[meteorite-list] Fusion Crusted "Meteoroids"
From: Jeff Kuyken <info_at_meteoritecentral.com>
Date: Thu, 26 Mar 2009 22:35:22 +1100 Message-ID: <826AA4EACA67403FAF2EC73200B7BCB5_at_JeffPC> You beat me to it Darren! ;-) That was going to be my example too. Some meteoroids do enter and exit the atmosphere again ("Earth Grazing") so there would be some out there with fusion crust. For anyone that hasn't seen the Grand Teton fireball, it's worth seeing: http://www.youtube.com/watch?v=7M8LQ7_hWtE Cheers, Jeff ----- Original Message ----- From: "Darren Garrison" <cynapse at charter.net> To: <meteorite-list at meteoritecentral.com> Sent: Thursday, March 26, 2009 3:57 AM Subject: Re: [meteorite-list] Fusion Crusted "Meteoroids" > On Wed, 25 Mar 2009 08:21:58 -0700, you wrote: > >>How many beautifully black and fully fusion crusted meteoroids and >>asteroids are floating around out there in space? > > A fusion crust is formed by the rapid melting and rapid resolidifying of > the > meteoroid, caused by heat generated by a meteoroid passing through the > atmosphere of a planet, decelerating, and having some of it's massive > amount of > kinetic energy converted to light, sound, and heat, due to conservation of > energy. So a meteroid in space with a fusion crust would have had to have > grazed deep enough in to the atmosphere of a planet or moon and then > skipped > back into space. Any attempt (by anyone, no matter how expert) to give an > approx. number of times that this has happened on all atmosphere-posessing > planets and moons AND the meteoroid wasn't destroyed on a later pass near > the > planet/moon AND it hasn't happened so long ago that the normal erosion in > space > has broken up that fusion crust would be a pure guess. This MIGHT be one: > > http://en.wikipedia.org/wiki/The_Great_Daylight_1972_Fireball > > I can imagine that a massive nearby gamma ray burst might also be able to > melt a > thin fusion crust around meteroids in space, but if such an event had > happened > in the recent geological past, we would have noticed it by the fact of all > being > dead. > ______________________________________________ > http://www.meteoritecentral.com > Meteorite-list mailing list > Meteorite-list at meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > > Received on Thu 26 Mar 2009 07:35:22 AM PDT |
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