The Winchcombe fireball—that lucky survivor

McMullan, S. et al. (2023) The Winchcombe fireball—that lucky survivor. Meteoritics and Planetary Science, (doi: 10.1111/maps.13977) (Early Online Publication)

Abstract

On February 28, 2021, a fireball dropped ∼0.6 kg of recovered CM2 carbonaceous chondrite meteorites in South-West England near the town of Winchcombe. We reconstruct the fireball's atmospheric trajectory, light curve, fragmentation behavior, and pre-atmospheric orbit from optical records contributed by five networks. The progenitor meteoroid was three orders of magnitude less massive (∼13 kg) than any previously observed carbonaceous fall. The Winchcombe meteorite survived entry because it was exposed to a very low peak atmospheric dynamic pressure (∼0.6 MPa) due to a fortuitous combination of entry parameters, notably low velocity (13.9 km s−1). A near-catastrophic fragmentation at ∼0.07 MPa points to the body's fragility. Low entry speeds which cause low peak dynamic pressures are likely necessary conditions for a small carbonaceous meteoroid to survive atmospheric entry, strongly constraining the radiant direction to the general antapex direction. Orbital integrations show that the meteoroid was injected into the near-Earth region ∼0.08 Myr ago and it never had a perihelion distance smaller than ∼0.7 AU, while other CM2 meteorites with known orbits approached the Sun closer (∼0.5 AU) and were heated to at least 100 K higher temperatures.

• Item Type: Articles
• Additional Information: STFC are acknowledged for supporting the "Curation and Preliminary Examination of the Winchcombe Carbonaceous Chondrite Fall" project (ST/V000799/1), and Natural History Museum staff for curatorial support. The Curtin University authors acknowledge their contribution was made possible by the Australian Research Council as part of the Australian Discovery Project scheme (DP170102529, DP200102073), the Linkage Infrastructure, Equipment and Facilities scheme (LE170100106), and through institutional support from Curtin University. The Global Fireball Observatory data reduction is supported by resources provided by the Pawsey Supercomputing Centre with funding from the Australian Government and the Government of Western Australia, and makes intensive use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013). This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 945298. DV was funded by the NASA Meteoroid Environment Office under cooperative agreement 80NSSC21M0073. Several authors acknowledge funding from UK Science and Technology Facilities Council; SM and GSC ST/S0000615/1, LD ST/T002328/1, and KJ ST/R000751/1. AK is funded by UK Research and Innovation Grant MR/T020261/1. LD thanks a University of Glasgow COVID-19-Research Support Scheme grant.
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Daly, Dr Luke and O'Brien, Ms Aine
• Authors: McMullan, S., Vida, D., Devillepoix, H. A.R., Rowe, J., Daly, L., King, A. J., Cupák, M., Howie, R. M., Sansom, E. K., Shober, P., Towner, M. C., Anderson, S., McFadden, L., Horák, J., Smedley, A. R.D., Joy, K. H., Shuttleworth, A., Colas, F., Zanda, B., O'Brien, Á., McMullan, I., Shaw, C., Suttle, A., Suttle, M. D., Young, J. S., Campbell-Burns, P., Kacerek, R., Bassom, R., Bosley, S., Fleet, R., Jones, D., McIntyre, M., James, N., Robson, D., Dickinson, P., Bland, P. A., and Collins, G. S.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Meteoritics and Planetary Science
• Publisher: Wiley
• ISSN: 1086-9379
• ISSN (Online): 1945-5100
• Published Online: 10 May 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Meteoritics and Planetary Science 2023
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.5281/zenodo.6685719

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
308251		UK leadership in extraterrestrial sample return	Martin Lee	Science and Technology Facilities Council (STFC)	ST/T002328/1	P&S - Physics & Astronomy