Keeping in mind falls on Jan. 3, and their types:
Lost City H5 (Oklahoma, US 1970)
Warrenton CO3 (Missouri, US 1903)
St. Marks EH5 (South Africa 1877)
2003 EH1 and St. Mark's EH5 a coincidence:)
And from the JPL toolkit, I checked out 138 years (1873 to 2010) of 2003 EH1 position:
1877 at 1.02 AU from Sun and 0.53 AU from Earth
1903 at 3.64 AU from Sun and 4.54 AU from Earth
1970 at 1.97 AU from Sun and 2.15 AU from Earth
And, if I rank proximity of 2003 EH1 for the 138 years, the top nine are the only ones under one AU from Earth, in date order. I find it interesting that 1877, the date of St. Marks EH5) is the second closest approach in the 138 years.
1877 0.52
1904 0.61
1915 0.85
1926 0.23
1937 0.67
1981 0.74
1992 0.56
2003 1.11
2004 3.77
For 138 years:
Average = 4.46
Sigma = 1.63
min. 0.23
max. 6.12
Rank in 138 years of closest approach to Earth (1926 was closest at 0.23 AU):
1877 (2)
1903 (55)
1970 (17)
So, please check out St. Marks EH5 as a footnote somewhere, and if you have nothing to do, Lost City H5 -which Elton had some potentially good additional comments...
I read your comments, and appreciate them, and also made a first pass at the e-preprint for which you gave the link. I am still left wondering, though after reading the following paragraphs from that paper, which conform that material seems to be distributed within the evolving orbit evenly (no dust peak at "parent body"), and that you are operating under theories of a too close for comfort Jupiter encounter perhaps causing a very significant ejection of material. If that is indeed the case, and if dust is well distributed which causes the "common" Quadrantids we see on a well timed morning, when we pass that perihelion point, what is to prevent a larger chunk here and there in the orbit escaping, being captured, and terminating on Earth, especially (not meant to be contradictory with the orbital well-distributed observation :)) on a year when the "main mass of the parent body", i.e. 2003 EH1", is nearest Earth, as the above conjecture?
Here are the comments from your good paper referenced that have me even further mulling this over, while the DUST distribution seems to have uniformized through the whole orbit in very short timing according to the paper and other sources, observers, etc., a disintegration event would likely still have any larger pieces nearer the main body, right? Paper:
"There is no evidence that the dust density increases near the comet position. Together with the distributions shown in Figure 4, this defines the distribution of dust in the stream in three dimensions. From that, a mass of about 1x1013 kg is calculated for grains in the range 10-6 to 1000 g [12]. This compares to earlier estimates of a factor of 10-100 less [references in 12], on account of a wider dispersion in q. That is significantly more dust than typically lost from a typical Jupiter-family comet in a single return (~1010 kg), and implies either a deposition for a period of ~ 1000 years, or debris from a recent cometary breakup.
The Quadrantid meteoroids are cometary in nature, given that they appear to be fragile with numerous flares from the sudden release of small fragments and relatively high penetration depths in Earth's atmosphere [13]. The meteors end at altitudes similar to those of Perseids (from 109P/Swift-Tuttle) and Lyrids (from C/Thatcher) and do not penetrate as deep as the higher density Geminid meteoroids, cometary dust that has been sintered in a low q orbit and is thought to be more representative of compact asteroidal dust (Figure 5)."
If you had any additional comments, that would be very interesting...!!! For example, a little dreaming if there were a relation: could St. Marks EH5, anhydrous, be an example of a proto-Venusian cometary object, remanent highly elliptical orbit later condemened mostly to the asteriod belt after some gravitational interaction? Does 2003 EH1 show water absorption peaks?
Saludos
Doug Dawn
Mexico
En un mensaje con fecha 12/22/2003 5:28:41 AM Mexico Standard Time, [EMAIL PROTECTED] escribe:
Asunto: [meteorite-list] re: Bootids (Quadrantids) meteor shower and 2003 EH1
Fecha: 12/22/2003 5:28:41 AM Mexico Standard Time
De: [EMAIL PROTECTED]
Para: [EMAIL PROTECTED]
Enviado por Internet
Hello Doug and others,
>1. I can't resist asking if anyone can correlate any Jan 3 or (Jan 4?)
falls,
>or there about. This should be a fresh research question.
I don't think it is likely that the Quadrantids produce meteorites. The
dynamic behaviour of these meteors points out that they consist of very
fragile material that destroys completely in the upper atmosphere.
Quadrantids do not penetrate deep into the atmosphere, their average
end-height is for example higher up than for Geminids.
The early part of the story of the identification of 2003 EH1 as the
possible parent of the Quadrantids (and as a dormant comet) is one of a
definite succes of amateur meteor observers, and I am happy to have played a
(minor) part in that. It used to be thought that the Quadrantids were a very
old stream, derived many thousands of years ago from comet Machholz therough
a series of orbital evolution events. It were detailed Quadrantid meteor
orbits obtained by our Dutch Meteor Society in 1995 (by means of
triangulation of photograpic and video records) which showed that this could
not be: the scatter in the orbits was much too small for that. The scatter
in fact suggested that the stream was not much older than 500 years or so.
So the link with Machholz was rejected and it was proposed that the real
parent was a still undiscovered dormant comet, hiding as a yet undiscovered
asteroid in an orbit closely resembling that of the meteor stream. I was
co-author to that paper:
Jenniskens P., Betlem H., De Lignie M., Langbroek M. and Van Vliet M.:
Meteor stream activity V. The Quadrantids, a very young stream. Astronomy &
Astrophysics 327 (1997), 1242-1252.
With the discovery of 2003 EH1, it now seems we were right. :-)
For those interested in more details on the link between 2003 EH1 and the
Quadrantids: a pdf of a paper to appear in WGN (J. International Meteor
Organization) by Peter Jenniskens with more info can be get at:
http://aio.arc.nasa.gov/~leonid/EH1.pdf
To return to your question: don't look for meteorites connected to 2003 EH1.
This celestial body does not likely provide us with meteorites: but it's
debris generates a spectacular short peak of meteors each year on January
4th. This peak is very sharp and high activity (up to 150/hr) last very
short, a few hours only. The stream is one of the most narrow streams in
existence, and together with the Geminids the richest annual stream. It is a
difficult stream to observe due to its short peak (which has to coincide
with your local pre-dawn hours, as in the evening the radiant of the stream
is too low in the sky) and general bad northern hemisphere weather early
January. We captured the peak in full glory from the Netherlands in 1995,
and that was quite an event!
- Marco
------
Marco Langbroek
Dutch Meteor Society (DMS)
Leiden, the Netherlands
52.15896 N, 4.48884 E (WGS 84)
[EMAIL PROTECTED]
http://home.wanadoo.nl/marco.langbroek
