The fall of the Grimsby meteorite—I: Fireball dynamics and orbit from radar, video, and infrasound records

Abstract– The Grimsby meteorite (H4–6) fell on September 25, 2009. As of mid‐2010, 13 fragments totaling 215 g have been recovered. Records of the accompanying fireball from the Southern Ontario Meteor Network, including six all‐sky video cameras, a large format CCD, infrasound and radar records, have been used to characterize the trajectory, speed, orbit, and initial mass of the meteoroid. From the four highest quality all‐sky video records, the initial entry velocity was 20.91 ± 0.19 km s−1 while the derived radiant has a local azimuth of 309.40° ± 0.19° and entry angle of 55.20° ± 0.13°. Three major fragmentation episodes are identified at 39, 33, and 30 km height, with corresponding uncertainties of approximately 2 km. Evidence for early fragmentation at heights of approximately 70 km is found in radar data; dynamic pressure of this earliest fragmentation is near 0.1 MPa while the main flare at 39 km occurred under ram pressures of 1.5 MPa. The fireball was luminous to at least 19.7 km altitude and the dynamic mass estimate of the largest remaining fragment at this height is approximately several kilograms. The initial mass is constrained to be <100 kg from infrasound data and ablation modeling, with a most probable mass of 20–50 kg. The preatmospheric orbit is typical of an Apollo asteroid with a likely immediate origin in either the 3:1 or ν6 resonances.

[1]  J. Borovička,et al.  Very low strengths of interplanetary meteoroids and small asteroids , 2011 .

[2]  P. Brown,et al.  Noble Gas Analysis of the Grimsby H Chondrite , 2010 .

[3]  J. Borovička,et al.  Analysis of instrumental observations of the Jesenice meteorite fall on April 9, 2009 , 2010 .

[4]  D. K. Wong,et al.  A meteoroid stream survey using the Canadian Meteor Orbit Radar II: Identification of minor showers using a 3D wavelet transform , 2010 .

[5]  P. Brown,et al.  Fall of the Grimsby H5 Chondrite , 2010 .

[6]  M. Fries,et al.  Partly Cloudy with a Chance of Chondrites — Studying Meteorite Falls Using Doppler Weather Radar , 2010 .

[7]  P. Brown,et al.  Development of an All-Sky Video Meteor Network in Southern Ontario, Canada The ASGARD System , 2010 .

[8]  Douglas R. Christie,et al.  The IMS Infrasound Network: Design and Establishment of Infrasound Stations , 2010 .

[9]  G. Sarty,et al.  Pre-fall Orbit of the Buzzard Coulee Meteoroid , 2010 .

[10]  Terence P. McClafferty,et al.  An Anomalous Basaltic Meteorite from the Innermost Main Belt , 2009, Science.

[11]  S. N. Milam,et al.  The impact and recovery of asteroid 2008 TC3 , 2009, Nature.

[12]  P. Jandir,et al.  ESTIMATING THE DRAG COEFFICIENTS OF METEORITES FOR ALL MACH NUMBER REGIMES. , 2009 .

[13]  Larry Denneau,et al.  Detection of Earth-impacting asteroids with the next generation all-sky surveys , 2009, 0905.3685.

[14]  Sigrid Close,et al.  Plasma and Electromagnetic Simulations of Meteor Head Echo Radar Reflections , 2008 .

[15]  P. Brown,et al.  The Southern Ontario All-sky Meteor Camera Network , 2008 .

[16]  D. Revelle,et al.  Infrasonic Observations of Meteoroids: Preliminary Results from a Coordinated Optical-radar-infrasound Observing Campaign , 2008 .

[17]  James Jones,et al.  A meteoroid stream survey using the Canadian Meteor Orbit Radar: I. Methodology and radiant catalogue , 2008 .

[18]  A. Pichon,et al.  Infrasound Event Detection Using the Progressive Multi-Channel Correlation Algorithm , 2008 .

[19]  Kazuya Yoshida,et al.  Touchdown of the Hayabusa Spacecraft at the Muses Sea on Itokawa , 2006, Science.

[20]  D. Revelle,et al.  Estimates of meteoroid kinetic energies from observations of infrasonic airwaves , 2006 .

[21]  J. A. Docobo,et al.  The Villalbeto de la Peña meteorite fall: II. Determination of atmospheric trajectory and orbit , 2006 .

[22]  P. Brown,et al.  The fall and recovery of the Tagish Lake meteorite , 2006 .

[23]  J. Jonesa,et al.  The Canadian Meteor Orbit Radar : system overview and preliminary results , 2005 .

[24]  D. Revelle,et al.  The orbit, atmospheric dynamics, and initial mass of the Park Forest meteorite , 2004 .

[25]  W. Edwards,et al.  SUPRACENTER: Locating fireball terminal bursts in the atmosphere using seismic arrivals , 2004 .

[26]  Clark R. Chapman,et al.  SPACE WEATHERING OF ASTEROID SURFACES , 2004 .

[27]  Sigrid Close,et al.  A technique for calculating meteor plasma density and meteoroid mass from radar head echo scattering , 2004 .

[28]  H. Haak,et al.  Tracing a meteoric trajectory with infrasound , 2003 .

[29]  J. Borovička,et al.  The Morávka meteorite fall: 4. Meteoroid dynamics and fragmentation in the atmosphere , 2003 .

[30]  J. Borovička,et al.  The Morávka meteorite fall: 1. Description of the events and determination of the fireball trajectory and orbit from video records , 2003 .

[31]  Jürgen Oberst,et al.  Photographic observations of Neuschwanstein, a second meteorite from the orbit of the Příbram chondrite , 2003, Nature.

[32]  R. Jedicke,et al.  Debiased Orbital and Absolute Magnitude Distribution of the Near-Earth Objects , 2002 .

[33]  Eric P. Chael,et al.  VERSION 1.7 OF MATSEIS AND THE GNEM R&E REGIONAL SEISMIC ANALYSIS TOOLS , 2002 .

[34]  Douglas O. ReVelle,et al.  Meteor Phenomena and Bodies , 1998 .

[35]  James Jones,et al.  An improved interferometer design for use with meteor radars , 1998 .

[36]  D. Revelle,et al.  The fall of the St-Robert meteorite , 1996 .

[37]  Z. Ceplecha.  Luminous efficiency based on photographic observations of the Lost City fireball and implications for the influx of interplanetary bodies onto Earth. , 1996 .

[38]  A. Taylor,et al.  A New Technique for Radar Meteor Speed Determination: Inter-Pulse Phase Changes from Head Echoes , 1996 .

[39]  Jiri Borovicka,et al.  A new positional astrometric method for all-sky cameras. , 1995 .

[40]  Richard Swinbank,et al.  A Stratosphere-Troposphere Data Assimilation System , 1994 .

[41]  P. Brown,et al.  The orbit and atmospheric trajectory of the Peekskill meteorite from video records , 1994, Nature.

[42]  Timothy D. Crum,et al.  The WSR-88D and the WSR-88D Operational Support Facility , 1993 .

[43]  J. Borovička,et al.  Atmospheric fragmentation of meteoroids , 1993 .

[44]  C. Keay.  Electrophonic sounds from large meteor fireballs , 1992 .

[45]  J. Borovička.  The comparison of two methods of determining meteor trajectories from photographs , 1990 .

[46]  Zdenek Ceplecha,et al.  Geometric, dynamic, orbital and photometric data on meteoroids from photographic fireball networks , 1987 .

[47]  George W. Wetherill,et al.  Which fireballs are meteorites? A study of the Prairie Network photographic meteor data , 1981 .

[48]  I. Halliday,et al.  THE INNISFREE METEORITE FALL: A PHOTOGRAPHIC ANALYSIS OF FRAGMENTATION, DYNAMICS AND LUMINOSITY , 1981 .

[49]  D. Lal,et al.  Multiple fall of Pribram meteorites photographed. XII - Pre-atmospheric size of the Pribram meteorite based on studies of fossil cosmic ray tracks and spallation products , 1980 .

[50]  D. Revelle,et al.  On the luminous efficiency of meteoritic fireballs , 1979 .

[51]  M. Skolnik,et al.  Introduction to Radar Systems , 2021, Advances in Adaptive Radar Detection and Range Estimation.

[52]  I. Halliday,et al.  The Innisfree Meteorite and the Canadian Camera Network , 1978 .

[53]  G. Consolmagno,et al.  Composition and evolution of the eucrite parent body - Evidence from rare earth elements. [extraterrestrial basaltic melts] , 1977 .

[54]  Z. Ceplecha,et al.  Fireball end heights: A diagnostic for the structure of meteoric material , 1976 .

[55]  D. Revelle,et al.  Meteor-generated infrasound. , 1976, Science.

[56]  D. Revelle.  Acoustics of meteors : effects of the atmospheric temperature and wind structure on the sounds produced by meteors : technical report ; part 2: effects of atmospheric refraction and attenuation considerations. , 1973 .

[57]  R. E. Mccrosky,et al.  Lost City meteorite—Its recovery and a comparison with other fireballs , 1971 .

[58]  J. Gillis,et al.  Methods in Computational Physics , 1964 .

[59]  Ely M. Gelbard,et al.  Methods in Computational Physics, Vol. I , 1964 .

[60]  Z. Ceplecha.  Multiple fall of Přibram meteorites photographed. 1. Double-station photographs of the fireball and their relations to the found meteorites , 1961 .