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(meteorobs) meteorobs-digest V3 #318I'm out of the office today and will return on Friday, March 17th.
I'm out of the office today and will return on Friday, March 17th.
In the meantime, for any trouble you're experiencing with voicemail or telephone please report it directly to the Service Desk at x8301 or via e-mail to * ISD Service Desk. For other issues, you may contact my manager, Jack Marino at x8833. ~~~mlg~~~
>>> "meteorobs@jovian.com" 03/16/00 18:37 >>>
meteorobs-digest Thursday, March 16 2000 Volume 03 : Number 318
(meteorobs) Monitoring high sporadic rates -- call for observers
(meteorobs) Re: March 9th, 2000, Arkansas fireball
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Re: (meteorobs) Monitoring high sporadic rates -- call for observers
Re: (meteorobs) Mar 14/15 Meteor Observations From California
Re: (meteorobs) Monitoring high sporadic rates -- call for observers
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
(meteorobs) Yukon Meteorite May Provide 'New Window Into The Universe'
(meteorobs) Forward: NASA PRESS RELEASE
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
(meteorobs) [ASTRO] Scientists To Discuss Yukon Meteorite Tomorrow
(meteorobs) Excerpt from "CCNet LETTERS TO THE MODERATOR, 16 March 2000"
Re: (meteorobs) Monitoring high sporadic rates -- call for observers
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
(meteorobs) Excerpts from "CCNet, 15 March 2000"
(meteorobs) Fw: Yukon meteorite recovered!
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
(meteorobs) Meteor Activity Outlook March 17-23
----------------------------------------------------------------------
Date: Thu, 16 Mar 2000 07:19:23 -0500
From: Kim Youmans <ksyo@pinelanddot net>
Subject: (meteorobs) Monitoring high sporadic rates -- call for observers
- --------------1376673B2E469C541B55EC3E
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
It has been slowly becoming obvious that sporadic meteor rates have
been rather high for March this year. No fewer than 6 experienced
observers have reported higher than normal sporadic rates beginning late
in Febuary and continuing until the present time. To paraphrase Robert
Lunsford, sporadic rates in March are on the decline reaching a nadir
in April/May before climbing again in late June and July. To quote him
directly, "I'm not used
to seeing 10/hr this time of year!" I personally don't recall seeing
10/hr sporadics at all last March. This may just be a statiscal fluke
or random fluctuation in rates, but then again, without plenty of data,
there's no way to know.
I would like to urge all observers who can to get out over the next
three mornings and add their data to the pool. The full moon is fast
approaching, and only limited hours are left for pre-dawn observing.
The following periods are a very rough summary of the last few hours of
visual observing left before full moon:
Thursday morning March 16 3:30AM until twilight
Friday morning March 17 4:15AM until twilight
Saturday morning March 18 4:55AM until twilght
I'm not sure if Saturday morning will have enough useful observing time
at all.
The moon will be low enough on the horizon beginning at these times for
useful observations if
the observer faces away from it.
Times given are somewhat dependent on the observers longitude.
I also urge moon-proof radio observers to monitor sporadic rates and
post their data and their interpretations/comments on it.
It would also be good to hear from long-time observers and their
accounts of historical trends in March sporadic rates.
Kim S. Youmans
- --------------1376673B2E469C541B55EC3E
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<tt>It has been slowly becoming obvious that sporadic
meteor rates have been rather high for March this year. No fewer
than 6 experienced observers have reported higher than normal sporadic
rates beginning late in Febuary and continuing until the present time.
To paraphrase Robert Lunsford, sporadic rates in March are on the
decline reaching a nadir in April/May before climbing again in late June
and July. To quote him directly, "I'm not used</tt>
<br><tt>to seeing 10/hr this time of year!" I personally don't recall
seeing 10/hr sporadics at all last March. This may just be a statiscal
fluke or random fluctuation in rates, but then again, without plenty of
data, there's no way to know.</tt>
<br><tt> I would like to urge all observers who can to
get out over the next three mornings and add their data to the pool.
The full moon is fast approaching, and only limited hours are left for
pre-dawn observing. The following periods are a very rough summary
of the last few hours of visual observing left before full moon:</tt>
<p><tt>Thursday morning March 16 3:30AM until twilight</tt>
<br><tt>Friday morning March 17 4:15AM until twilight</tt>
<br><tt>Saturday morning March 18 4:55AM until twilght</tt>
<p><tt>I'm not sure if Saturday morning will have enough useful observing
time at all.</tt>
<br><tt>The moon will be low enough on the horizon beginning at these times
for useful observations if</tt>
<br><tt>the observer faces away from it.</tt>
<br><tt>Times given are somewhat dependent on the observers longitude.</tt>
<br><tt>I also urge moon-proof radio observers to monitor sporadic rates
and post their data and their interpretations/comments on it.</tt>
<p><tt>It would also be good to hear from long-time observers and their
accounts of historical trends in March sporadic rates.</tt>
<br><tt>Kim S. Youmans</tt>
<br>
<br> </html>
- --------------1376673B2E469C541B55EC3E--
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------------------------------
Date: Wed, 15 Mar 2000 16:57:38 -0800 (PST)
From: Robert Verish <bolidechaser@yahoo.com>
Subject: (meteorobs) Re: March 9th, 2000, Arkansas fireball
- --- Charlie <moonrock25@webtvdot net> wrote:
> Hi all:
>
> For whatever it's worth, this page has photos of the
> "impact site" of
> the March 9th fireball:
>
> http://freetimedot netfirms.com/fireball.html
>
> -Charlie Devine
>
> ----------
> For help, FAQ's and sub. info. visit:
> http://www.meteoritecentral.com/mailing_list.html
> ----------
>
>
__________________________________________________
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------------------------------
Date: Wed, 15 Mar 2000 23:09:36 EST
From: KevTK@aol.com
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
In a message dated 3/15/00 8:27:51 PM Eastern Standard Time,
bolidechaser@yahoo.com writes:
<< > For whatever it's worth, this page has photos of the
> "impact site" of
> the March 9th fireball:
> >>
I looked the site over and I see a big nothing.
All the photos show is the remnants of a brush fire (as a pro I've seen
hundreds). 200ft. from my observing site here in SI there just was a brush
fire - anybody want photos? :) The "crater" he shot could be simply the
holes caused by the boots of all the firefighters that was in the area
putting the fire out. The tracks could be the apparatus of the arriving
units. Even his timetable makes no sense, (quoting here):
8:00PM - someone sees a fireball
9:00 - 10:00PM - someone reports his house shook
11:30PM - a fire is reported
PLUS, the big point is that a meteorite landing will not start a fire. The
Peekskill meteorite went thru a car - why didn't the car ignite? A student
watch and filmed a meteorite land in Japan (I have the video) that one never
started a fire either. There have been NO reported fires by a meteorite that
I can find - EVER. Didn't happen in Arkansas either.
Kevin K
"I'm all for individuality...just as long as everyone does it."
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------------------------------
Date: Thu, 16 Mar 2000 00:13:33 EST
From: RRash62@aol.com
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
You should sent this to Art Bell radio show. They were on this last night and
think
it might be related to something of a UFO event. A farmer is reported to have
dug up
something with a backhoe.
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------------------------------
Date: Wed, 15 Mar 2000 21:51:48 -0800
From: Joshua <staff@meteors.com>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Meteorites are not hot enough to ignite a fire when they reach the ground.
om,
- -joshua
KevTK@aol.com wrote:
> In a message dated 3/15/00 8:27:51 PM Eastern Standard Time,
> bolidechaser@yahoo.com writes:
>
> << > For whatever it's worth, this page has photos of the
> > "impact site" of
> > the March 9th fireball:
> > >>
>
> I looked the site over and I see a big nothing.
> All the photos show is the remnants of a brush fire (as a pro I've seen
> hundreds). 200ft. from my observing site here in SI there just was a brush
> fire - anybody want photos? :) The "crater" he shot could be simply the
> holes caused by the boots of all the firefighters that was in the area
> putting the fire out. The tracks could be the apparatus of the arriving
> units. Even his timetable makes no sense, (quoting here):
> 8:00PM - someone sees a fireball
> 9:00 - 10:00PM - someone reports his house shook
> 11:30PM - a fire is reported
>
> PLUS, the big point is that a meteorite landing will not start a fire. The
> Peekskill meteorite went thru a car - why didn't the car ignite? A student
> watch and filmed a meteorite land in Japan (I have the video) that one never
> started a fire either. There have been NO reported fires by a meteorite that
> I can find - EVER. Didn't happen in Arkansas either.
>
> Kevin K
>
> "I'm all for individuality...just as long as everyone does it."
> To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
> http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
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------------------------------
Date: Thu, 16 Mar 2000 01:43:27 EST
From: RRash62@aol.com
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
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------------------------------
Date: Thu, 16 Mar 2000 11:01:13 +0100 (MET)
From: Sirko Molau <molau@informatik.rwth-aachendot de>
Subject: Re: (meteorobs) Monitoring high sporadic rates -- call for observers
Hi Kim,
> I would like to urge all observers who can to get out over the next
> three mornings and add their data to the pool. The full moon is fast
> approaching, and only limited hours are left for pre-dawn observing.
I would really like to join in with our video equipment, but weather in
March is unusually poor over here in Germany. So far I did not obtain even
a _single_ observation, and also Juergen catched only _one_ 3-hour cloud
gap in all of March so far. The forecast does not predict any improvement
for the next few days... :-(
Sirko
(little frustrated)
- --
**************************************************************************
* Dipl.-Inform. Sirko Molau * *
* RWTH Aachen, Lehrstuhl fuer Informatik VI * __ *
* Ahornstr. 55, D-52056 Aachen, Germany * " 2B v 2B " *
* * *
* phone: +49-241-8021615 * Shakespeare *
* fax : +49-241-8888219 * *
* email: molau@informatik.rwth-aachendot de * *
**************************************************************************
* www : http://www.informatik.rwth-aachendot de/I6/Colleagues/molau *
**************************************************************************
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------------------------------
Date: Thu, 16 Mar 2000 06:46:27 -0500
From: "Kim Hay" <kimhay@kingstondot net>
Subject: Re: (meteorobs) Mar 14/15 Meteor Observations From California
Hi Bob & the group
I am afraid the only meteors I have seen are the big fat white fluffy
snowflake design.
But it sure is nice to read that the rest of the group is out observing.
Clear skies (ya right)
Kim
***************************************************
Moonlight Cascade Observatory/BBS
44.28.28.9N 76.29.45.9W
VA3KDH
http://members.kingstondot net/kimhay
***************************************************
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------------------------------
Date: Thu, 16 Mar 2000 13:11:36 +0100
From: "exceld77" <excel@sioldot net>
Subject: Re: (meteorobs) Monitoring high sporadic rates -- call for observers
Hi!
It bothered me too, as I was seeing up to 15/h in the morning hours on
March 11/12, March 4/5 and March 5/6. Even the evening rates can reach
10/hr.
It is interesting that I always get a very strong hour between 23:00 and
00:00
local. Don't know why, but it goes up to 15/h. So far I haven't observed
the
'typical' March rates of 3 - 5/h.
Most of the meteors I see are faint, between +3 and +6 magnitude, I
rarely
get a negative magnitude meteor, perhaps one or two in 5 to 8 hours!! Can
anyone confirm this?
I won't be able to go out on any of these mornings as I am unfortunately
sick... ...but the forecast is bad anyway, cloudy with localised snow
showers.
So much for meteors...
Clear skies!
Jure A.
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------------------------------
Date: Thu, 16 Mar 2000 23:39:03 +0800
From: Stuart Saunders <stuart@ficnetdot net>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
I disagree.
The Peekskill meteor was white hot in the video, when it was very close to
ground. The fact that it did not ignite the car was probably because it hit
beside the taillight, not the petrol tank or soft trim. I have no doubt that it
could have set dry scrub alight had it landed on it. Not much dry scrub in NYC;
some scrub in Japan, but not usually dry.
It would be nice to have the god-like wisdom required to be able to make
absolute statements such as 'Meteorites don't start fires'.
Perhaps just tektites?
Joshua wrote:
> Meteorites are not hot enough to ignite a fire when they reach the ground.
>
> om,
> -joshua
>
> KevTK@aol.com wrote:
>
> > In a message dated 3/15/00 8:27:51 PM Eastern Standard Time,
> > bolidechaser@yahoo.com writes:
> >
> > << > For whatever it's worth, this page has photos of the
> > > "impact site" of
> > > the March 9th fireball:
> > > >>
> >
> > I looked the site over and I see a big nothing.
> > All the photos show is the remnants of a brush fire (as a pro I've seen
> > hundreds). 200ft. from my observing site here in SI there just was a brush
> > fire - anybody want photos? :) The "crater" he shot could be simply the
> > holes caused by the boots of all the firefighters that was in the area
> > putting the fire out. The tracks could be the apparatus of the arriving
> > units. Even his timetable makes no sense, (quoting here):
> > 8:00PM - someone sees a fireball
> > 9:00 - 10:00PM - someone reports his house shook
> > 11:30PM - a fire is reported
> >
> > PLUS, the big point is that a meteorite landing will not start a fire. The
> > Peekskill meteorite went thru a car - why didn't the car ignite? A student
> > watch and filmed a meteorite land in Japan (I have the video) that one never
> > started a fire either. There have been NO reported fires by a meteorite that
> > I can find - EVER. Didn't happen in Arkansas either.
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------------------------------
Date: Thu, 16 Mar 2000 11:27:00 -0500
From: Stop Light Pollution! <GLIBA@grovx3.gsfc.nasadot gov>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
In regards to meteorites landing hot, Stuart Saunders recently wrote:
> It would be nice to have the god-like wisdom required to be able to make
>absolute statements such as 'Meteorites don't start fires'.
FYI, it is common knowledge that most meteorites free fall, and actually cool
off during the end of their flights. Some have only been warm at best, and
others have had frost form on them shortly after being found after falling!
GWG
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------------------------------
Date: Thu, 16 Mar 2000 09:27:54 -0800 (PST)
From: Ron Baalke <baalke@zagami.jpl.nasadot gov>
Subject: (meteorobs) Yukon Meteorite May Provide 'New Window Into The Universe'
Donald Savage
Headquarters, Washington, DC March 16, 2000
(Phone: 202/358-1547)
Ann Hutchison
Johnson Space Center, Houston, TX
(Phone: 281/483-5111)
Jean-Claude Paradis
Natural Resources Canada, Ottawa, ON
(Phone: 613/992-9426)
RELEASE: 00-41
YUKON METEORITE MAY PROVIDE "NEW WINDOW INTO THE UNIVERSE"
A meteorite that exploded over a remote area of northwest
Canada in January may offer "a new window into the universe before
the solar system was created," said a NASA scientist who has begun
analyzing some of the meteorite fragments.
The very primitive composition and pristine condition of the
4.5-billion-year-old meteorite "offers us a snapshot of the
original composition of the entire solar system before the planets
formed," said Dr. Michael Zolensky, a cosmic mineralogist at
NASA's Johnson Space Center (JSC) in Houston. "It tells us what
the initial materials were like that went into making up the
Earth, the Moon and the Sun." The age of the solar system is
about 4.5 billion years.
"These meteorite fragments are of immense scientific value
and interest," said Dr. Richard Herd, Curator of National
Collections for the Geological Survey of Canada. "This rare find
potentially will contribute to a better understanding of the
nature of the universe." He added that finding previously
undetected compounds in the fragments will have implications for
both planetary and biological sciences worldwide.
The scientists described the fragments -- lumps of crumbly
rock with scorched, pitted surfaces -- as resembling partly used
charcoal briquettes: black, porous, fairly light and still
smelling of sulfur.
Several factors combined to make this meteorite a cosmic
bonanza for scientists. First, it is a carbonaceous chondrite, a
rare type of meteorite that contains many forms of carbon and
organics, basic building blocks of life. Carbonaceous chondrites,
which comprise only about 2 percent of meteorites known to have
fallen to Earth, are typically difficult to recover because they
easily break down during entry into Earth's atmosphere and during
weathering on the ground.
Zolensky said the last time a carbonaceous chondrite like
this fell to Earth and was recovered was 31 years ago. "This is
probably the only time in my career this will happen," he said.
The location and timing of the fireball also contributed to
the scientific value of the samples. The fragments are part of a
meteor that blew apart over a remote area of the Yukon Territory
the morning of Jan. 18, 2000. The resulting sonic booms startled
residents as far away as British Columbia and Alaska. The frozen,
snow-covered ground of the remote Yukon provided near-ideal
conditions for preservation, Herd said.
The finder, a local resident who has requested anonymity,
collected the fragments in clean plastic bags and kept them
continuously frozen. These are the only freshly fallen meteorite
fragments recovered and transferred to a laboratory without
thawing. Keeping the fragments continuously frozen minimized the
potential loss of organics and other volatile compounds in the
fragments.
About 2 pounds of meteorite fragments have been recovered so
far. Of those, Zolensky has about a pound of fragments provided
by the Canadian government and the University of Calgary. The
finder loaned them to the university and to the National Meteorite
Collection of the Geological Survey of Canada, Natural Resources
Canada (NRCan) in Ottawa, which provided the still-frozen samples
to JSC for study and analysis. NASA is working closely with NRCan
scientists and is providing results of the analysis to them. "We
are very sensitive to the fact that these are Canadian
meteorites," Zolensky said. Any future studies will be done in
cooperation with scientists worldwide.
Scientific analysis of the fragments has just begun. Tests
have been limited to two non-destructive activities: making a thin
section to analyze the mineralogy of the fragments, and measuring
induced radioactivity. Tests for induced radioactivity, which are
being carried out by Dr. David Lindstrom of JSC, measure the
object's exposure to space radiation. This can be used to
determine the size of the original meteoroid in space, estimates
of which range up to 50 feet in diameter, with a mass of more than
55 tons.
The next step in the study of the fragments will be baseline
analyses of the organics in the meteorite. This would require the
destruction of some samples, and negotiations are under way with
the finder for permission to do such tests.
"The nice thing about having a sample like this is that you
don't really know what you're going to find or where it's going to
lead," Zolensky said. "You can tuck samples away for the future
when new questions come along that people can't even think up
now."
- end -
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------------------------------
Date: Thu, 16 Mar 2000 12:42:14 -0500
From: Stop Light Pollution! <GLIBA@grovx3.gsfc.nasadot gov>
Subject: (meteorobs) Forward: NASA PRESS RELEASE
YUKON METEORITE MAY PROVIDE "NEW WINDOW INTO THE UNIVERSE"
Donald Savage
Headquarters, Washington, DC March 16, 2000
(Phone: 202/358-1547)
Ann Hutchison
Johnson Space Center, Houston, TX
(Phone: 281/483-5111)
Jean-Claude Paradis
Natural Resources Canada, Ottawa, ON
(Phone: 613/992-9426)
RELEASE: 00-41
YUKON METEORITE MAY PROVIDE "NEW WINDOW INTO THE UNIVERSE"
A meteorite that exploded over a remote area of northwest
Canada in January may offer "a new window into the universe before
the solar system was created," said a NASA scientist who has begun
analyzing some of the meteorite fragments.
The very primitive composition and pristine condition of the
4.5-billion-year-old meteorite "offers us a snapshot of the
original composition of the entire solar system before the planets
formed," said Dr. Michael Zolensky, a cosmic mineralogist at
NASA's Johnson Space Center (JSC) in Houston. "It tells us what
the initial materials were like that went into making up the
Earth, the Moon and the Sun." The age of the solar system is
about 4.5 billion years.
"These meteorite fragments are of immense scientific value
and interest," said Dr. Richard Herd, Curator of National
Collections for the Geological Survey of Canada. "This rare find
potentially will contribute to a better understanding of the
nature of the universe." He added that finding previously
undetected compounds in the fragments will have implications for
both planetary and biological sciences worldwide.
The scientists described the fragments -- lumps of crumbly
rock with scorched, pitted surfaces -- as resembling partly used
charcoal briquettes: black, porous, fairly light and still
smelling of sulfur.
Several factors combined to make this meteorite a cosmic
bonanza for scientists. First, it is a carbonaceous chondrite, a
rare type of meteorite that contains many forms of carbon and
organics, basic building blocks of life. Carbonaceous chondrites,
which comprise only about 2 percent of meteorites known to have
fallen to Earth, are typically difficult to recover because they
easily break down during entry into Earth's atmosphere and during
weathering on the ground.
Zolensky said the last time a carbonaceous chondrite like
this fell to Earth and was recovered was 31 years ago. "This is
probably the only time in my career this will happen," he said.
The location and timing of the fireball also contributed to
the scientific value of the samples. The fragments are part of a
meteor that blew apart over a remote area of the Yukon Territory
the morning of Jan. 18, 2000. The resulting sonic booms startled
residents as far away as British Columbia and Alaska. The frozen,
snow-covered ground of the remote Yukon provided near-ideal
conditions for preservation, Herd said.
The finder, a local resident who has requested anonymity,
collected the fragments in clean plastic bags and kept them
continuously frozen. These are the only freshly fallen meteorite
fragments recovered and transferred to a laboratory without
thawing. Keeping the fragments continuously frozen minimized the
potential loss of organics and other volatile compounds in the
fragments.
About 2 pounds of meteorite fragments have been recovered so
far. Of those, Zolensky has about a pound of fragments provided
by the Canadian government and the University of Calgary. The
finder loaned them to the university and to the National Meteorite
Collection of the Geological Survey of Canada, Natural Resources
Canada (NRCan) in Ottawa, which provided the still-frozen samples
to JSC for study and analysis. NASA is working closely with NRCan
scientists and is providing results of the analysis to them. "We
are very sensitive to the fact that these are Canadian
meteorites," Zolensky said. Any future studies will be done in
cooperation with scientists worldwide.
Scientific analysis of the fragments has just begun. Tests
have been limited to two non-destructive activities: making a thin
section to analyze the mineralogy of the fragments, and measuring
induced radioactivity. Tests for induced radioactivity, which are
being carried out by Dr. David Lindstrom of JSC, measure the
object's exposure to space radiation. This can be used to
determine the size of the original meteoroid in space, estimates
of which range up to 50 feet in diameter, with a mass of more than
55 tons.
The next step in the study of the fragments will be baseline
analyses of the organics in the meteorite. This would require the
destruction of some samples, and negotiations are under way with
the finder for permission to do such tests.
"The nice thing about having a sample like this is that you
don't really know what you're going to find or where it's going to
lead," Zolensky said. "You can tuck samples away for the future
when new questions come along that people can't even think up
now."
- end -
* * *
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------------------------------
Date: Thu, 16 Mar 2000 09:47:34 -0800
From: "Ed Majden" <epmajden@home.com>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Stuart Saunders wrote:
- ----- Original Message -----
From: Stuart Saunders <stuart@ficnetdot net>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
> I disagree.
> The Peekskill meteor was white hot in the video, when it was very
close to
> ground.
- ----------------------------------------------------------------------------
- ---
What the public has to become educated about is that the average end
point for a meteorite dropping fireball is around 18 km high. This is were
the meteor stops emitting light. When a meteor is passing through the
atmosphere only a thin portion of its surface is heated to vaporization
temperatures. This hot material is left behind or is ablated away from the
main mass. It does not have a chance to heat the main body of the meteorite
which is very cold. By the time the meteorite reaches the ground it may be
just warm to the touch or even cold!
It would most certainly NOT start a fire. This does not apply to very large
objects such as the type that blasted out Meteor Crater in Arizona. Such
objects hit the earths surface at hyper velocity exploding and vaporizing
the contact point. Such events are very rare indeed and would be a major
and catastrophic event if it occurred in a populated area. If large enough,
it could even possibly end most life on earth such as the impact event that
cause the dinosaur extinction. Peekskill was definitely not in this class
of fireball event. Not even close!!!
Ed Majden -
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------------------------------
Date: Thu, 16 Mar 2000 13:01:32 -0500
From: Lew Gramer <dedalus@latrade.com>
Subject: (meteorobs) [ASTRO] Scientists To Discuss Yukon Meteorite Tomorrow
- ------- Forwarded Message
From: Ron Baalke <BAALKE@KELVIN.JPL.NASAdot gov>
Date: Wed, 15 Mar 2000 22:56:48 GMT
Subject: [ASTRO] Scientists To Discuss Yukon Meteorite Tomorrow
March 15, 2000
Ann Hutchison
Johnson Space Center, Houston, TX
(Phone: 281/483-5111)
Release: J00-17
SCIENTISTS TO DISCUSS YUKON METEORITE TOMORROW
Planetary scientists from the U.S. and Canada will be available tomorrow
to discuss the meteorite that fell to Earth over a remote area of the
Yukon earlier this year.
Participating in the roundtable discussion will be Dr. Michael Zolensky
of JSC; Dr. Richard Herd of the Geological Survey of Canada; and Dr.
David Kendall of the Canadian Space Agency. The discussion will be held
at 3 p.m. CST in room 108 of JSC's Gilruth Center.
The meteor exploded in a fireball on January 18. Samples were collected
by a local resident and kept frozen, giving scientists the opportunity
to study meteorite fragments in a very pristine condition. Scientists
believe these 4.5-billion-year-old fragments will provide new insights
into the universe before the solar system was created.
NASA TV's Video File at 11 a.m. tomorrow will include footage of the
Yukon meteorite and of two similar meteorites that fell to Earth in
1969, as well as an interview with Zolensky. Replays will air at 2 p.m.,
5 p.m., 8 p.m. and 11 p.m. CST.
Journalists who plan to attend the discussion should contact the JSC
newsroom at 281-483-5111 as soon as possible unless they are already
badged for the Lunar and Planetary Sciences Conference currently being
held in the Gilruth Center. Plan to arrive early, as parking may be
limited.
- -END-
- ------- End of Forwarded Message
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------------------------------
Date: Thu, 16 Mar 2000 13:09:44 -0500
From: Lew Gramer <dedalus@latrade.com>
Subject: (meteorobs) Excerpt from "CCNet LETTERS TO THE MODERATOR, 16 March 2000"
- ------- Forwarded Message
From: Benny J Peiser <b.j.peiser@livjm.acdot uk>
To: cambridge-conference@livjm.acdot uk
Subject: LETTERS TO THE MODERATOR, 16 March 2000
Date: Thu, 16 Mar 2000 16:11:35 -0500 (EST)
LETTERS TO THE MODERATOR, 16 March 2000
- ---------------------------------------
[...]
(3) FASTEST SPINNING ASTEROID?
Petr Pravec <ppravec@asudot cas.cz>
[...]
===================
(3) FASTEST SPINNING ASTEROID?
>From Petr Pravec <ppravec@asudot cas.cz>
Charles F. Peterson <cfp@mcn.org> wrote:
> In terms of useful information about NEAs, it would seem that the
> velocity of the surface of the asteroid tells more than the rotational
> period. Am I correct?
> The surface of a 100 meter asteroid with a rotational (day/night)
> period of 10 minutes is not moving as fast at its equator as the
> surface of a one kilometer asteroid with a much longer rotational
> period. Surface velocity would tell something about origin and impact
> history, right? Day/night period seems to be an interesting but
> inconsequential artifact of the relationship of diameter to surface
> speed.
Actually, the most important information brought by the detection
of a fast asteroid spin is the ratio between centrifugal
acceleration and gravitational acceleration on the asteroid's
surface. The superfast spins tell us that the asteroids are
rotating under tension and therefore are monolithic. (I.e., not
gravitationally bound "strengthless" bodies.) The information
about asteroids internal structure is one of the main reasons why
to study asteroids spins. The fast day/night changes are less
important scientifically (but interesting for general public to
remember, thus they were pointed out in the press release so
widely distributed), but they are still relevant e.g. for
computation of temperature distribution on the asteroid surface.
Petr Pravec
- -----------------
CCNet-LETTERS is the discussion forum of the Cambridge-Conference
Network. Contributions to the on-going debate about near-Earth objects,
the cosmic environment of our planet and how to deal with it are welcome.
The fully indexed archive of the CCNet, from February 1997 on,
can be found at http://abob.libs.ugadot edu/bobk/cccmenu.html
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------------------------------
Date: Fri, 17 Mar 2000 01:15:50 -0500
From: Kim Youmans <ksyo@pinelanddot net>
Subject: Re: (meteorobs) Monitoring high sporadic rates -- call for observers
- --------------E615DA4ABC9E0E7DE082273C
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Hello Sirko,
>So far I did not obtain even a _single_ observation, and also Juergen catched
only _one_ >3-hour cloud gap in all of March so far. The forecast does not
predict any improvement
>for the next few days... :-(
That *is* extremely unfortunate, Sirko, as video observations would have
been perhaps the best data format for confirming the higher rates. I know the
feeling, just when I became able to resume observing here, the weather turned
bad! Perhaps the post full moon period will be clearer, but by then this
anamoly may have abated. :( It will be interesting, however, to see
a list of observers reports for March when such a list becomes available, most
likely at the NAMN website early in April.
Clearer skies
Kim
Sirko Molau wrote:
> Hi Kim,
>
> > I would like to urge all observers who can to get out over the next
> > three mornings and add their data to the pool. The full moon is fast
> > approaching, and only limited hours are left for pre-dawn observing.
>
> I would really like to join in with our video equipment, but weather in
> March is unusually poor over here in Germany. So far I did not obtain even
> a _single_ observation, and also Juergen catched only _one_ 3-hour cloud
> gap in all of March so far. The forecast does not predict any improvement
> for the next few days... :-(
>
> Sirko
> (little frustrated)
>
> --
> **************************************************************************
> * Dipl.-Inform. Sirko Molau * *
> * RWTH Aachen, Lehrstuhl fuer Informatik VI * __ *
> * Ahornstr. 55, D-52056 Aachen, Germany * " 2B v 2B " *
> * * *
> * phone: +49-241-8021615 * Shakespeare *
> * fax : +49-241-8888219 * *
> * email: molau@informatik.rwth-aachendot de * *
> **************************************************************************
> * www : http://www.informatik.rwth-aachendot de/I6/Colleagues/molau *
> **************************************************************************
>
> To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
> http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
- --------------E615DA4ABC9E0E7DE082273C
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
Hello Sirko,
<p><tt>>So far I did not obtain even a _single_ observation, and also Juergen
catched only _one_ >3-hour cloud gap in all of March so far. The forecast
does not predict any improvement</tt>
<br><tt>>for the next few days... :-(</tt>
<p><tt> That *is* extremely unfortunate, Sirko, as video observations
would have been perhaps the best data format for confirming the higher
rates. I know the feeling, just when I became able to resume observing
here, the weather turned bad! Perhaps the post full moon period will
be clearer, but by then this anamoly may have abated. :( It will
be interesting, however, to see</tt>
<br><tt>a list of observers reports for March when such a list becomes
available, most likely at the NAMN website early in April.</tt>
<br><tt>Clearer skies</tt>
<br><tt>Kim</tt>
<br>
<br>
<p>Sirko Molau wrote:
<blockquote TYPE=CITE>Hi Kim,
<p>> I would like to urge all observers who can
to get out over the next
<br>> three mornings and add their data to the pool. The full moon
is fast
<br>> approaching, and only limited hours are left for pre-dawn observing.
<p>I would really like to join in with our video equipment, but weather
in
<br>March is unusually poor over here in Germany. So far I did not obtain
even
<br>a _single_ observation, and also Juergen catched only _one_ 3-hour
cloud
<br>gap in all of March so far. The forecast does not predict any improvement
<br>for the next few days... :-(
<p>Sirko
<br>(little frustrated)
<p>--
<br>**************************************************************************
<br>* Dipl.-Inform. Sirko Molau
*
*
<br>* RWTH Aachen, Lehrstuhl fuer Informatik VI *
__ *
<br>* Ahornstr. 55, D-52056 Aachen, Germany
* " 2B v 2B "
*
<br>*
*
*
<br>* phone: +49-241-8021615
*
Shakespeare *
<br>* fax : +49-241-8888219
*
*
<br>* email: molau@informatik.rwth-aachendot de
*
*
<br>**************************************************************************
<br>* www : <a href="http://www.informatik.rwth-aachendot de/I6/Colleagues/molau">http://www.informatik.rwth-aachendot de/I6/Colleagues/molau</a>
*
<br>**************************************************************************
<p>To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
<br><a href="http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html">http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html</a></blockquote>
</html>
- --------------E615DA4ABC9E0E7DE082273C--
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------------------------------
Date: Thu, 16 Mar 2000 11:52:04 -0800
From: Dave English <prospector@sd.znet.com>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
FYI Stuart, any time reports of glowing meteorites make the news or
have resurfaced from history (RE: the discussion about the 1885
meteorite that fell in Mexico, almost hitting a person and was reported as
glowing in the ground, it can be found on 18/02/99 06:14 Dav and on
18/02/99 08:05 Dav in the monthly meteorobs archives), they are
disregarded out-of-hand because they don't fit preconceived notions of desk
jockies who haven't ever seen a meteorite hit the ground and been there
within a minute or two. In heat treating iron and giving it a temper, the
trick is to allow the heat from parts not exposed to the cooling water or oil
(including thick, internal parts) to reheat the iron which can take a little
time depending on the thickness of the iron. The discussion in Feb. '99 was
almost all against glowing meteorites, but I can see where some meteorites
can have frost on them from the cold entry while others, particularly
larger iron meteorites, can glow from internal heat that reheated the
surfaces which may indeed cool off during the free flight. Few here agree
with me as evidenced by the Feb. '99 discussion.
Dave English
Oceanside, California
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------------------------------
Date: Thu, 16 Mar 2000 16:46:29 -0500
From: Lew Gramer <dedalus@latrade.com>
Subject: (meteorobs) Excerpts from "CCNet, 15 March 2000"
- ------- Forwarded Message
From: Benny J Peiser <b.j.peiser@livjm.acdot uk>
To: cambridge-conference@livjm.acdot uk
Subject: CCNet, 15 March 2000
Date: Wed, 15 Mar 2000 09:12:05 -0500 (EST)
CCNet, 33/2000 - 15 March 2000
- ------------------------------
QUOTE OF THE DAY
"The NASA satellite conducting the first-ever close-up study of an
asteroid will be renamed to honor Dr. Eugene M. Shoemaker, a
legendary geologist who influenced decades of research on the role
of asteroids and comets in shaping the planets. The Near Earth
Asteroid Rendezvous (NEAR) spacecraft, currently orbiting asteroid
433 Eros more than 145 million miles from Earth, will now be known
as NEAR Shoemaker."
-- NASA, press release 14 March 2000
(1) NEAR SHOEMAKER: NASA RENAMES NEAR SPACECRAFT IN HONOUR OF
GENE SHOEMAKER
NASANews@hq.nasadot gov
(2) GLIMPSES INTO EROS' SHADOWS
Ron Baalke <baalke@jpl.nasadot gov>
[...]
(5) ANGULAR MOMENTUM TRANSFER IN OBLIQUE IMPACTS
M. Yanagisawa*) & S. Hasegawa, UNIVERSITY OF ELECTROCOMMUNICATION
[...]
(8) FASTEST SPINNING ASTEROID?
Charles F. Peterson <cfp@mcn.org>
[...]
=================================================================
(1) NEAR SHOEMAKER: NASA RENAMES NEAR SPACECRAFT IN HONOUR OF
GENE SHOEMAKER
>From NASANews@hq.nasadot gov
Donald Savage
Headquarters, Washington, DC March 14, 2000
(Phone: 202/358-1547)
Mike Buckley
Johns Hopkins University Applied Physics Laboratory, Laurel, MD
(Phone: 240/ 228-7536)
RELEASE: 00-38
NASA RENAMES NEAR SPACECRAFT FOR
PLANETARY SCIENCE PIONEER GENE SHOEMAKER
The NASA satellite conducting the first-ever close-up study of an
asteroid will be renamed to honor Dr. Eugene M. Shoemaker, a legendary
geologist who influenced decades of research on the role of asteroids
and comets in shaping the planets. The Near Earth Asteroid Rendezvous
(NEAR) spacecraft, currently orbiting asteroid 433 Eros more than 145
million miles from Earth, will now be known as NEAR Shoemaker.
"Gene Shoemaker was an inspirational, charismatic pioneer in the field
of interplanetary science," said Dr. Carl B. Pilcher, Director of Solar
System Exploration at NASA Headquarters, Washington, DC. Pilcher
announced the new name today during the Lunar and Planetary Science
Conference in Houston. "It is a fitting tribute that we place his name
on the spacecraft whose mission will expand on all he taught us about
asteroids, comets and the origins of our solar system. "
Shoemaker died in a 1997 car accident in the Australian outback while
on an annual study of asteroid impact craters. With his wife and
research partner, Carolyn, Shoemaker was part of the leading comet
discovery team of the past century, perhaps most famous for finding the
comet (Shoemaker-Levy 9) that broke up and collided with Jupiter in
1994.
He was an expert on craters and the impacts that caused them.
Shoemaker's work on the nature and origin of Meteor Crater in Arizona
in the 1960s laid the foundation for research on craters throughout the
solar system. He also established the lunar geological time scale that
allowed researchers to date the features on the moon's surface.
Though he never realized his dream of tapping a rock hammer on the
moon, Shoemaker taught Apollo astronauts about craters and lunar
geology before they left Earth. Last year, when NASA's Lunar Prospector
spacecraft crashed on the Moon in an experiment at the end of its
mission, a small vial of Shoemaker's ashes, carried aboard the
spacecraft, was scattered on the lunar surface.
Shoemaker was a key member of the 1985 working group that first studied
the NEAR mission, defining its science objectives and designing a
conceptual payload. Many of the group's recommended instruments were
included in the actual spacecraft, which only a month into its yearlong
orbit of Eros is already returning fascinating data on the asteroid's
surface and geology.
The first in NASA's Discovery Program of low-cost planetary missions,
NEAR launched from Cape Canaveral Air Station, FL, on Feb. 17, 1996.
After a four-year journey that included flybys of Earth (Jan. 1998) and
asteroids Mathilde (June 1997) and Eros (Dec. 1998), NEAR began
orbiting Eros on Feb. 14, 2000. The car-sized spacecraft will observe
the asteroid from various distances -- coming within several miles of
the surface -- before the mission ends in February 2001. The Johns
Hopkins University Applied Physics Laboratory in Laurel, MD, designed
and built the NEAR spacecraft and manages the mission for NASA's Office
of Space Science.
EDITORS NOTE: Images and information on the NEAR mission are
available at: http://near.jhuapldot edu
Information on Eugene Shoemaker is available at:
http://wwwflag.wr.usgsdot gov/USGSFlag/Space/Shoemaker/GeneObit.html
=================================================================
(2) GLIMPSES INTO EROS' SHADOWS
>From Ron Baalke <baalke@jpl.nasadot gov>
NEAR image of the day for 2000 Mar 14
http://near.jhuapldot edu/iod/20000314/index.html
Glimpses into Eros' shadows
This image mosaic, showing Eros' saddle and a shadowed feature to its
left, was taken from a distance of 204 km (127 miles). In this picture
features as small as 20 meters (65 feet) are visible. This is the best
view to date of this area. The sun is coming from the northeast
illuminating a shadowed feature that consists of three large craters
situated adjacent to each other. The two largest are each about 4-5 km
(2-3 miles) across. Because the sun is very low with respect to these
craters, even small topographic features cast long shadows, making them
easier to see. As a result, several boulders can be distinguished,
ranging from about 50 to 100 meters in diameter, on the crater walls.
The saddle, on the right of the mosaic, is relatively smooth, with
few impact craters, and has several grooves running across it. At the
top of the saddle are several curved grooves that are brighter than the
surrounding surface. Unusual brightness patterns are also visible in
the crater at the top left of the mosaic. The walls of the crater
appear to be more reflective and its floor less reflective than nearby
parts of the asteroid.
- - --------------------------------------------------------
Built and managed by The Johns Hopkins University Applied Physics
Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in
NASA's Discovery Program of low-cost, small-scale planetary missions.
See the NEAR web page at http://near.jhuapldot edu for more details.
=================================================================
(5) ANGULAR MOMENTUM TRANSFER IN OBLIQUE IMPACTS
M. Yanagisawa*) & S. Hasegawa: Angular momentum transfer in oblique
impacts: Implications for 1989ML. EARTH PLANETS AND SPACE, 1999,
Vol.51, No.11, pp.1163-1171
*) UNIVERSITY OF ELECTROCOMMUN,1-5-1 CHOFUGAOKA,CHOFU,TOKYO
1828585,JAPAN
We conducted 10 shots of high-velocity oblique impact experiments
(1.95-3.52 km/s) using nylon projectiles and spherical mortar targets.
Large craters were formed, but these targets were not disrupted by the
impacts. We then calculated the efficiencies of momentum transfer from
the projectile to the post-impact target for each experiment. The
efficiencies of angular momentum transfer from the translational motion
of the projectiles to the rotation of the post-impact targets were also
derived. A representative efficiency of angular momentum transfer was
calculated to be 0.17 for random successive collisions. The efficiency
was applied to an equation expressing the precession angle of
asteroids. It is shown that 1989ML, target of Japan-US
asteroid-sample-return-mission (MUSES-C) would be tumbling. Copyright
2000, Institute for Scientific Information Inc.
=============================
* LETTERS TO THE MODERATOR *
=============================
(8) FASTEST SPINNING ASTEROID?
>From Charles F. Peterson <cfp@mcn.org>
In terms of useful information about NEAs, it would seem that the
velocity of the surface of the asteroid tells more than the rotational
period. Am I correct?
The surface of a 100 meter asteroid with a rotational (day/night)
period of 10 minutes is not moving as fast at its equator as the
surface of a one kilometer asteroid with a much longer rotational
period. Surface velocity would tell something about origin and impact
history, right? Day/night period seems to be an interesting but
inconsequential artifact of the relationship of diameter to surface
speed.
- ----------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
- ----------------------------------------
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please contact the moderator Benny J Peiser <b.j.peiser@livjm.acdot uk>.
Information circulated on this network is for scholarly and
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------------------------------
Date: Thu, 16 Mar 2000 16:46:44 -0500
From: Mark Davis <MeteorObs@charlestondot net>
Subject: (meteorobs) Fw: Yukon meteorite recovered!
Space Science News for March 16, 2000
Fragments of a meteor that exploded over the Yukon in January, 2000, have
been collected and turned over to Canadian and NASA scientists for
analysis. The find is potentially the most important recovery of a rock
from space in at least 31 years. FULL STORY at
http://spacescience.com/headlines/y2000/ast16mar_1.htm
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------------------------------
Date: Thu, 16 Mar 2000 17:38:24 -0500
From: Lew Gramer <dedalus@latrade.com>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
Hi, folks, I've been reading this thread with some interest.
Dave English wrote:
>can have frost on them from the cold entry while others, particularly
>larger iron meteorites, can glow from internal heat that reheated the
>surfaces which may indeed cool off during the free flight. Few here
>agree with me as evidenced by the Feb. '99 discussion.
Dave, what is the mechanism exactly, which you are proposing would heat the
inside of even a pure iron-nickel meteoroid? After all, such objects wouldn't
be substantially heated by the near-Earth environment, I don't think. (Again,
lunar surface temperatures don't exceed 120oC or so - not hot enough to glow,
I don't believe.) And the brief exposure to frictional heating as a particle
entered Earth's atmosphere would SEEM to be too brief to cause much internal
heating: consider that most fireballs, even meteorite dropping ones, aren't
visible for more than a few tens of seconds, are they? And as Ed Majden very
correctly points out, much of that heating is rapidly dissipated by ablation
and vaporization from the surface of the meteoroid...
I'm no metallurgist, but that sounds like a very different circumstance from
the deliberate heating of a block of iron to temper it. So even if there *is*
reliable evidence that ground-burning meteorites have been observed, then the
question really becomes "How COULD this be true?"
Of course, I DEFINITELY agree with the statement that data should never be
thrown out because it doesn't fit accepted theories... However, one of the
key elements in any scientific investigation seems to be knowing what data
can be reliably included - and what data probably cannot.
As an example of this, we frequently hear reports of fireballs which "arced
across the sky", "landed just over the next ridge", "split in two and forked"
and other physically very unlikely descriptions: I understand these are gen-
erally discounted not just by "desk jockies", but by folks who make it their
business (and pleasure) to verify, hunt down, recover and study meteorites.
Clear skies all!
Lew Gramer
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------------------------------
Date: Fri, 17 Mar 2000 11:14:33 +1100 (EST)
From: Rob McNaught <rmn@aaocbn.aaodot gov.au>
Subject: Re: (meteorobs) Re: March 9th, 2000, Arkansas fireball
There is no record of Peekskill just before it hit the ground, so there is
no way of knowing just how hot is was. It is only a very small surface
region that is ablating when the fireball is visible and the amount of
heat that transfers to the interior is relatively small. The interior
is very cold (can't remember how cold, but well sub zero). The heat
affected region of a meteorite comprises the millimeter or so of
solidified fusion crust, the remnant of the final ablation and about
1cm below that. The interior is not physically affected by the
atmospheric flight. As a meteorite can take a minute or more to fall
to the ground after the ablation ends (the fireball "goes out"), and
the frictional heating is considerably less that the previous temperature
of ablation, the body cools. There is no compelling evidence of a
meteorite ever having caused a fire, and there are many occurrences of
meteorites found soon after fall in dry hay, or on a frozen lake
surface. Whilst some meteorites will transfer more heat to the interior
than others, particularly iron meteorites with very low trajectories that
might ablate for tens of seconds, there is still little reason to
believe normal meteorites could start fires. Big events can start fires
due to the thermal IR emitted from the fireball, but here we are talking
of a very different phenomenon.
Cheers, Rob
Robert H. McNaught
rmn@aaocbn.aaodot gov.au
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------------------------------
Date: Thu, 16 Mar 2000 16:34:13 -0800
From: Robert Lunsford <lunro.imo.usa@prodigydot net>
Subject: (meteorobs) Meteor Activity Outlook March 17-23
The moon will be full Monday the 20th placing a damper on meteor
observing this week. There is a small window of dark skies available for
morning observers on Friday and Saturday mornings but the moon will
still be up during morning twilight starting on Sunday. Starting
Wednesday the evening hours begin to get a small period of dark skies as
the moon passes its full phase and does not rise until after the end of
evening twilight.
The only radiant active during the evening will be the Virginids. For
Tuesday night the center of the radiant will be located at 12:36 -02
which is close to the famous double star Porimma, also known as Gamma
Virginis. The radiant is low in the east during the early evening so any
activity from this radiant is remote.
Observers in the Southern Hemisphere and the tropics can also try to
watch out on Friday and Saturday mornings for the Delta Pavonids now
located near 19:14 -60 and the Gamma Normids from 16:20 -51. Both of
these radiants produce swift meteors with geocentric velocities of 60
and 56 km/sec.
It's a shame that the moon is now interfering as recent sporadic rates
have seemed to be better than normal. It will be interesting to see
during the last week of the month (when the moon is less of a nuisance)
if this trend continues or if rates are a more normal 2-3 an hour during
the evening hours and 5-6 an hour during the morning hours.
Clear Skies!
Robert Lunsford
AMS Visual Coordinator
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End of meteorobs-digest V3 #318
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