recommendation to
build a big telescope to find these things.
MIKE: (sotto voce aside) they're goes the club fees...
(rises to stand)
Mister Prime Minister, how can you justify asking more from
the taxpayers of this country when a quick glance through
the report shows that only one of these things "may
have"
possibly hit China a couple of hundred years ago?
TONY: Because of the high numbers of people killed when
they do hit.
MIKE: But according to this, they seem to hit Siberia and the
Brazilian jungle, and the only one that may have killed
anyone might not have happened at all, and if it did, it
killed only 10,000 Chinese. Certainly China has enough
people so that they won't be missed.
TONY: I'm afraid my right honorable friend has missed the
point. The next one could hit Britain.
MIKE: But in the last thousand years the only one that "may
have" hit and killed anyone hit in China.
TONY: There were other reports of other recent impacts
elsewhere that killed large numbers of people, but they
were ignored at the insistence of some of our American
friends.
MIKE: Well if they want to ignore them, maybe we should
too...
TONY: Just because we politely defer to our American
colleagues' insistence, doesn't mean that they didn't
happen.
MIKE: Well then, could we cancel something else? Say this
other telescope, VISTA?
TONY: VISTA has clear scientific objectives within the
framework of European science, and we can not abandon our
commitments.
MIKE: argh...(sits) (NEIL rises...)
NEIL: Uhhh.. I think he's right, you know. I was reading
this book the other night, and it said that Atlantis and Mu
were both destroyed when comets hit them.
(close shot of TONY looking hopelessly skyward.)
RICK (rises quickly): I just want to point out to my
colleague that simply EVERYONE knows Atlantis and Mu are
entirely fictional, but when "I" was researching on the
internet the other night "I" saw that large parts of
South
America were pretty much set on fire by one of these
things.
MIKE: No it wasn't, it's not in the report. Where does it
say in the report that parts of South America were set on
fire?
TONY: My colleague from Eastcentral is most certainly
correct in this matter.
VIVIAN: The destruction of large parts of South America is
ommited from the report? Why?
TONY: Let's just say that some opinions carry more weight
than others ...
RICK: The piece that "I" read said that the impact had
left
these big holey crater things in Argentina...
TONY: Once again my colleague from Eastriding is correct,
and allow me to mention that I'm very much looking forward
to his report on the degradation of young women that is
being promoted via the internet.
VIVIAN: (sotto voce) still at it... (rises)
Why don't we just blow them up then?
TONY: "Blowing them up" may lead instead to the
creation of
even more dangerous fragments.
VIVIAN: Then use a bigger bomb.
TONY: The report recommends that the possibility of using a
nuclear charge to deflect one of these be looked into.
NEIL (still standing): Uhhh... I don't know about that...
It'd be all fissiony and all that...
TONY: Naturally the nuclear charges would have to be under
the control of the United Nations and there would be
adequate safeguards.
MIKE: You want to use OUR money to give the UN A-bombs?
TONY: Well, they wouldn't be the UNs really, they'd still
be ours, but the UN would safeguard them.
VIVIAN: Well then, why don't we just skip all this, and
blow them up then?
TONY (Close shot as the light comes on): We have to find
them first.
VIVIAN: okay - let's find them and blow them up.
ALEX (rises): The report makes no mention of using the
resources of the great people of the former Soviet Union to
deal with this hazard.
TONY: They're broke.
ALEX: Well, then, why don't we help those people in their
time of need and buy those resources from them to deal with
this problem?
TONY: I understand that our American friends have schemes
underway to make some use of those resources, but further
will have to depend on their announcement of their plans.
MIKE: Will we have to pay anything?
TONY: No.
MIKE: Sounds good to me. Let's let the Americans do it...
ALL MEMBERS (loudly): Aye...
TONY: Moving on to other business, I'd like to tell you
today about our plans for dealing with the fuel crisis...
----------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
----------------------------------------
The CCNet is a scholarly electronic network. To
subscribe/unsubscribe,
please contact the moderator Benny J Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
educational use only. The attached information may not be copied
or
reproduced for any other purposes without prior permission of the
copyright holders. The fully indexed archive of the CCNet, from
February 1997 on, can be found at http://abob.libs.uga.edu/bobk/cccmenu.html