Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P
Hi, Pete, Your message came just in time. I was typing a snide remark about the Hematitic Lump From Mars. (Somebody forward to this guy Göran Axelsson's picture of the identical tone rock in Sweden at a church, and explain to the guy that he got God's message all mixed up -- he's supposed to use his rock as the bell for his church, not sell it on eBay!) What bothers me about Comet 73P is this: It can't be a new comet (even though we discovered it in 1930). The orbit is too stable for the comet to have recently been thrown in there. It's been around for centuries, probably millennia, in this same orbit. Yet, it has unraveled so quickly and easily. Once it started to come apart, sometime between 1990 and 1995, it has split, re-split, fractured. If you go back and read the earliest studies this pass, the authors clearly expected that whatever splits had occured at the time they wrote to be the extent of splitting when they passed the Earth. Three fragments would be visible, they said. Whoops, make that six fragments. Uh-oh, make that 9, 12, 30. I'm not making fun of the researchers, but our experience of split comets is that this disintegration takes a while. 73P has just gone to hell overnight. It must be very, very weak, they say. OK, BUT... If it's that weak, what has been holding it together for the last 75 years (and for centuries before that)? Thermal stress is pegged as the likely culprit for the breakup, but it's been exposed to the Sun for a long time. How could it have survived so long if it was this fragile? My guess answer is that the fragile material was probably adhered to something that wasn't fragile, like a small rocky core. This small dark object would have been completely shielded from the Sun by the weak porous fluffy ices that surrounded it and made up the outer body of the comet. But once a good chunk of those ices cracks off from a tiny impact or from thermal stress, it exposes a portion of the dark rock core to sunlight; the rock warms and more fragments of icy fluff soon come loose. They're too small to survive and rapidly break up in a cascade of fragments, as we've seen. A bare dark rock object is left behind in an orbit similar to the other fragments, but it's too distant to be detected... yet. I'm looking forward to the discovery of a small Earth-crossing asteroid in 2011, 2016, 2022 with an orbit very like Comet 73P! It would not be a big one. The pre-breakup 73P nucleus was only 1000-1200 feet in diameter; a core is unlikely to be more than a few hundred feet across (30 to 80 meters), I hope, instead of 400 meters. Despite the fact that meteor showers are so showy, no fall has ever been associated with them. Only one fall was ever witnessed during a meteor shower and recovered, and it was an iron, a complete coincidence. The biggest fragments in a meteor shower are smaller than a pea, moving very fast, and in for a short bright ride, then Pffft! Small junk never makes it through the atmosphere. Predicting future meteor shower orbits is the most thankless job in number crunching. Some people like it for that very reason. Every little piece of cometary material is capable of puffing little jets of gas; every little jet is a thrust; every thrust alters the precise orbit somewhat; the thrusts go on for months with progressive orbital changes, like ion engines. Some jets are on rotating bodies, so the thrusts are like pinwheel jets, pushing this way then that way. To quote Charlton Heston in Planet of the Apes, It's a madhouse! A madhouse! How spectacular a close comet approach is depends not only on how close but on how big. The close approach of a really big fresh long-period comet is probably the most spectacular thing that is visible in the sky, apart from a Type II supernova 700 light years away. We haven't had one really spectacular one for over a century and a half, but the century before that was blessed with some giant apparitions, as they are called, in 1729 and 1744, and the 19th century had flashier big meteor showers than the 20th. Maybe we're due for one. As for people who worry about close approaches, here's a table of the 20 closest approaches of comets that were discovered after 1700 (although some historical close approaches are included in the list), courtesy of Harvard http://cfa-www.harvard.edu/iau/lists/ClosestComets.html One of the brightest recent ones is Hyakutake in 1996 and it was a really fine sight. Comet 73P is on the list at Number Ten (in 1930 when it was discovered). I added the distance to the Moon for comparison, and in all this time, nothing has gotten closer than six times the Moon's distance. I say, let's keep it that way. Distance Date (TT) Permanent designation (AU) 0.0026 Distance to the Moon 0.0151 1770 July 1.7 D/1770 L1 (Lexell) 0.0229 1366 Oct. 26.455P/1366 U1 (Tempel-Tuttle) 0.0312 1983 May 11.5 C/1983 H1 (IRAS-Araki-Alcock) 0.0334837 Apr.
Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P
Sterling, Stable Orbit for Millennia for 73P? Not a snowball's chance in errr,, the hot box (ref.: baseball play, a.k.a. a rundown in the pickle)! The similar basic mechanism that delivers meteorites to us has made this a very Hot comet in its recent passes. It has several encounters with Jupiter over the last 100 years which have probably significantly tagged it out and knocked its orbit silly, not to mention Earth, too, which hits it when it is nice and soft. In 1965 it passed just a 0.25 AU from Jupiter and that is a pretty deadly thing - with accelerations, and that is just one of the large examples. This comet pile currently has an aphelion of 5.2- AU an itsy bit inside of Jupiter's (5.2+ AU) orbit, and a perihelion of 0.94 AU just inside Earth's (1.0 AU) orbit... as we speak it is around 0.05 to 0.06 AU from Earth - so you can see it isn't too far out of the plane field. Thus the comet's orbit is between about as close as you can get - or a bit too close- between Earth and Jupiter. Talk about being between a rock and a hard place...if Comets are Hairy Stars SW-3 is certainly getting its hair pulled...hope that puts it in better perspective and that one thing doesn't bother you as much now! I don't think the comet needed to be especially weak, or any specific fault line, or any of that reasoning. It is just in-play at the moment. Another day in the life of the Solar System. And you're lucky to be in the Stadium with front row seats. I just looked for component B which is at closest approach to the Earth. The Full Moon 90 degrees away totally washes it out. Saludos, Doug PS According to Japanese calculations it came apart in 1995. PPS This comet has been know for flare ups in prior apparitions, so again, nothing suprising, we're just in the right place at the right time and the camel's back is broken. Sterling W. wrote: What bothers me about Comet 73P is this: It can't be a new comet (even though we discovered it in 1930). The orbit is too stable for the comet to have recently been thrown in there. It's been around for centuries, probably millennia, in this same orbit. Yet, it has unraveled so quickly and easily. Once it started to come apart, sometime between 1990 and 1995, __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] BREAK! For the love of meteorites, STOP
Hello List, Sorry I just asked a short question and didn't think it would be such a stream of answers and comments... At least I learned that some samples are being studied and that's a good point. In the meantime, as we usually do when we have a REAL meteorite, we wait for the results before advertising it ; but I agree that he does not really advertise the rock but himeself. I think that we can close the topic now, can't we? Cheers, Fred - Original Message - From: Pete Pete [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: meteorite-list@meteoritecentral.com Sent: Sunday, May 14, 2006 6:06 AM Subject: RE: [meteorite-list] BREAK! For the love of meteorites, STOP Hello, List, There has been over thirty posts in this thread with barely an interruption. Nothing else to talk about? While curious about the composition of this rock only from a geology perspective, I too would rather read a lengthy discussion about something more relative to the list. I'm hoping Sterling K. Webb will give us his analytical dissection of the disintegration of Comet 73P, in his usual interestingly descriptive way! From the top, Sterling! And some thoughts about its predicted meteor shower in 2022, if you will.(any speculation as to survivors to the surface then?) http://www.space.com/scienceastronomy/060510_comet_spitzer.html http://www.space.com/scienceastronomy/060510_comet_spitzer.html Cheers, Pete From: [EMAIL PROTECTED] To: Pete Pete [EMAIL PROTECTED] CC: meteorite-list@meteoritecentral.com Subject: RE: [meteorite-list] For the love of meteorites, STOP Date: Sun, 14 May 2006 02:42:43 + The man isn't interested in selling it. It's his ploy. A way to attract attention. No amount of effort matters to him. He won't sell his lucky charm now or in the future. Expect to see his ad for years to come unless ebay stops him. Bill -- Original message -- From: Pete Pete [EMAIL PROTECTED] Hi, Mike, I guess you didn't read any of the early posts in this thread - it CAN be solved! Gary has some samples for the lab, and there will soon be a legitimate, definitive end to it. No one thinks it's from Mars, or Voltar, but it seems to me that if you have a scientific interest in meteorites and their composition, then an interest in terrestrial geology would be quite natural. That rock does have some interesting properties. Like Gary said - if it is found to be a mineral worth a couple of bucks, the guy can sell it honestly for what it really is. Cheers, Pete From: Michael Farmer [EMAIL PROTECTED] To: 'metlist' meteorite-list@meteoritecentral.com Subject: [meteorite-list] For the love of meteorites, STOP Date: Sat, 13 May 2006 18:54:50 -0700 My god people, I was in Dallas and barely 3 hours later by the time I flew home, there are more than 30 new messages regarding the stupid fake mars rock on ebay. We have been dealing with this fruitcake for years, so please, STOP FEEDING THE FRENZY and forget this nutjob. I for one, am sick of reading about something that can not be solved and we really have no right to argue about. Michael Farmer __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Comet 73P SW-3 Part II (was Visions, Morals, Religion, eBay, etc.)
Here's what I mean, courtesy of Don Yeomans'/JPL site, http://ssd.jpl.nasa.gov/sbdb.cgi?ID=c00073_b;orb=1;cov=0#orb The above ought to be a link to C/73P SW-3 (B component) picture of the current comet's orbit. While it is not too accurate to extrapolate backwards on this fragment, they are similar and you get the idea if you go to November 2, 1965, appropriately sizing the orbit graphic with the zoom, and you can see ho little tilt the orbit has, too. Put today's date in, too, for fun:) I just went outside again and did manage to see the B fragment now at its closest approach to us in Cygnus the Swan under the Full Moon with a 2 inch refractor, typical low power terrestrial sighting scope at 20X. The comet fragment is booking dipping downward thats for sure - moving, and I'm guessing, nearly a full Moon diameter every three hours against the star background. That is big time, really impressive, but the show is so meek as the comet was so hard to see under these conditions I am still seeing cross-eyed and stiff necked. I suspect if this fragmented B-lot were to slam into Earth right now it wouldn't even be much of an earth shattering event except in the meteorite and astrophotography community. Saludos, Doug PS the B fragment is approximately as bright as the C fragment (officially barely naked eye, though I think that exaggeration applies to Cyclops) which supposedly is the largest while B fragments are #2 mass, but really who knows, from the looks of it, B is probably just a few wet piles of gravel at this point... __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: AW: AW: [meteorite-list] fake Mars back on ebay charset=iso-8859-1
Ministry my ass. Geese. This man has a church and ministry in place. He is not a dangerous J Jones or Hale Bopp sleeper... he is someone who believes he has had a vision from God - period. We all know that means he will not release his beliefs lightly. But he is curious as to what proper labs will tell him. In the meantime he is well aware of how much his auction has been seen and is glad it is getting a message out. But that is all his personal belief. Am I taken by this man? Yes. He is well spoken and well considered in his hometown. Do I believe him? Not for a minute. So, have I been 'taken in' by this man? Not at all. I am focused on identifying the specimen and helping him find a buyer for a proper price. I keep telling him the odds of it being a meteorite of any kind are slim to none. As for his giving a hoot about meteorites, he is now fascinated by them. I gave him a small unclassified NWA individual chondrite and he carries it with him all the time. Wants to know all about it and other meteorites. So, not only is it possible to identify a truly unique specimen here, but there is room for education as well. This is about as far from being a waste of time as I can think of. Gary On 14 May 2006 at 1:37, [EMAIL PROTECTED] wrote: What is all this? Why is everyone wasting their breath? The man must be pretty slick. Gary sure seems to be quite taken with him. Like any charleton he'll use whatever means he has to achieve his ends. The sickest part is that it's in the name of religion. I'm sure he doesn't give a hoot about meteorites. He should be ashamed of himself. Promoting God as truth by setting up an ebay sideshow based on a pack of bizzare lies. I don't believe for a second that he isn't fully aware of his actions. I wonder how many people he's taken in as a result of his ebay sale. I imagine a lot, or he wouldn't keep running this hogwash. That ad of his is a flytrap for poor deluded minds of which there is no shortage unfortunately. Ebay is a place to trade in merchandise not souls. Ebay should strip him of his pulpit. Would they have allowed tickets for the Hale-Bopp spaceship to be sold there? Jim Jones vacation packages. Ministry my ass. Geese. Bill -- Original message -- From: Gary K. Foote [EMAIL PROTECTED] and the sky would be blue and the roses and the hematite of New Hampshire would blossom redder than eve Very entertaining Martin. But regarding dreams - a man without dreams is a hollow man. I seek the truth in this thing. I have not made conclusions ahead of evidence. But I do believe there is SOME value to that specimen that is due the man who found it. Let him think its from Mars. If UNH ends up with a nice display piece for their geology department - for a fair price to the finder, where is the harm? Gary Sir 34:1-7 The hopes of a man void of understanding are vain and false: and dreams lift up fools. Whoso regardeth dreams is like him that catcheth at a shadow, and followeth after the wind. The vision of dreams is the resemblance of one thing to another, even as the likeness of a face to a face. Of an unclean thing what can be cleansed? and from that thing which is false what truth can come? Divinations, and soothsayings, and dreams, are vain: and the heart fancieth, as a woman's heart in travail. If they be not sent from the most High in thy visitation, set not thy heart upon them. For dreams have deceived many, and they have failed that put their trust in them. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] BREAK! For the love of meteorites, STOP
'Nuff said. I'll only report lab results, not progress in the future. Gary On 14 May 2006 at 12:17, Meteoriteshow wrote: I think that we can close the topic now, can't we? __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] fake Mars back on ebay
Howard - where is your sense of curiosity? All tied up in meteorics? Gary On 13 May 2006 at 19:12, Howard Steffic wrote: OK,: FAKE MARS ROCK = waste of time From: Gary K. Foote [EMAIL PROTECTED] Reply-To: [EMAIL PROTECTED] To: Howard Steffic [EMAIL PROTECTED] CC: Meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] fake Mars back on ebay Date: Sat, 13 May 2006 19:26:20 -0400 I'm focused on the specimen, not the man. Gary On 13 May 2006 at 17:11, Howard Steffic wrote: CRACKPOT = Waste of time. From: Pete Pete [EMAIL PROTECTED] To: [EMAIL PROTECTED], Meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] fake Mars back on ebay Date: Sat, 13 May 2006 17:27:59 -0400 Science is the search for truth. I don't think Gary is wasting any time, at all! Cheers, Pete From: Howard Steffic [EMAIL PROTECTED] To: Meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] fake Mars back on ebay Date: Sat, 13 May 2006 15:00:35 -0600 I am going to go out on a limb and make two predictions: 1) It is terrestrial. I will bet my first born on it. 2) The guy is a nut case and Jesus Christ himself could tell him it is not from Mars and the Ebay Auctions would continue. I wouldn't cross the street to give the guy the time of day. Don't waste any more of your time Gary. - Original Message - From: Gary K. Foote [EMAIL PROTECTED] To: Darren Garrison [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: Meteorite-list@meteoritecentral.com Sent: Saturday, May 13, 2006 2:20 PM Subject: Re: Re: [meteorite-list] fake Mars back on ebay Hi Darren, He is different. I have met him and have seen this supposed meteorite up close. I have some crumbs and small chips but have two 6 X 1/2 slices coming to me soon. I have also arranged for two more slices to go to reputable geologists to find out just what it is. Whatever it is, it should be identified and placed in the proper museum for showing. It is unbelievable in person. I suspect Magnetite schist or perhaps upthrust continental shelf shaped by magamtic-granite and magnetite replacement, but that is for the experts to answer. Whatever it is it has a value inherent by its magnitude and unusual shape. If it can be explained and displayed to the public I hope he can make some $$$ for his ministry along the way. He is convinced his vision from God is the fact of the matter, and I have explained to him why that is nigh impossible, but he has his convictions. Truth be told, he didn't preach or try to convert and is eager to identify what he has. Still, he will, in my opinion, retain his personal beliefs about its origin. Gary On 13 May 2006 at 14:18, Darren Garrison wrote: On Sat, 13 May 2006 12:06:19 -0400, you wrote: Easy - the man tells the truth. His verification is by personal vision and he makes that perfectly clear. Therefore there is no fraud. Right. He's not a conman-- he's just a freaking nutjob. __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list _ On the road to retirement? Check out MSN Life Events for advice on how to get there! http://lifeevents.msn.com/category.aspx?cid=Retirement __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list _ FREE pop-up blocking with the new MSN Toolbar get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/ __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list _ Dont just search. Find. Check out the new MSN Search! http://search.msn.click-url.com/go/onm00200636ave/direct/01/ __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] the never ending thread,a vision of a mars rock
Hi list and good morning.I am like most on this list,LETS END THIS THREAD .and move on to REAL meteorites.I do though give Gary total credit for what he did.He went to the owner to tell him what the rock PROBABLY is and what we all know what it is not.Everone is in titled to their own opinion.If that was a real mars rock,the minister could give it all away to all his flock and make them never have to work a day in lives again.But for some of the our distinguished meteorite panel to knock the guy who has nothing to do with this list is not right.Everyone has put in their 2 cents worth and it has all been noted by the meteorite community.I am putting in my money so I think it should end and lets get back to real rocks.You do have to admit,it does really look WEIRD.Again cudos to Gary for taking time out of his schedule to finally and hopefully put an end to this farce and we all can get to what is really meaningful to us all,METEORITES.In my paltry collection I do not even own a mars piece.But when the time is right you never know.But for now thanks again Gary and thanks for letting us know what we all wanted to know about that big rock. Steve Arnold,Chicago,USA!! Steve R.Arnold, Chicago, IL, 60120 Illinois Meteorites,Ltd! website url http://stormbringer60120.tripod.com __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] fake Mars back on ebay
Having a crackpot's FAKE mars rock as the first listing in the ebay meteorite category can NOT be doing this hobby any good. Someone needs to steal his fake Mars rock and dump it in a lake so he can move on to his next scam. Maybe the face of Jesus on his toast? Anything but this thorn in the Meteorite Hobby's side. Howard From: Gary K. Foote [EMAIL PROTECTED] Reply-To: [EMAIL PROTECTED] To: Howard Steffic [EMAIL PROTECTED] CC: Meteorite-list@meteoritecentral.com Subject: Re: [meteorite-list] fake Mars back on ebay Date: Sun, 14 May 2006 07:48:30 -0400 Howard - where is your sense of curiosity? All tied up in meteorics? Gary On 13 May 2006 at 19:12, Howard Steffic wrote: OK,: FAKE MARS ROCK = waste of time _ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/ __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] fake Mars back on ebay
On Sun, 14 May 2006 07:48:31 -0400, you wrote: This man has a church and ministry in place. He is not a dangerous J Jones or Hale Bopp sleeper... he is someone who believes he has had a vision from God - period. We all know that means he will not release his beliefs lightly. Which is all fine until his NEXT vision from God tells him to do something less harmless. People who believe that God is directly telling them what to do and that the messages from God are above all man's laws are dangerous people, period. For an example, google the words miserable failure and click on the first link. (And I'll drop this off topic thread now). __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] Email VIRUS alert
Hi, all, I just received a dozen emails with *infected* attachments from: azroumeteorites [EMAIL PROTECTED] They were all deleted by my anti-virus program automatically, but in case yours doesn't grab it, don't open the attachments. Cheers, Pete __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] Email VIRUS alert
Hi List! I have received also some e-mails from [EMAIL PROTECTED]! I have looked on the attached files and... no problems! Ingo --- Ursprüngliche Nachricht --- Von: Pete Pete [EMAIL PROTECTED] An: meteorite-list@meteoritecentral.com Betreff: [meteorite-list] Email VIRUS alert Datum: Sun, 14 May 2006 12:21:55 -0400 Hi, all, I just received a dozen emails with *infected* attachments from: azroumeteorites [EMAIL PROTECTED] They were all deleted by my anti-virus program automatically, but in case yours doesn't grab it, don't open the attachments. Cheers, Pete __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list -- GMX Produkte empfehlen und ganz einfach Geld verdienen! Satte Provisionen für GMX Partner: http://www.gmx.net/de/go/partner __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
[meteorite-list] World's Meteorite Shows
Dear List, We have had a request to create a page listing dates and info on all the World's Meteorite Shows. We would appreciate links to any lists and pages that you know of. Please reply off the list to [EMAIL PROTECTED] We'll make the page available from both The Meteorite Exchange and Meteorite-Times. Thank you! Paul __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P
Doug, List, I abase my unworthy self, to be Japanese about it. I Googled for orbit data, and didn't Google deep enough. It's a virtual Jupiter-Earth Shuttle, it seems. I re-traced my steps from my browser history and discovered a wrong click pulled the data from a different object, a perfect three-in-the-morning error. At 3 ayem, I should be asleep or squinting at comet fragments instead of posting... Anyway, I take it all back. So close, but so dim. The rapid breakup which formerly brightened it prematurely is extinguishing it prematurely now. Why can't we have a nice fresh long-period comet with an absolute magnitude of -1 and a close approach in the midnight zenith position for the northern hemisphere at the time of a new moon? Don't want much, do I? Sterling - - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED]; meteorite-list@meteoritecentral.com Sent: Sunday, May 14, 2006 4:46 AM Subject: Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P Sterling, Stable Orbit for Millennia for 73P? Not a snowball's chance in errr,, the hot box (ref.: baseball play, a.k.a. a rundown in the pickle)! The similar basic mechanism that delivers meteorites to us has made this a very Hot comet in its recent passes. It has several encounters with Jupiter over the last 100 years which have probably significantly tagged it out and knocked its orbit silly, not to mention Earth, too, which hits it when it is nice and soft. In 1965 it passed just a 0.25 AU from Jupiter and that is a pretty deadly thing - with accelerations, and that is just one of the large examples. This comet pile currently has an aphelion of 5.2- AU an itsy bit inside of Jupiter's (5.2+ AU) orbit, and a perihelion of 0.94 AU just inside Earth's (1.0 AU) orbit... as we speak it is around 0.05 to 0.06 AU from Earth - so you can see it isn't too far out of the plane field. Thus the comet's orbit is between about as close as you can get - or a bit too close- between Earth and Jupiter. Talk about being between a rock and a hard place...if Comets are Hairy Stars SW-3 is certainly getting its hair pulled...hope that puts it in better perspective and that one thing doesn't bother you as much now! I don't think the comet needed to be especially weak, or any specific fault line, or any of that reasoning. It is just in-play at the moment. Another day in the life of the Solar System. And you're lucky to be in the Stadium with front row seats. I just looked for component B which is at closest approach to the Earth. The Full Moon 90 degrees away totally washes it out. Saludos, Doug PS According to Japanese calculations it came apart in 1995. PPS This comet has been know for flare ups in prior apparitions, so again, nothing suprising, we're just in the right place at the right time and the camel's back is broken. Sterling W. wrote: What bothers me about Comet 73P is this: It can't be a new comet (even though we discovered it in 1930). The orbit is too stable for the comet to have recently been thrown in there. It's been around for centuries, probably millennia, in this same orbit. Yet, it has unraveled so quickly and easily. Once it started to come apart, sometime between 1990 and 1995, __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P
Hi, Sterling and Doug, Thanks for your valued input. Regarding the 2022 shower, I was wondering how different that spectacle will be considering it won't be the normal dust-to-pea-sized coma debris, but more likely some considerable chunks included, due to the current and nicely timed disintegration. Armegaddon!? What side of the planet should we be on then? (-Rhetorical ;]) At this rate of break-up, is it possible that there won't be a comet left for a return trip from around the sun? Cheers, Pete From: Sterling K. Webb [EMAIL PROTECTED] To: Meteorite List meteorite-list@meteoritecentral.com,[EMAIL PROTECTED],Pete Pete [EMAIL PROTECTED] Subject: Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P Date: Sun, 14 May 2006 03:08:50 -0500 Hi, Pete, Your message came just in time. I was typing a snide remark about the Hematitic Lump From Mars. (Somebody forward to this guy Göran Axelsson's picture of the identical tone rock in Sweden at a church, and explain to the guy that he got God's message all mixed up -- he's supposed to use his rock as the bell for his church, not sell it on eBay!) What bothers me about Comet 73P is this: It can't be a new comet (even though we discovered it in 1930). The orbit is too stable for the comet to have recently been thrown in there. It's been around for centuries, probably millennia, in this same orbit. Yet, it has unraveled so quickly and easily. Once it started to come apart, sometime between 1990 and 1995, it has split, re-split, fractured. If you go back and read the earliest studies this pass, the authors clearly expected that whatever splits had occured at the time they wrote to be the extent of splitting when they passed the Earth. Three fragments would be visible, they said. Whoops, make that six fragments. Uh-oh, make that 9, 12, 30. I'm not making fun of the researchers, but our experience of split comets is that this disintegration takes a while. 73P has just gone to hell overnight. It must be very, very weak, they say. OK, BUT... If it's that weak, what has been holding it together for the last 75 years (and for centuries before that)? Thermal stress is pegged as the likely culprit for the breakup, but it's been exposed to the Sun for a long time. How could it have survived so long if it was this fragile? My guess answer is that the fragile material was probably adhered to something that wasn't fragile, like a small rocky core. This small dark object would have been completely shielded from the Sun by the weak porous fluffy ices that surrounded it and made up the outer body of the comet. But once a good chunk of those ices cracks off from a tiny impact or from thermal stress, it exposes a portion of the dark rock core to sunlight; the rock warms and more fragments of icy fluff soon come loose. They're too small to survive and rapidly break up in a cascade of fragments, as we've seen. A bare dark rock object is left behind in an orbit similar to the other fragments, but it's too distant to be detected... yet. I'm looking forward to the discovery of a small Earth-crossing asteroid in 2011, 2016, 2022 with an orbit very like Comet 73P! It would not be a big one. The pre-breakup 73P nucleus was only 1000-1200 feet in diameter; a core is unlikely to be more than a few hundred feet across (30 to 80 meters), I hope, instead of 400 meters. Despite the fact that meteor showers are so showy, no fall has ever been associated with them. Only one fall was ever witnessed during a meteor shower and recovered, and it was an iron, a complete coincidence. The biggest fragments in a meteor shower are smaller than a pea, moving very fast, and in for a short bright ride, then Pffft! Small junk never makes it through the atmosphere. Predicting future meteor shower orbits is the most thankless job in number crunching. Some people like it for that very reason. Every little piece of cometary material is capable of puffing little jets of gas; every little jet is a thrust; every thrust alters the precise orbit somewhat; the thrusts go on for months with progressive orbital changes, like ion engines. Some jets are on rotating bodies, so the thrusts are like pinwheel jets, pushing this way then that way. To quote Charlton Heston in Planet of the Apes, It's a madhouse! A madhouse! How spectacular a close comet approach is depends not only on how close but on how big. The close approach of a really big fresh long-period comet is probably the most spectacular thing that is visible in the sky, apart from a Type II supernova 700 light years away. We haven't had one really spectacular one for over a century and a half, but the century before that was blessed with some giant apparitions, as they are called, in 1729 and 1744, and the 19th century had flashier big meteor showers than the 20th. Maybe we're due for one. As for people who worry about close approaches, here's a table of the 20 closest approaches of
Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P
Pete Pete, Not to slight all the experts on the met-list, try http://www.meteorobs.org. They are hardcore specialists. Bill -- Original message -- From: Pete Pete [EMAIL PROTECTED] Hi, Sterling and Doug, Thanks for your valued input. Regarding the 2022 shower, I was wondering how different that spectacle will be considering it won't be the normal dust-to-pea-sized coma debris, but more likely some considerable chunks included, due to the current and nicely timed disintegration. Armegaddon!? What side of the planet should we be on then? (-Rhetorical ;]) At this rate of break-up, is it possible that there won't be a comet left for a return trip from around the sun? Cheers, Pete From: Sterling K. Webb [EMAIL PROTECTED] To: Meteorite List meteorite-list@meteoritecentral.com,[EMAIL PROTECTED],Pete Pete [EMAIL PROTECTED] Subject: Re: [meteorite-list] BREAK! For the love of meteorites, STOP -- COMET 73/P Date: Sun, 14 May 2006 03:08:50 -0500 Hi, Pete, Your message came just in time. I was typing a snide remark about the Hematitic Lump From Mars. (Somebody forward to this guy Göran Axelsson's picture of the identical tone rock in Sweden at a church, and explain to the guy that he got God's message all mixed up -- he's supposed to use his rock as the bell for his church, not sell it on eBay!) What bothers me about Comet 73P is this: It can't be a new comet (even though we discovered it in 1930). The orbit is too stable for the comet to have recently been thrown in there. It's been around for centuries, probably millennia, in this same orbit. Yet, it has unraveled so quickly and easily. Once it started to come apart, sometime between 1990 and 1995, it has split, re-split, fractured. If you go back and read the earliest studies this pass, the authors clearly expected that whatever splits had occured at the time they wrote to be the extent of splitting when they passed the Earth. Three fragments would be visible, they said. Whoops, make that six fragments. Uh-oh, make that 9, 12, 30. I'm not making fun of the researchers, but our experience of split comets is that this disintegration takes a while. 73P has just gone to hell overnight. It must be very, very weak, they say. OK, BUT... If it's that weak, what has been holding it together for the last 75 years (and for centuries before that)? Thermal stress is pegged as the likely culprit for the breakup, but it's been exposed to the Sun for a long time. How could it have survived so long if it was this fragile? My guess answer is that the fragile material was probably adhered to something that wasn't fragile, like a small rocky core. This small dark object would have been completely shielded from the Sun by the weak porous fluffy ices that surrounded it and made up the outer body of the comet. But once a good chunk of those ices cracks off from a tiny impact or from thermal stress, it exposes a portion of the dark rock core to sunlight; the rock warms and more fragments of icy fluff soon come loose. They're too small to survive and rapidly break up in a cascade of fragments, as we've seen. A bare dark rock object is left behind in an orbit similar to the other fragments, but it's too distant to be detected... yet. I'm looking forward to the discovery of a small Earth-crossing asteroid in 2011, 2016, 2022 with an orbit very like Comet 73P! It would not be a big one. The pre-breakup 73P nucleus was only 1000-1200 feet in diameter; a core is unlikely to be more than a few hundred feet across (30 to 80 meters), I hope, instead of 400 meters. Despite the fact that meteor showers are so showy, no fall has ever been associated with them. Only one fall was ever witnessed during a meteor shower and recovered, and it was an iron, a complete coincidence. The biggest fragments in a meteor shower are smaller than a pea, moving very fast, and in for a short bright ride, then Pffft! Small junk never makes it through the atmosphere. Predicting future meteor shower orbits is the most thankless job in number crunching. Some people like it for that very reason. Every little piece of cometary material is capable of puffing little jets of gas; every little jet is a thrust; every thrust alters the precise orbit somewhat; the thrusts go on for months with progressive orbital changes, like ion engines. Some jets are on rotating bodies, so the thrusts are like pinwheel jets, pushing this way then that way. To quote Charlton Heston in Planet of the Apes, It's a madhouse! A madhouse! How spectacular a close comet approach is depends not only on how close but on how big. The close approach of a really big fresh long-period comet is probably the most spectacular thing that is visible in the sky, apart from a Type II supernova 700 light years away. We haven't had one really spectacular one
[meteorite-list] Tsunami Risk of Asteroid Strikes Revealed
http://www.newscientistspace.com/article/dn9160-tsunami-risk-of-asteroid-strikes-revealed.html Tsunami risk of asteroid strikes revealed Jeff Hecht New Scientist 12 May 2006 Tsunamis triggered by asteroid impacts cause a disaster similar to the 2004 Asian tsunami once every 6000 years on average, according to the first detailed analysis of their effects. Researchers have assumed that tsunamis would make ocean impacts more deadly than those on land. But Steve Chesley at the Jet Propulsion Laboratory in Pasadena, and Steve Ward at the University of California at Santa Cruz, both in the US, are the first to quantify the risks. The pair first calculated the chance of various size asteroids reaching the Earth's surface, and then modelled the tsunamis that would result for asteroids that hit the oceans. For example, the model shows that waves radiating from the impact of a 300-metre-wide asteroid would carry 300 times more energy than the 2004 Asian tsunami. You can view movies of impact simulations in the North Atlantic http://es.ucsc.edu/~ward/1950-DA(5).mov, South Atlantic http://es.ucsc.edu/~ward/eltanin_small.mov, Gulf of Mexico http://es.ucsc.edu/~ward/2004MN4(b).mov and Pacific http://es.ucsc.edu/~ward/2004MN4(a).mov (all in .mov format). Fifty million people To accurately assess the overall impact-tsunami risks, the analysis included the full range of asteroid sizes, including the smallest asteroids capable of penetrating the Earth's atmosphere. These are between 60 and 100 metres, depending on their composition. The most common asteroids, between 100 m and 400 m, would yield tsunami waves up to 10 m when they arrived at the coast. A total of about 50 million coastal residents are vulnerable to such waves, though no single impact would affect them all. The researchers predict a tsunami-generating impact should occur about once every 6000 years, and would on average affect over one million people and cause $110 billion in property damage. The study also showed that asteroid impacts in the 300-metre class might be similar to the huge tsunamis thrown up when massive chunks of rock break from the sides of volcanoes and fall into the ocean. These events are also thought to occur roughly once every 6000 years. The analysis confirms suspicions that tsunamis are the biggest risk posed by asteroid impacts. The risks from climate effects of big impacts - through dust and smoke that blocks out the Sun - are about two-thirds that of tsunamis, while those of land impacts are about one-third of the tsunami risk. Hurricane aspects There still are a lot of uncertainties, Chesley cautions. The solar system's population of 100 m to 400 m asteroids is poorly known, as are coastal population distributions. A big question is how the waves would behave when they reach the shore; successive wave peaks are much closer together in asteroid tsunamis than in earthquake tsunamis (see a simulation of an asteroid hitting the water, here http://es.ucsc.edu/~ward/splash_250m.mov). But the ultimate uncertainty is when and where an asteroid might hit. Asteroids sprinkle down pretty much at random, says Ward, They don't pick out California or Florida. And, like hurricanes, location is the key. Hurricane Katrina became America's worst natural disaster in living memory not because it was the biggest storm, but because it made a direct hit on vulnerable New Orleans. But while hurricanes are difficult to predict, they do follow the same general paths. Asteroids come out of the blue - literally. Journal reference: Natural Hazards (vol 38 p 355) __ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
