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(meteorobs) Excerpts from "CCNet 130/2000 - 11 December 2000"
An interesting set of articles in this issue, not least of which, the
AUTHORITATIVE Brian Marsden weighing in on the Geminids' parent body!
Clear skies, ;>
Lew Gramer
------- Forwarded Message
From: Peiser Benny <B.J.Peiser@livjm.acdot uk>
To: cambridge-conference <cambridge-conference@livjm.acdot uk>
Subject: CCNet, 11 December 2000
Date: Mon, 11 Dec 2000 11:05:24 -0000
CCNet 130/2000 - 11 December 2000
--------------------------------
"The Geminids are a mystery. Most meteoroids that we know of come
from comets. They are set free by solar vaporization of [cometary]
ice. Geminid meteoroids, on the other hand, appear to come from 3200
Phaethon, an asteroid. We're not sure why an asteroid should have a
debris trail, but this one does."
--Brian Marsden, Minor Planet Center, 8 December 2000
(1) TWO DAYLIGHT FIREBALLS OBSERVED FROM SPAIN
Josep M. Trigo <trigo@exp.uji.es>
[...]
(3) 'LIFE-FROM-SPACE' BALLOON READY FOR LAUNCH IN INDIA
The Times of India, 11 December 2000
(4) THE BAFFLING METEOR SHOWER THAT SEEMS TO COME FROM A CURIOUS ASTEROID
NASA Science News for December 8, 2000
(5) MYSTERY OF THE FIREBALL FROM THE SKY DEEPENS
Concord Monitor, 7 December 2000
[...]
==================================================================
(1) TWO DAYLIGHT FIREBALLS OBSERVED FROM SPAIN
>From Josep M. Trigo <trigo@exp.uji.es>
Press release from the Spanish Fireball Network (SPMN):
http://www.spmn.uji.es/
Two impressive fireballs, probably of cometary origin, were observed from
Spain on November 28 and 29. Both events were of short duration and happened
in diurnal hours. As consequence our network only has collected eye witness
reports.
Initially our team thought in the artificial nature of both fireballs. In
fact, these events just remind us the 27th Nov. 1999 fireball caused by the
Chinese Shenzhou Long March rocket. The atmospheric path of this impressive
reentry was analysed by us the past year (for more details please see the
SPMN homepage). Despite of these first impressions, the trajectory data and
luminous path characteristics suggested us a solar system origin for both
fireballs. This suspicion was confirmed by several specialist in satellite
decays such as: Alan Pickup and Harro Zimmer. They inform us that no reentry
events were expected for these days on Spain.
At this moment we are still collecting data of the 28th November fireball.
It was observed at midday from several cities in Andalucia and the visual
reports suggest that its absolute magnitude was close to -15. At this moment
we have only poor reports but probably in the next weeks we can elucidate
its nature and origin.
November 29th fireball has been analysed in more detail. In fact, this event
was observed from Mallorca (Balearic Islands) by several eyewitnesses. High
quality trajectory data of the fireball was obtained by Francisco Saez
Isern, a experienced meteor observer member of the UMA team of the Mallorca
Astronomical Observatory (OAM). These high quality data were provided us by
Enric Coll showing that the fireball appeared in the evenfall at 16h41m31s
+-3s UTC. The fireball appeared from Mallorca close to the Moon and Venus,
the only celestial bodies visible at this time. The reported apparent
magnitude was -10 although probably it could have been more impressive in
the night sky. The fireball exhibited several flares along its trajectory.
At the end an impressive green flare signaled the full desintegration of the
incident body. The luminous trajectory and the ending flare suggests us a
cometary origin. Moreover, analysing the angular velocity and the apparent
trajectory in the sky we have strong evidences that this fireball was
produced by a late Leonid meteoroid.
Additional information and trajectory data can be obtained in our homepage.
We will be grateful with whoever provide us additional information on these
two big events.
********************************************
Josep M. Trigo-Rodrmguez / Jordi Llorca Piqui
SPANISH PHOTOGRAPHIC METEOR NETWORK (SPMN)
Institut d'Estudis Espacials de Catalunya (IEEC)
Dept. Astronomy & Astrophysics, Univ. of Valencia
Dept. Experimental Sciences, Univ. Jaume I
Dept. Inorganic Chemistry, Univ. Barcelona
SPMN homepage: http://www.spmn.uji.es/
E-mails: trigo@exp.uji.es / jllorca@kripto.qui.ub.es
*********************************************
==================================================================
(3) 'LIFE-FROM-SPACE' BALLOON READY FOR LAUNCH IN INDIA
>From The Times of India, 11 December 2000
http://www.timesofindia.com/111200/11hlth15.htm
HYDERABAD: A scientific balloon carrying a special payload that will find
out if life came from space, is all set for a midnight launch from the
national balloon facility here, scientists said.
Sixteen super cooled sterilised containers -- that from the heart of the
payload - will collect air samples from heights of 10 to 35 km and bring
them back eight hours later.
"A helicopter is standing by to recover the precious cargo seconds after the
balloon made the touch down," Pushapa Bhargava, former director of Central
for Cellular and Molecular Biology (CCMB) and one of the investigators of
this experiment, said.
The balloon is being launched from the National Facility run by the Tata
Institute of Fundamental Research, Mumbai, one of four such facilities in
the world.
Scientists said the balloon experiment is being carried out to confirm their
discovery of an unknown form of bacteria in air samples brought by a balloon
last April. "Exhaustive microbiological analysis" had then established that
the bacteria was a new strain never before recorded on earth, they said.
"It is tempting to speculate that these micro organisms came from space, but
their terrestrial origin cannot be ruled out", Bhargava said. (PTI)
Copyright 2000, Times of India
==================================================================
(4) THE BAFFLING METEOR SHOWER THAT SEEMS TO COME FROMA CURIOUS ASTEROID
>From NASA Science News for December 8, 2000
http://science.nasadot gov/headlines/y2000/ast08dec_1.htm
Most meteor showers are caused by comets, but the Geminid meteor shower,
which peaks next Wednesday morning, seems to come from a curious near-Earth
asteroid.
December 8, 2000 -- Early risers who venture outdoors before dawn next week
are in for a treat. The Geminid meteor shower peaks on Wednesday morning
when sky watchers could spot as many as 3 to 5 shooting stars every minute.
Geminids look like most meteors -- they tend to be fast-moving and yellow in
color. But there's something special about them. Other meteor showers happen
when Earth passes through the debris trail of a comet. Tiny bits of dust no
bigger than a grain of sand disintegrate high in our atmosphere and leave
behind dazzling streaks of light. But the parent of the Geminids isn't a
comet at all. It appears to be a curious near-Earth asteroid known as 3200
Phaethon.
"The Geminids are a mystery," says Brian Marsden of Harvard's Minor Planet
Center. "Most meteoroids that we know of come from comets. They are set free
by solar vaporization of [cometary] ice. Geminid meteoroids, on the other
hand, appear to come from 3200 Phaethon, an asteroid. We're not sure why an
asteroid should have a debris trail, but this one does."
Sky watchers first noticed the Geminids in the mid-1800's, but for more than
a century the shower's source was unknown. Then, in 1983, NASA's Infrared
Astronomy Satellite spotted a new asteroid: 3200 Phaethon. Astronomer Fred
Whipple quickly realized that Phaethon and the Geminid meteoroid stream
follow nearly identical orbits. They move around the Sun in a one and a
half-year elliptical path that stretches from inside the orbit of Mercury
outward to the asteroid belt.
Every year in mid-December when the Geminid meteor shower is active, Earth
is barely eight lunar distances (~0.021 AU) from Phaethon's orbit. That
makes Phaethon a "potentially hazardous" near-Earth asteroid (NEA).
In most respects Phaethon appears to be an ordinary NEA, says Marsden, but
it is remarkable because it comes so close to the Sun. Its distance from the
Sun ranges from 0.14 AU at perihelion to 2.4 AU at aphelion. "The small
aphelion distance would be unusual for a defunct comet," he explained.
Phaethon's sungrazing orbit might be responsible, in part, for the Geminids.
"You could argue that a lump of dusty ice on the surface of Phaethon was
uncovered at some point and then vaporized by solar heating," he speculated.
Such an event might produce meteoroids in the style of a comet.
Phaethon doesn't have a tail now and there's no evidence that jets of
vaporizing debris are pushing the asteroid around. Whatever liberated the
Geminid meteoroids probably happened long ago.
"The Geminid meteor shower is very stable from one year to the next," notes
Robert Lunsford, Secretary General of the International Meteor Organization,
"and there is no evidence for outbursts that follow close encounters between
Earth and Phaethon." The debris trail seems to be spread rather uniformly
around Phaethon's orbit -- another indicator that the meteoroids are old.
In July 1996 astronomers saw something in the asteroid belt that could be
relevant to the past experiences of 3200 Phaethon.
"Four years ago Eric Elst contacted us from the European Southern
Observatory and reported a strange object (now known as 'Elst-Pizarro' after
its discoverers)," recalled Marsden. "It had a tail, like a comet, but no
coma. We calculated an orbit and it seemed to be a perfectly ordinary minor
planet in the asteroid belt. Furthermore, we found some older images of it
from 1979 and '85. There was no tail in those photos and by 1997 the tail
Elst saw a year earlier was gone."
Despite its brief appearance as a comet look-alike, Elst-Pizarro is probably
an asteroid, says Marsden. "We may have been seeing a cloud of dust that was
ejected by an impact with another asteroid or, perhaps, a small ice deposit
became uncovered and vaporized."
Elst-Pizarro spends all of its time in the main asteroid belt where
asteroid-asteroid collisions are most likely to happen. Phaethon spends less
time there, but it does visit the asteroid belt every 17 months when it
reaches its farthest point from the Sun. A collision between Phaethon and
some smaller object in the asteroid belt might account for the Geminid
debris stream. Detailed studies of Geminid orbits, however, indicate that
the meteoroids more likely crumbled away while Phaethon was close to the
Sun. Once again, there's no clear solution to the Geminid riddle.
The mysterious Geminids will be on display Wednesday morning, Dec. 13th,
when the ongoing shower reaches its day-long peak. Most years stargazers in
rural areas can see as many as 140 Geminids per hour. That number will be
substantially reduced by the glare of a nearly-full Moon on Wednesday.
"The brutal moonlight will prevent us from enjoying the Geminids as much as
usual," laments Lunsford. "I would estimate that rates will average 20 to 30
per hour for most observers."
No matter where you live, the best time to watch will be during the hours
before dawn on Wednesday. Meteors will streak away from a point (called the
"radiant") in the constellation Gemini. Geminids can appear anywhere in the
sky, but their trails will point back toward the radiant, which will lie
some 60 degrees above the southern horizon at 4 am as seen from mid-northern
latitude observing sites.
Even if the 2000 Geminids produce fewer meteors than usual, they're still
worth watching. The morning sky this month features an array of bright stars
and planets including Jupiter, Saturn, Sirius, the constellation Orion, and
even the subtle Pleiades. A trip outdoors before breakfast on Wednesday is a
no-lose proposition (weather permitting!).
And if you see a smattering of Geminids, just remember, each and every one
is a bona-fide enigma -- baffling and dazzling in equal measure!
Tune in to SpaceWeather.com for more information about the ongoing Geminid
meteor shower.
==================================================================
(5) MYSTERY OF THE FIREBALL FROM THE SKY DEEPENS
>From Concord Monitor, 7 December 2000
http://www.concordmonitor.com/stories/front0400/salisbury_fireball.shtml
If Monday's fire wasn't caused by a meteorite, what was it?
By STEPHANIE HANES
Monitor staff
SALISBURY - Ron Baalke of NASA's Jet Propulsion Lab saw the story about the
meteorite in a small New Hampshire town online. It seemed a spectacular
occurrence - meteorites are rare to begin with, but it's unheard of to see
one land on Earth still burning. So, on his California computer, he
forwarded the news to a London-based electronic network that disseminates
information on catastrophic asteroids and cosmic disasters.
The "CCNet" published Baalke's post about the supposed Granite State
meteorite, and sky-minded scientists across the world read the news.
Salisbury, New Hampshire, was famous.
Since Paul Kornexl and Donna Ayoub saw a fireball plummet from the sky into
the woods behind their houses Monday evening, Salisbury and its potential
meteorite have gained worldwide attention. While Kornexl, Ayoub and her
husband, Dave, continued to scour the muddy ground yesterday for
extraterrestrial signs, scientists from New Mexico to Moscow - aided by the
more-familiar science of the Internet - were conjecturing on just what
happened behind quiet Hensmith Road.
The first report that had come out of Salisbury said a meteorite had landed
in the woods behind 129 and 137 (which are next to each other) Hensmith
Road. The blazing softball-sized object had started two small fires in the
dried leaves Monday evening, and neighbors had rushed to douse the flames.
"It's a little weird for my book," said the fire dispatcher Monday. "I've
never had anything drop out of the sky on my watch."
By the time firefighters arrived on scene the blaze was extinguished. But
the curiosity wasn't.
Kornexl had been standing next to his shed when he saw the fireball land.
"I was dumbfounded," he said.
The next day, when a scientist from the Christa McAuliffe Planetarium
examined the scene, and other experts pieced together the reported details,
the explanation of a meteorite seemed less and less plausible.
A meteorite would not have been burning when it hit the ground, scientists
said. It would have left a crater when it landed and it would not have come
in on an arc like residents described.
But the woods were deserted. Kornexl, who spent six years in the Army, said
the scene didn't fit with any weapon he knew of. And air control and
military officials said there was nothing overhead at the time.
So the question lingered. What sort of unearthly visitor had shown up in
Salisbury?
The conjectures started coming in yesterday morning. Robin Griffith, who
lives outside Houston, Texas, said the New Hampshire fireball was similar to
a flash of light she saw from her deck back in July.
"If it had streaked I would have thought it was a shooting star," she said.
But she added that her siting was exactly the same - she didn't see her ball
of light fall to the horizon.
"I don't believe mine was what y'all had," she said. She gave the name of a
scientist in Russia who had studied her incident. Andrei Ol'khovatov had
read the posting on CCNet and had asked her to get more information about
the New Hampshire incident.
Ol'khovatov had his own opinion. "It was probably not a meteorite," he wrote
in an e-mail, "but a geophysical meteor (high-speed ball lightning). I
investigate these events for some years."
Ol'khovatov's Web page has scores of information about incidents of
geographic meteors, what he describes as a rare type of electric atmospheric
discharge like ball lightning. He suggests TWA Flight 800 and other airline
disasters may have been caused by this natural phenomena. Salisbury's fire
could be just the latest incident.
Richard Spalding, a senior engineer at the Sandia National Laboratories in
New Mexico, a U.S. Department of Energy national security lab, had his own
theory. Apart from the lab, Spalding has studied flashes in the atmosphere -
of which meteors are one sort and lightning another.
"This particular article is reminiscent of quite a number of events I've
looked into in which people claim they've seen a fireball come all the way
to the ground," he said. "I think they are an electrical manifestation -
akin to lightning but with nothing to do with thunderstorms."
Spalding said evidence of this sort of event could be gained by analyzing
some leftover material at the site.
"It's quite possible there are some radioactive trace elements that are
formed by the ions," he said. The Ayoubs, he said, agreed to send him some
ground samples. "If found, there's no mistaking something very strange had
occurred. There's only one way those elements could be created. It requires
high energy radiation."
Scientists conjecturing on the Salisbury mystery got more information from
residents yesterday as more people came forward with reports of seeing the
fireball.
Phil Plait, who works at NASA's Goddard Space Flight Center in Maryland and
who developed the badastronomy.com Web site to clear up misconceptions about
his science, said he spoke to more Hensmith Road residents who saw the
flame.
"I really, strongly feel it's not a meteorite," he said after hearing the
residents' descriptions. "I, unfortunately, don't have a good alternative
explanation. Unless it was something thrown from a distance. Sometimes these
things are mysteries forever."
But if the bright light New Durham resident Ron Nordquist saw Monday night
was the same fireball, it couldn't have been an object simply thrown over
the trees.
Nordquist said he saw the glowing ball as he walked his dog around 5 p.m.
"It was like the brightest star you've ever seen," he said. "It was going
down instead of going across the sky. It seemed like it was going in slow
motion, even though it happened in seconds. I looked at the dog and I said
'did you see that?' "
Nordquist mentioned the site to his brother on the phone that night. It
wasn't until he read the paper that he made a connection.
"I got my map book and looked for Salisbury. And right away, when I saw M6
or whatever the page was, right away I started getting goose bumps. I looked
up New Durham, I looked at Salisbury. And I said to myself, 'my goodness,
I'd seen that.' "
The scientific search is still on.
Sandt Michener, a scientist at the planetarium, said while he still doesn't
believe the object was a meteorite, he thinks the incident is worth
investigating further.
"There are a lot of ideas, but it's just so many possibilities," he said.
"If it is a meteorite, or if it's something else, it's unusual enough to
merit an investigation."
) Concord Monitor and New Hampshire Patriot
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