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(meteorobs) Excerpts from "CCNet 108/2001 - 17 October 2001"
A wonderful public press item on the Leonids at bottom this issue...
from Discovery magazine and the folks at Disney, no less! :)
Clear skies,
Lew Gramer
------- Forwarded Message
From: Benny Peiser <B.J.Peiser@livjm.acdot uk>
To: cambridge-conference <cambridge-conference@livjm.acdot uk>
Subject: CCNet 108/2001 - 17 October 2001
Date: Wed, 17 Oct 2001 10:50:38 +0100
CCNet 108/2001 - 17 October 2001
================================
[...]
(6) A 600-KILOMETER SPACE POTATO
Andrew Yee <ayee@nova.astro.utorontodot ca>
(7) FIREBALL SEEN IN CANADIAN SKY
Ron Baalke <baalke@jpl.nasadot gov>
(8) BLAST FROM THE PAST
Discovery, November 2001
[...]
======================================================================
(6) A 600-KILOMETER SPACE POTATO
>From Andrew Yee <ayee@nova.astro.utorontodot ca>
[Extracted from inScight, Academic Press
http://www.academicpress.com/inscight/10152001/graphb.htm]
Monday, 15 October 2001, 5 pm PST
A 600-Kilometer Space Potato
By ROBERT IRION
Astronomers have detected a surprisingly irregular object in the dark
reaches of the outer solar system. Orbiting within the Kuiper Belt, a vast
cloud of icy debris left over from the solar system's formation, the oddball
is estimated to be 600 kilometers long but just 360
kilometers wide, making it one of the largest elongated bodies ever
detected. With further study, this primitive object and its cousins could
help clarify how the outer solar system formed.
Astronomers found the first Kuiper Belt object (KBO), circling beyond
Neptune, in 1992. To date, telescopes have revealed more than 400 KBOs in
our outer solar system with diameters of at least 100 kilometers; 70,000
such bodies may exist. Because they are as dark as charcoal and too distant
to resolve photographically, KBOs are difficult to study. Astronomers must
deduce their properties from the meager pinpoints of light they reflect.
In 1999 and 2000, astronomers detected an unusual pattern of light from a
KBO called 1998 SM165. Its brightness varied by 50% every 4 hours,
indicating something odd, because brightness normally remains steady. A team
led by astronomer William Romanishin of the University of Oklahoma, Norman,
considered whether surface markings, such as a bright hemisphere and a dark
one, could explain the data. But that calculation seemed implausible, so the
researchers derived a better
explanation: a potatolike shape, reported in the 9 October issue of the
Proceedings of the National Academy of Sciences. In this case, the object
rotates once every 8 hours, pointing a narrow end and then its broader side
toward Earth.
The optical properties of dirty ice suggest that the object is probably 600
kilometers by 360 kilometers. "One would think that gravity would make
something this size into a spherical object," says team member Stephen
Tegler of Northern Arizona University in Flagstaff. He speculates that 1998
SM165 may be the shattered remnant of a collision or the merger of two
smaller, more spherical objects. Such an origin would shed light on the
dynamics of the Kuiper Belt, which periodically sends comets toward the sun.
An elongated shape makes sense, says astronomer Robert Millis, director of
Lowell Observatory in Flagstaff. However, he notes that little is known
about KBOs, and other explanations, such as bizarre surface patterns, remain
possible. NASA's Space Infrared Telescope Facility, scheduled for launch in
July 2002, might offer more answers when it scans the heat emitted by KBOs.
) 2001 The American Association for the Advancement of Science
====================================================================
(7) FIREBALL SEEN IN CANADIAN SKY
>From Ron Baalke <baalke@jpl.nasadot gov>
http://wwwdot canoedot ca/CalgaryNews/cs.cs-10-15-0015.html
Fireball seen in sky
By MICHELLE MARK
Calgary Sun (Canada)
October 15, 2001
A booming fireball streaked through the sky yesterday leaving bewildered
Calgary-area residents rubbing their eyes in disbelief.
While it is still unclear where pieces of the object eventually landed, some
reports indicated they may have fallen in the Northwest Territories.
Full story here:
http://wwwdot canoedot ca/CalgaryNews/cs.cs-10-15-0015.html
============================================================
(8) BLAST FROM THE PAST
>From Discovery, November 2001
http://www.discover.com/nov_01/featsky.html
Blast From the Past
Heads up: Here comes space junk from 5 billion years ago
By Bob Berman
Can a stone no larger than an apple seed make people gasp in amazement?
Sure, when it punches through the air 70 times faster than a bullet. At such
a speed, intense friction heats both the rock and the surrounding air
molecules to incandescence, producing a brilliant streak. Play that again
every second, and you've got a meteor storm.
In an era of mind-twisting cosmological puzzles, few astronomers have wanted
to hitch their careers to the study of space debris. Yet meteors keep
observatory phones ringing. This month may up the ante with one of the
finest displays in decades. The annual Leonid meteor shower should escalate
into a long-awaited, torrential meteor storm in the predawn hours of
November 18, when those who aren't under cloud cover may see 4,000 meteors
per hour. Soon after, the Geminids--the richest of the year's consistent
showers--will blast Earth on December 13 and 14.
And now these blazing bits are starting to get some respect. Astronomers
have come to recognize that meteors--flecks of rock shed from the
evaporating ices of comets or, in rarer cases, from colliding asteroids--are
unique time capsules from the formation of the solar system. Whereas
planetary rocks have been corrupted by wind, rain, and geological
reprocessing, meteoroids often remain much as they were 4.6 billion years
ago, when Earth began to form. NASA has even dispatched a spacecraft, called
Stardust, to collect meteorlike material from comet Wild 2 in 2004.
Part of the thrill of a meteor shower is that it requires no star knowledge.
Still, science sneaks in: Even casual viewers can tell November's Leonids
are very different from December's Geminids. The Leonids strike our planet
head-on, producing bright, lightning-fast streaks that often leave glowing
trails. These scattered remnants of the comet Tempel-Tuttle usually produce
only a weak shower. Every 33 years or so, however, the meteors abruptly
arrive thick and furious, indicating Earth has passed through the densest
parts of the comet's dusty trail. This happened in 1833 and in 1966, when an
hour-long torrent of 40 meteors per second captivated and terrified
onlookers in the American West.
The Geminids, being much more uniformly distributed, put on a comparatively
modest but reliable show, spewing out one-a-minute meteors like a tireless
vending machine. Visible from everywhere and continuing all night long,
these fragments of the asteroid Phaethon will hit Earth sideways and cross
the sky at just 22 miles per second, half the speed of a typical Leonid.
Only 3 percent leave trails.
Meteor experts anticipate great things from the Leonids this year. Each time
Tempel-Tuttle passes close to the sun, the comet disintegrates a bit and
leaves behind a new stream of dust. Earth should plow right through three
streams this year. The eastern United States has been favored to witness the
first swarm, which could deliver a meteor every few seconds from 4 to 6 a.m.
EST on November 18. Eight hours later, researchers forecast, a much denser
swarm may light up eastern Asia with as many as seven meteors per second.
But in a late-breaking development, meteor guru Peter Jenniskens of NASA's
Ames Research Center now concludes the richest storm will occur over the
United States and Canada.
The Leonid's streams are so compact that each storm lasts only about as long
as a movie. That is why only those waiting at the lucky longitudes will see
the incoming bullets. That is also why predicting the storm is such dicey
business. Obviously, anyone with clear skies should check the heavens that
night, especially before dawn. You might see the astronomical sight of a
lifetime.
) Copyright 2001 The Walt Disney Company.
==========
(9) BIRTH OF URANUS' PROVACATIVE MOON STILL PUZZLES SCIENTISTS
>From Space.com, 16 October 2001
http://www.space.com/scienceastronomy/solarsystem/miranda_creation_011016-1.
html
By Andrew Chaikin
Editor, Space & Science
Some of the most bizarre sights in the solar system have been seen - by
robotic eyes - on the moons of the giant outer planets. Eruptions of liquid
sulfur on Jupiter's moon, Io. A global shell of ice, laced with cracks and
ridges, on nearby Europa. Ice volcanoes on Neptune's satellite, Triton. And
an opaque layer of orange smog hiding Saturn's moon, Titan. But nothing
stranger than the tortured, jumbled surface of a tiny satellite of Uranus
called Miranda.
In the minds of many planetary scientists, Miranda is the solar system's
strangest moon. But the main theory about how it formed, after being blown
to bits, is being questioned by recent thinking.
Miranda's discovery in 1948 by astronomer Gerard Kuiper was an
accomplishment: Only 290 miles across and almost 2 billion miles from Earth,
the tiny moon appears as a mere speck of light in the largest telescopes.
Almost nothing was known about it until the Voyager 2 spacecraft made its
historic reconnaissance of Uranus and its satellites in January 1986. As
Voyager swept past the seventh planet, it passed close to Miranda, and sent
back a series of stunning, high-resolution images, some of which showed
features less than half a mile across.
Anyone who witnessed those photographs as they appeared on monitors at the
NASA/Caltech Jet Propulsion Laboratory on Jan. 25 will never forget the
moment.
The first closeup, of Miranda's curved horizon, showed a sawtooth pattern of
ridges, along with an unintelligible collection of light and dark
rectangles. Then came a large, bright streak shaped like a chevron, set
within a patch of dark, tortured ground; it had caught scientists' attention
in earlier, less detailed pictures but now was revealed in all its
strangeness. This in turn was surrounded by a battered expanse of craters
resembling the lunar highlands.
Along the edge of Miranda's sunlit face, a wide band of ridges and grooves
cut across the surface like a racetrack and made a right-angle turn before
disappearing into the darkness. Finally, there was a range of forbidding
mountains, sliced by a towering cliff several miles high.
Planetary scientists could only stare in disbelief. Some had predicted that
Miranda would be far too small to show any signs of geologic activity. And
yet, its surface had turned out to be a collection of the strangest
landforms the solar system had to offer. Geologist Larry Soderblom of the
U.S. Geological Survey called Miranda "a bizarre hybrid of the valleys and
layered deposits on Mars, combined with the grooved terrain on Ganymede, and
the compressional faults of Mercury."
At first, it seemed impossible to make any sense out of the bewildering
variety of terrains. What created the jumbles of light and dark, such as the
"chevron" pattern? What were the bizarre "racetrack" patterns? Nothing like
Miranda's surface had ever been seen before, and explaining it all was a
tall order.
However, as scientists debated the findings, an explanation emerged:
Billions of years ago, Miranda had been the victim of a cosmic collision, an
impact so violent that it had broken the moon into pieces - some icy, some
rocky. Later on, said the theory, these fell back together into a
hodge-podge of chunks. Relatively pure ice would show up as bright areas,
while dark areas would consist of ice mixed with carbon-rich compounds
darkened by exposure to high-energy cosmic radiation.
The idea of a moon being blown apart and reassembled wasn't new.
In fact, scientists had already debated the possibility after Voyager
photographed Saturn's moon Mimas in 1980. One face of Mimas was scarred by a
crater so big that the impact must have come close to shattering the tiny
moon. In all likelihood, Mimas had sustained even larger impacts during the
solar system's early history. It might have been broken up and reassembled
not just once, but several times.
After seeing Voyager 2's images, some scientists believed the same thing
could have happened to Miranda.
And the re-assembly process, they proposed, explained Miranda's present
appearance: Once the moon's fragments coalesced, rocky chunks, being denser
than ice, would have tended to sink toward the center. The resulting
friction, said the theory, would have warmed the moon's icy interior and
created circulating currents of icy material within the interior, like a
frigid, slow-motion version of a pot of boiling soup.
Above these slowly churning currents, the crust would have been compressed
in some places, producing the "racetracks" of ridges and grooves. In other
places within the dark areas, fresh, light colored ice would have erupted to
the surface, producing the "chevron."
With the mystery apparently solved, Miranda slowly faded from most
scientists' view. But is the "broken moon" theory really the answer? Not to
planetary geologist Bob Pappalardo of the University of Colorado at Boulder.
"People think it's cool," Pappalardo says. "But the blown-apart story is
over-simplified."
Pappalardo, who did his PhD thesis on the satellite, says there are too many
unanswered questions to call Miranda's case closed.
Pappalardo discovered the problems when he tried to understand how the
coronae - the formal name for Miranda's tortured bullseye patterns of
ridges, grooves, and jumbled terrain - could have formed by sinking blocks
of the reassembled moon.
For one thing, when Pappalardo studied the racetracks of concentric ridges
and grooves, they didn't look like features formed by compression. Instead,
it looked as if the moon's crust had been ripped apart.
The sawtooth patterns of ridges, so striking in Voyager's first closeups,
were likely created when blocks of icy crust fractured and tipped, like
books falling over on a bookshelf. And a close look at the ridges by
Pappalardo and others indicated that some are actually icy volcanoes.
Suddenly the whole picture changed. Instead of dense blocks sinking into the
crust, Miranda's features seemed to be formed by something rising up from
below.
Pappalardo says he sees evidence of rifting in the crust, much like that
caused in East Africa by upwelling of hot material in the Earth's mantle (to
picture this, think of the slowly rising blobs of molten wax inside a "lava
lamp"). In the case of Miranda, however, where present temperatures hover
around a frigid -335 degrees Fahrenheit, the rising material would have been
relatively warm ice, possibly a mixture of frozen water and ammonia or
methane.
Canyons formed by the rifting of Miranda's crust created the towering cliffs
visible in Voyager's images, says Pappalardo. And the fractured crust
allowed fresh ice to reach the surface, producing the bright chevron-shaped
feature.
With internal heating now the culprit, theorists realized it no longer was
necessary to invoke the process of destruction and re-assembly to explain
Miranda's bizarre features. In fact, even though such catastrophes likely
took place on Miranda and many other outer-planet satellites, they have
probably done little to shape their present-day appearances.
"I don't think we see any evidence of these events today," says Geologist
Bill McKinnon of Washington University of St. Louis. "The bodies just fall
back together, and you get a cratered ball" resembling Saturn's Mimas.
But that left the question of what else could have heated Miranda to create
its tortured landforms. The problem, says McKinnon, is that Miranda's small
size and relatively large surface area makes it difficult to heat up. "It's
hard to keep a sparrow warm," McKinnon says.
For that reason, McKinnon and others doubt that Miranda's geologic activity
could have been powered by the decay of radioactive elements, the heat
source that has helped fuel the Earth's geologic "engine."
For another possible source of heat, scientists look to tidal heating,
caused by a condition called a resonance, in which two satellites whose
orbits are synchronized so that they regularly line up on the same side of
their planet. Resonances create a gravitational tug of war among Jupiter's
large inner moons, causing their interiors to flex and heat up.
This tidal heating is what makes the Jovian moon Io a volcanic powerhouse,
and may have created an ocean of liquid water beneath the crust of Europa.
There are no such resonances between Miranda and the other Uranian
satellites today. But sharp-eyed theorists have calculated that resonances
could have existed in the distant past, as Miranda's orbit changed. The
result: A temporary heat-pulse that heated Miranda's interior just long
enough to produce the observed features. And then, nothing. After this burst
of activity, Miranda was left a work unfinished.
Or, as Pappalardo says, "Miranda is a world caught in the act of
differentiating."
How long ago did all of this happen?
Based on the number of craters counted within the youngest terrains (at the
centers of the coronae) Miranda's geologic activity may have continued until
as recently as half a billion years ago. But there is debate about that, and
about much else associated with Miranda. Even Pappalardo concedes that a
catastrophic impact might have played an important role in Miranda's
evolution. As McKinnon says flatly, "We don't really know what's going on."
A closer look at Miranda, on some future spacecraft mission, could change
that for good.
Copyright 2001, Space.com
===========
(10) CELESTIAL CATASTROPHES IN HUMAN PREHISTORY?
>From John Michael <jm@morien-institute.org>
Dear Benny,
I thought CCNet members might like to know about the following meeting
Wednesday October 17th 2001:
http://www.upennmuseum.com/pressreleases/forum.pl?msg=76
"Celestial Catastrophes" Program Oct. 17
From: University of Pennsylvania Museum of Archaeology and Anthropology
Date: 10/12/2001
Contact: Pam Kosty, Public Information Officer
PHYSICIST DR. ANTHONY PERATT TO PRESENT NEW FINDINGS THAT LINK ANCIENT ROCK
ART, STONEHENGE, TO
WORLDWIDE OBSERVATIONS OF UNUSUAL SPACIAL OCCURENCE
* * *
Scientist to Speak at University of Pennsylvania Museum Program
"Celestial Catastrophes in Human Prehistory?"
Wednesday, October 17, 6 p.m.
Philadelphia, PA-New Mexico physicist Dr. Anthony L. Peratt offers a
provocative new theory about the catastrophic "story" that many of the
world's petroglyphs, pictographs, rock carvings, rock paintings and even
monuments from antiquity may in fact be telling, when he speaks on "Talking
Rocks" at Celestial Catastrophes in Human Prehistory?, a special program in
the Harrison
Auditorium, University of Pennsylvania Museum of Archaeology and
Anthropology, Wednesday, October 17, 6 p.m.
The public program, which runs from 6 to 7:30 p.m. and includes discussants
from several departments in the University of Pennsylvania and the Museum,
is free. A reception with Dr. Peratt and the discussants, running from 7:30
to 8:30, is $20; $15 for Museum members. The number for more information or
to pre-register for the reception (through October 15) is 215/898-4890.
Basing his findings on new high technology experimental research, Dr.
Peratt, Associate Laboratory Directorate, Experimental Programs and
Simulation and Computing, Los Alamos National Laboratory, argues that
numerous rock art designs, and even the monument Stonehenge, can be linked
to the recording of a highly visible outer space event that occurred many
millennia ago. Dr. Jeremy Sabloff, the Williams Director, UPM; Dr. Harold
Dibble, Deputy Director, UPM; Dr. Robert Giegengack, Chairman, Earth and
Environmental Sciences at the University of Pennsylvania; and Dr. Charles
Alcock, Reese W. Flower Professor of Astronomy and Astrophysics at the
University of Pennsylvania, will respond.
Celestial Catastrophes in Human Prehistory? continues an occasional series,
co-sponsored by the University of Pennsylvania Museum, the Institute for
Environmental Studies, and the Center for Ancient Studies, on the impact of
catastrophic events on human history. Past programs
have examined the impact of volcanoes ("Explosive Volcanism," January 17,
2001), asteroids ("Impact Craters in Earth History" May 11, 2000 ) and
flooding ("Flooding the Black Sea: Noah and Early Agriculture?" October 14,
1999). The series is made possible through the generosity of Mr. and Mrs. A.
Bruce Mainwaring.
The University of Pennsylvania Museum of Archaeology and Anthropology is
dedicated to the study and understanding of human history and diversity.
Founded in 1887, the Museum has sent more than 350 archaeological and
anthropological expeditions to all the inhabited continents of the world.
With an active exhibition schedule and educational programming for children
and adults, the Museum offers the public an opportunity to share in the
ongoing discovery of humankind's collective heritage.
UPM is located at 33rd and Spruce Streets in Philadelphia. The Museum is
open Tuesday through Saturday, 10 a.m. to 4:30 p.m. and 1 to 5 p.m. on
Sundays; closed Mondays, holidays and summer Sundays from Memorial Day
through Labor Day. Museum admission donation is $5 adults; $2.50 senior
citizens and students with ID; free to Museum members, children under 6, and
University of Pennsylvania staff, students and faculty with a PENNcard, and
FREE Sundays, through May 19, 2002. Visit the Museum's website at
www.upenndot edu/museum or call (215) 898-4000 for general information.
# # #
TO THE PRESS: Additional information about Dr. Peratt's newest findings, and
a related color jpeg image from Dr. Peratt, are available upon request.
regards,
John Michael
===========
(11) SPACE COMES TO EDINBURGH
>From ESA Media Relations <ContactESA@esa.int>
Paris, 15 October 2001
Press Release
N054-2001
Space comes to Edinburgh
On 14 and 15 November, the city of Edinburgh will host the eighth
ministerial-level meeting of the European Space Agency's Council. The
ministers responsible for space activities in ESA's fifteen member states(1)
and Canada will be setting the course for Europe's space programmes for the
period ahead. They will be invited to endorse the next stages of a series of
ongoing programmes (Launchers, Space Science, Earth
Observation,Telecommunications, Satellite Navigation, Human Spaceflight
etc.), and also to commit to the start of new programmes that will keep
Europe at the forefront of space activities.
Surrounding this conference, the City of Edinburgh, with support from ESA
and the British National Space Centre (BNSC), is organising a programme of
space-related events in Edinburgh for people of all ages, including a
week-long festival of space activities for kids at the "Our Dynamic Earth"
visitor centre; "Europe in Space", a major new exhibition tracing three
decades of European cooperation in space at the City Art Centre; and the
Edinburgh Lecture Series on the theme of "Frontiers" from 6 November through
to February next year.
Hard to miss will be an 11-metre full-scale model of ESA's Envisat satellite
on display in front of Our Dynamic Earth from 13 October until 18 November.
Envisat, the world's largest and most sophisticated Earth observation
platform, is to be launched in early 2002 by Ariane 5 and will monitor
planet Earth, giving the first three-dimensional pictures of the processes
which shape the global environment.
On Thursday 18 October, ESA will celebrate "Space Day" in Edinburgh by
conferring on the city the "European Space City" award. ESA astronaut Claude
Nicollier, a veteran of four spaceflights and two spacewalks, will present
the official certificate to the Lord Provost of Edinburgh, the Rt. Hon. Eric
Milligan, at a ceremony at Our Dynamic Earth at 17:00.
ESA has recently created the "European Space City" award to honour a city
for exceptional contributions to the promotion of European space activities.
In conjunction with this award, ESA will launch an educational initiative
with the City of Edinburgh and schools in the Edinburgh area under which
classes will build the "Kid's Corner" web pages for ESA's portal. ESA's
objectives in creating this award are to foster a long-term relationship
with cities that are keen on space and to develop a network of "European
Space Cities".
During his day in Edinburgh, astronaut Claude Nicollier will return the
official tartan of the City of Edinburgh, carried into space last August, to
city officials. He will also have a "space lunch" with 20 young contest
winners and give a public talk in the evening.
To know more about all these activities, please contact:
Our Dynamic Earth, Deborah Lidgett, Tel:+44.(0)131.530.3508
City of Edinburgh, Jenni Steele, Tel:+44.(0)131.529.4427
BNSC, Jenny Haynes, Tel:+44. (0)20.7215.0806
(1) Austria, Belgium, Fnland, France, Denmark, Germany, Italy, Ireland, the
Netherlands, Norway, Portugal, Spain, Sweden Switzerland, and the United
Kingdom. Canada takes part in some projects under a cooperation agreement.
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