Showing posts with label 2008 meteor. Show all posts
Showing posts with label 2008 meteor. Show all posts

27 March 2009

2008 TC3, Almahata Sitta meteorite came from F-class asteroid 26MAR09

http://www.sciam.com/article.cfm?id=asteroid-meteorite-sudan-fireball

Rock Science: First Meteorites Recovered on Earth from an Asteroid Tracked in Space Fragments in the Sudanese desert make up an "asteroid trifecta":
discovery, prediction and recovery By John Matson Scientific American March 25, 2009

Last October, asteroid monitors at the Catalina Sky Survey at the University of Arizona in Tucson picked up a small object on an immediate collision course with Earth. The asteroid was too small to present a real threat - just a few meters across, it stood little chance of penetrating the atmosphere intact. Indeed, it exploded in astratospheric fireball over northern Sudan less than 24 hours later - anevent witnessed by people on the ground as well as the pilots of a KLM airliner- conforming well to astronomer's predictions for its trajectory. But the asteroid, dubbed 2008 TC3, was nonetheless a momentous discovery: Among the countless small objects that strike Earth's atmosphere every year, none had ever been detected and tracked before it impacted. Now the Sudan bolide has yielded yet another first:

Researchers report in Nature today
<http://www.nature.com/nature/journal/v458/n7237/full/nature07920.html>that they have recovered 47 meteorites from the object in the Nubian Desert. And lead author Peter Jenniskens, a meteor astronomer at the SETI Institute in Mountain View, Calif., says that another search completed earlier this month, after the paper was submitted, has upped the meteorite count to about 280.
Astronomer Donald Yeomans, manager of NASA's Near-Earth Object Programoffice <http://neo.jpl.nasa.gov/> at the Jet Propulsion Laboratory inPasadena, Calif., calls 2008 TC3 "a perfect asteroid trifecta,"referring to "pre-impact discovery, successful impact prediction, and successful sample return." (Yeomans did not contribute to the recovery research, but his office played a leading role in tracking the asteroid's entry <http://www.cfa.harvard.edu/mpec/K08/K08T50.html>.)

The find allows astronomers to connect the chemical composition of the meteorite to its orbit and reflectance in the sky during tracking. "The holy grail of asteroid science is to uniquely link a specific meteorite and its detailed composition to a specific asteroid type," Yeomans says."And that has now been done without an expensive sample-return mission. "This object, which the study's authors call Almahata Sitta (Arabic for Station Six, a train station in the desert where eyewitnesses saw the fireball and that served as the researchers' base camp), appears to belong to a rare class of bodies called F-class asteroids, which constitute just 1.3 percent of all asteroids. Chemically speaking, Almahata Sitta is a meteorite whose specific composition is unique among meteorite collections. It is a fragile, porous ureilite (a relatively rare kind of olivine- and pyroxene-bearing meteorite)containing graphite and nanodiamonds, among other materials. Its fragility, Jenniskens says, helps explain why it broke apart so high in the atmosphere. With the benefit of the object's rarity as an F-class body and its orbit, tracked backward through time, the researchers established a possible link to a larger F-class asteroid, the 1.6-mile-(2.6-kilometer-) diameter 1998 KU2, which may have originated from the same parent body as Almahata Sitta."The orbit of the asteroid, by just tracking it for 20 hours, is 10,000times better than anything you can get from just observing a fireball Jenniskens says. "What's neat about this is that the big asteroid allows you to extend back in time the evolutionary history." He notes that scientists might be able to pinpoint the specific region of the asteroid belt that 2008 TC3 came from with more F-class asteroids from the same parent body. Even the brief amount of time 2008 TC3 was tracked provided an excellent lead on where to look- and the desert surface provided an ideal surface for turning up the dark fragments. "The entry trajectory was very precisely known," Jenniskens says. The first samples were found in early December by a 45-person search team from the University of Khartoum. (Three scientists from that university and one from the University of Juba in Sudan are among the co-authors of the study.) "We had many eyes and hands," Jenniskens says, trying "to find these."

13 March 2009

Upcoming International Meteor Conference-Croatia Sep 24-27, 2009

International Meteor Conference
Porec, Croatia, September 24-27, 2009
=====================================
This year, the International Meteor Conference (IMC) will take place from September 24 to 27 in Croatia, at a beautiful location on the coast of the Adriatic Sea, located on the Istrian Peninsula. The IMC is one of the highlights of the meteoric year and a unique opportunity to meet like-minded people from all over the world and to exchange experiences. In particular, you have the opportunity to present your own results or those of your observing group by giving a presentation. In that case, you will see the paper of your presentation published in the proceedings that will be compiled after the event.
Participation in the 2009 IMC costs 160 euro for IMO (International Meteor Organization) members. This sum includes full board in the conference hotel, all sessions, the conference excursion, a 2009 IMC T-shirt, and the conference proceedings. Early registrants get a reduction of 10 euro. You can register by filling out the electronic registration form and paying the registration fee, or making a prepayment of at least 75 euro.
Registration and Conference information: http://www.imo.net/imc2009

06 March 2009

Parry Sound, Ontario, Canada Meteor of March 5, 2008 One Year Ago


Photo by Univ. of Western Ontario, CAO-RASC (c)2008
Parry Sound, Ontario, Canada Meteor--March 5, 2008 at 10:59 p.m. EST

Anyone have any updates concerning meteorite finds from this meteor? Please comment on this post if you have any information. Thank you.

Western astronomers on hunt for meteor
By Communications Staff Friday, March 7, 2008
Astronomers from The University of Western Ontario have captured rare video of a meteor falling to Earth, and are hoping to enlist the help of local residents in recovering one or more possible meteorites that may have crashed in the Parry Sound area.

Map (Zoom)
Map (Full Version 1)
Map (Full Version 2)
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Video File (.avi)
Video File (.mov)

The Physics and Astronomy Department at Western has a network of all-sky cameras in Southern Ontario that scan the sky monitoring for meteors. Associate Professor Peter Brown, who specializes in the study of meteors and meteorites, says that Wednesday evening (March 5) at 10:59 p.m. EST these cameras captured video of a large fireball and the department has also received a number of calls and emails from people who actually saw the light. Brown along with Wayne Edwards, a post doctorate student, are now working to get the word out among interested people who may be willing to see if they can spot any fallen meteorites. “Most meteoroids burn up by the time they hit an altitude of 60 or 70 kilometres from Earth," says Edwards. “We tracked this one to an altitude of about 24 kilometres so we are pretty sure there are at least one, and possibly many meteorites, that made it to the ground." Edwards says the lab can narrow the ground location where the meteorite would have fallen, to about 12 square kilometres and have created a map that may assist in locating the meteorite. The rock, or rocks, would probably weigh a kilogram or slightly more. “We would love to find a recovered meteorite on this one, because we have the video and we have the data and by putting that together with the meteorite, there is a lot to be learned." Wayne Edwards is available for interviews and/or to report finds at 519-850-2385. He can also be reached via email at wedwards@uwo.ca If you would like to receive a 14-mb video file of the meteor in avi format, maps or an image, please reply to this email address.

Reply Comment by Mark Langenfeld:
While I have heard nothing further, the linked maps suggest whatever survived may have splashed into Georgian Bay.

Reply Comment by Patrick Herrmann:
Nothing had been recovered from that fall. The stones fell too far out in Georgian Bay, and the ice was too thin to go by snowmobile. Point-au-Baril is what they ended up calling the potential strewn field.I was trying to get a helicopter lined up to go and look for some stones, but then, about a week or so after the fireball, there was another snowstorm, and that was it.