Re: NASA Teleconference about Sudan Meteorite
I just logged in at the end. Can anyone fill me in on what I missed?
Thanks
I just logged in at the end. Can anyone fill me in on what I missed?
Thanks
- Status
Re: NASA Teleconference about Sudan Meteorite
Hi Wayne, could you email the image to me & I'll try & link it to an outside host on your behalf.
I've emailed you too, regarding a possible recording of the NASA Teleconference.
Missed it due to me still being at work. Damn. Would have loved to have listened to it.
Andrew Brown.
MeteorWayne":99roaw0n said:
Hi Wayne, could you email the image to me & I'll try & link it to an outside host on your behalf.
I've emailed you too, regarding a possible recording of the NASA Teleconference.
Missed it due to me still being at work. Damn. Would have loved to have listened to it.
Andrew Brown.
Re: NASA Teleconference about Sudan Meteorite
Thanks to the article on the front page of this site, NOW i realize what is so special about this meteorite. This is the first one we have recovered after tracking it BEFORE it hit the earth's atmosphere. So we have an idea what its orbit was, it's size before impact, its light signature, etc.
Thanks to the article on the front page of this site, NOW i realize what is so special about this meteorite. This is the first one we have recovered after tracking it BEFORE it hit the earth's atmosphere. So we have an idea what its orbit was, it's size before impact, its light signature, etc.
Re: NASA Teleconference about Sudan Meteorite
Picture of the meteorite, from New Scientist
Article is interesting: http://www.newscientist.com/article/dn16843-meteorite-hunters-strike-gold-in-sudan.html
The recovered bits of asteroid 2008 TC3, like the meteorite shown here, typically have a dark, scruffy texture. They are eurelites, a type of meteroite that is only partially melted. By comparing the spectrum of the meteorites with observations of 2008 TC3 while it was still approaching Earth, astronomers can now link eurelites with dark, F-class asteroids. This is the first time rocks that have fallen to Earth have been definitively matched up with a particular class of parent asteroids (Image: P Jenniskens/SETI Institute/NASA)
Picture of the meteorite, from New Scientist
Article is interesting: http://www.newscientist.com/article/dn16843-meteorite-hunters-strike-gold-in-sudan.html
The recovered bits of asteroid 2008 TC3, like the meteorite shown here, typically have a dark, scruffy texture. They are eurelites, a type of meteroite that is only partially melted. By comparing the spectrum of the meteorites with observations of 2008 TC3 while it was still approaching Earth, astronomers can now link eurelites with dark, F-class asteroids. This is the first time rocks that have fallen to Earth have been definitively matched up with a particular class of parent asteroids (Image: P Jenniskens/SETI Institute/NASA)
Re: NASA Teleconference about Sudan Meteorite
If anyone want to spend the time, the teleconference is suppose to be available at 1-888-403-4660 until May 1. I will be listening a bit later this afternoon.
If anyone want to spend the time, the teleconference is suppose to be available at 1-888-403-4660 until May 1. I will be listening a bit later this afternoon.
Re: NASA Teleconference about Sudan Meteorite
It should be interesting to see what this conference reveals.
It should be interesting to see what this conference reveals.
Re: NASA Teleconference about Sudan Meteorite
It revealed that this is of course the first meteorite has been recovered from an object that was detected in advance (about 24 hours lead time). With some prodding from me, it was revealed to be a fairly rare class of meteorite, an F class (about 1.3% of recoeverd meteorites) and specifically a Ureilite.
About Ureilites:
The ureilite class is named after the type example Novo-Urei, Russia that fell in 1886 and is one of the strangest of meteorites. Ureilites contain olivine and pyroxenes (pigeonite, augite, or orthopyroxene, depending on the sample) with filling of the intergranular spaces by graphite (rarely, tiny diamonds), Fe metal with very low Ni, sulfides, Fe3C and minor accessory phases. These minerals form ugly, dark, opaque masses that we refer to as carbonaceous-metal-silicate-masses or CMSM. Mineral rims and internal fractures appear to be encrusted with carbon (graphite) and tiny metal grains. Iron in the metal probably originated by reduction of oxidized iron (FeO) in silicates by reaction with graphite at some moderate to high temperature. Diamonds may have formed from graphite via impact-induced solid-state transformation, although it is more likely that they formed by vapor deposition.
Their origin is highly controversial. One school of thought is that they were formed in the interior of a parent body with cumulate crystals that formed crystal layers. Evidence of this is shown in some ureilites ( shown below) where grains are aligned in preferred orientation. A counter suggestion is that they represent a residuum of unmelted material after a partial melt liquid was drawn off (like ham hocks after the broth is removed). Other ideas are that they are unprocessed materials and never melted or they are mixtures of carbonaceous chondrite and basaltic rock melts.
Probably more than 80% of ureilites are classified as typical, characterized by olivine and pyroxene grains that are < one mm in size, anhedral with 120° triple junctions, and are devoid of plagioclase. A small number of poikilitic grains may be present (pyroxene grains included in olivine or the reverse association). Mosaicized ureilites are typified by finer grain size, probably as the result of recrystallization from shock. A few ureilites are classified as bimodal and are extremely heterogeneous with respect to grain size and mineral content. Some pyroxene grains may reach one to nearly two cm in size.
From http://www4.nau.edu/meteorite/Meteorite ... ilite.html
Further research is needed to unravel the mystery of the origin of the ureilites and the complex history of their parent body
It revealed that this is of course the first meteorite has been recovered from an object that was detected in advance (about 24 hours lead time). With some prodding from me, it was revealed to be a fairly rare class of meteorite, an F class (about 1.3% of recoeverd meteorites) and specifically a Ureilite.
About Ureilites:
The ureilite class is named after the type example Novo-Urei, Russia that fell in 1886 and is one of the strangest of meteorites. Ureilites contain olivine and pyroxenes (pigeonite, augite, or orthopyroxene, depending on the sample) with filling of the intergranular spaces by graphite (rarely, tiny diamonds), Fe metal with very low Ni, sulfides, Fe3C and minor accessory phases. These minerals form ugly, dark, opaque masses that we refer to as carbonaceous-metal-silicate-masses or CMSM. Mineral rims and internal fractures appear to be encrusted with carbon (graphite) and tiny metal grains. Iron in the metal probably originated by reduction of oxidized iron (FeO) in silicates by reaction with graphite at some moderate to high temperature. Diamonds may have formed from graphite via impact-induced solid-state transformation, although it is more likely that they formed by vapor deposition.
Their origin is highly controversial. One school of thought is that they were formed in the interior of a parent body with cumulate crystals that formed crystal layers. Evidence of this is shown in some ureilites ( shown below) where grains are aligned in preferred orientation. A counter suggestion is that they represent a residuum of unmelted material after a partial melt liquid was drawn off (like ham hocks after the broth is removed). Other ideas are that they are unprocessed materials and never melted or they are mixtures of carbonaceous chondrite and basaltic rock melts.
Probably more than 80% of ureilites are classified as typical, characterized by olivine and pyroxene grains that are < one mm in size, anhedral with 120° triple junctions, and are devoid of plagioclase. A small number of poikilitic grains may be present (pyroxene grains included in olivine or the reverse association). Mosaicized ureilites are typified by finer grain size, probably as the result of recrystallization from shock. A few ureilites are classified as bimodal and are extremely heterogeneous with respect to grain size and mineral content. Some pyroxene grains may reach one to nearly two cm in size.
From http://www4.nau.edu/meteorite/Meteorite ... ilite.html
Further research is needed to unravel the mystery of the origin of the ureilites and the complex history of their parent body
Re: NASA Teleconference about Sudan Meteorite
That's what I mean. Perhaps by examining these samples they might be able to determine their origin and uncover more about the development of our solar system.
That's what I mean. Perhaps by examining these samples they might be able to determine their origin and uncover more about the development of our solar system.
Re: For you space rock watchers...
http://www.space.com/searchforlife/0910 ... eroid.html
The asteroid that crashed in northern Sudan last year was shaped like a loaf of walnut-raisin bread, according to astronomer Peter Scheirich and colleagues at Ondrejov Observatory and Charles University in the Czech Republic.
............
Scheirich reported his findings at the Division for Planetary Sciences of the American Astronomical Society meeting in Puerto Rico on Oct. 5, 2009 in a special session dedicated to this asteroid one year after the fall. The small asteroid, designated "2008 TC3", was the first to have been spotted in space before hitting Earth.
An irregular shape and rapid tumbling caused Asteroid 2008 TC3 to flicker when it reflected sunlight on approach to Earth. Astronomers Marek Kozubal and Ron Dantowitz of Clay Center Observatory in Brookline, Massachusetts, tracked the asteroid with a telescope and captured the flicker of light during a two-hour period just before impact. Scheirich combined these observations with others to work out the shape and orientation of the asteroid.
.............
Other forensic evidence, which was presented during the special session at the AAS/DPS meeting, chaired by Jason S. Herrin of NASA Johnson Space Center and me, is based on analysis of the recovered meteorites. These are of an unusual "polymict ureilite" type. Herrin confirms that the meteorites still carry traces of being heated to 1150-1300 ºC, before rapidly cooling down at a rate of tens of °C per hour, during which carbon in the asteroid turned part of the olivine mineral iron into metallic iron. Hence, Asteroid 2008 TC3 is the remains of a minor planet that endured massive collisions billions of years ago, melting some of the minerals, but not all, before a final collision shattered the planet into asteroids.
Mike Zolensky of NASA's Johnson Space Center first pointed out that, as far as ureilites are concerned, this meteorite is unusually rich in pores, with pore walls coated by crystals of the mineral olivine. He now reports from X-ray tomography work with Jon Friedrich of Fordham University in New York, that those pores appear to outline grains that have been incompletely welded together and the pore linings appear to be vapor phase deposits. According to Zolensky, "2008 TC3 may represent an agglomeration of coarse- to fine-grained incompletely reduced pellets formed during impact, and subsequently welded together at high temperature."
http://www.space.com/searchforlife/0910 ... eroid.html
The asteroid that crashed in northern Sudan last year was shaped like a loaf of walnut-raisin bread, according to astronomer Peter Scheirich and colleagues at Ondrejov Observatory and Charles University in the Czech Republic.
............
Scheirich reported his findings at the Division for Planetary Sciences of the American Astronomical Society meeting in Puerto Rico on Oct. 5, 2009 in a special session dedicated to this asteroid one year after the fall. The small asteroid, designated "2008 TC3", was the first to have been spotted in space before hitting Earth.
An irregular shape and rapid tumbling caused Asteroid 2008 TC3 to flicker when it reflected sunlight on approach to Earth. Astronomers Marek Kozubal and Ron Dantowitz of Clay Center Observatory in Brookline, Massachusetts, tracked the asteroid with a telescope and captured the flicker of light during a two-hour period just before impact. Scheirich combined these observations with others to work out the shape and orientation of the asteroid.
.............
Other forensic evidence, which was presented during the special session at the AAS/DPS meeting, chaired by Jason S. Herrin of NASA Johnson Space Center and me, is based on analysis of the recovered meteorites. These are of an unusual "polymict ureilite" type. Herrin confirms that the meteorites still carry traces of being heated to 1150-1300 ºC, before rapidly cooling down at a rate of tens of °C per hour, during which carbon in the asteroid turned part of the olivine mineral iron into metallic iron. Hence, Asteroid 2008 TC3 is the remains of a minor planet that endured massive collisions billions of years ago, melting some of the minerals, but not all, before a final collision shattered the planet into asteroids.
Mike Zolensky of NASA's Johnson Space Center first pointed out that, as far as ureilites are concerned, this meteorite is unusually rich in pores, with pore walls coated by crystals of the mineral olivine. He now reports from X-ray tomography work with Jon Friedrich of Fordham University in New York, that those pores appear to outline grains that have been incompletely welded together and the pore linings appear to be vapor phase deposits. According to Zolensky, "2008 TC3 may represent an agglomeration of coarse- to fine-grained incompletely reduced pellets formed during impact, and subsequently welded together at high temperature."
The National Geographic Channel is running (right now) a show on the Naked Science series about this asteroid and it's discovery and recovery. It reruns tomorrow (Monday) at 5PM EDT.
Edit: Overall, the show was excellent, with great images of the recovered pieces, and very good scientific content.
Two complaints about the show (I always review any "science" show for accuracy)
The major one is that they never say that the proper name for the asteroid is 2008 TC3. There are many TC3 asteroids discovered in different years. The preceeding 2008 is needed identify the specific asteroid.
Second, as is common on depictions of the main asteroid belt and Kuiper belt, the density and size of the asteroids shown was off by dozens of orders of magnitude.
It was great to see Dr Petrus Jenniskens for more than a few seconds, and to sense his real enthusiasm on the subject. It's always nice to see those you have corresponded with via e-mail as animate beings
MW
Edit: Overall, the show was excellent, with great images of the recovered pieces, and very good scientific content.
Two complaints about the show (I always review any "science" show for accuracy)
The major one is that they never say that the proper name for the asteroid is 2008 TC3. There are many TC3 asteroids discovered in different years. The preceeding 2008 is needed identify the specific asteroid.
Second, as is common on depictions of the main asteroid belt and Kuiper belt, the density and size of the asteroids shown was off by dozens of orders of magnitude.
It was great to see Dr Petrus Jenniskens for more than a few seconds, and to sense his real enthusiasm on the subject. It's always nice to see those you have corresponded with via e-mail as animate beings
MW
Here's a list of references about 2008 TC3 (from NEODyS)
( 1) M.P.E.C. 2008-T50
( 2) Jenniskens, P. et al. (2009) Nature 458, 485-488. (The impact and recovery of asteroid 2008 TC3)
( 3) Scheirich, P. et al. (2009) DPS 41, 0904. (A Non-principal Axis Rotation of 2008 TC3)
( 4) Harris(JPL), A.W. & C.R. Chapman (2009) DPS 41, 4307. (Optical Detection of Small NEAs with Short Impact Warning) (2008TC3)
( 5) Borovicka, J. & Z. Charvat (2009) Astron.Astrophys. 507, 1015-1022. (Meteosat observation of the atmospheric entry of 2008 TC3 over Sudan and the associated dust cloud)
( 6) Jenniskens, P.M, et al. (2010) DPS 42, 6008. (abstract) (Almahata Sitta and the Rubble Pile Asteroid 2008 TC3)
( 7) Kohout, T. et al. (2010) DPS 42, 1329. (abstract) (2008 TC3 Asteroid Internal Structure and Physical Properties Inferred from Study of the Almahata Sitta Meteorites)
( 8) Freeman, W. et al. (2010) DPS 42, 1331. (abstract) (Investigation of the Origin of 2008TC3 Through Spectral Analysis of F-type Asteroids and Lab Spectra of Almahata Sitta and Mineral Mixtures )
( 9) Bishop, J.L. et al. (2010) DPS 42, 1330. (abstract) (Spectroscopy of Almahata Sitta and Goalpara Meteorites: Implications for Ureilite Composition and Association with Asteroids) (2008 TC3)
(10) SilvaBetzler, A. & A. BrumNovaes (2009) MPB 36, 145-147. (PHOTOMETRIC OBSERVATIONS OF 1998 OR2, 1999 AQ10, AND 2008 TC3)
(11) SilvaBetzler, A. et al. (2009) MPB 36, 58-59. (PHOTOMETRIC OBSERVATIONS OF EARTHIMPACTING 2008 TC3)
(12) Kidger, M.R. (2008) http://www.astrosurf.com/comets/neos/20 ... _light.htm (The lightcurve of 2008 TC3)
( 1) M.P.E.C. 2008-T50
( 2) Jenniskens, P. et al. (2009) Nature 458, 485-488. (The impact and recovery of asteroid 2008 TC3)
( 3) Scheirich, P. et al. (2009) DPS 41, 0904. (A Non-principal Axis Rotation of 2008 TC3)
( 4) Harris(JPL), A.W. & C.R. Chapman (2009) DPS 41, 4307. (Optical Detection of Small NEAs with Short Impact Warning) (2008TC3)
( 5) Borovicka, J. & Z. Charvat (2009) Astron.Astrophys. 507, 1015-1022. (Meteosat observation of the atmospheric entry of 2008 TC3 over Sudan and the associated dust cloud)
( 6) Jenniskens, P.M, et al. (2010) DPS 42, 6008. (abstract) (Almahata Sitta and the Rubble Pile Asteroid 2008 TC3)
( 7) Kohout, T. et al. (2010) DPS 42, 1329. (abstract) (2008 TC3 Asteroid Internal Structure and Physical Properties Inferred from Study of the Almahata Sitta Meteorites)
( 8) Freeman, W. et al. (2010) DPS 42, 1331. (abstract) (Investigation of the Origin of 2008TC3 Through Spectral Analysis of F-type Asteroids and Lab Spectra of Almahata Sitta and Mineral Mixtures )
( 9) Bishop, J.L. et al. (2010) DPS 42, 1330. (abstract) (Spectroscopy of Almahata Sitta and Goalpara Meteorites: Implications for Ureilite Composition and Association with Asteroids) (2008 TC3)
(10) SilvaBetzler, A. & A. BrumNovaes (2009) MPB 36, 145-147. (PHOTOMETRIC OBSERVATIONS OF 1998 OR2, 1999 AQ10, AND 2008 TC3)
(11) SilvaBetzler, A. et al. (2009) MPB 36, 58-59. (PHOTOMETRIC OBSERVATIONS OF EARTHIMPACTING 2008 TC3)
(12) Kidger, M.R. (2008) http://www.astrosurf.com/comets/neos/20 ... _light.htm (The lightcurve of 2008 TC3)
I really enjoyed the show (late to mention) primarily because it was (like yourself, after much correspondence with Dr. Jenniskens), the first time I'd heard him speak. Not at all what I'd envisioned [?] his voice sounding like.
Not at all what I'd envisioned [?] his voice sounding like.- Status
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