The Winchcombe fireball-That lucky survivor

On February 28, 2021, a fireball dropped similar to 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 (similar to 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 (similar to 0.6 MPa) due to a fortuitous combination of entry parameters, notably low velocity (13.9 km s-1). A near-catastrophic fragmentation at similar to 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 similar to 0.08 Myr ago and it never had a perihelion distance smaller than similar to 0.7 AU, while other CM2 meteorites with known orbits approached the Sun closer (similar to 0.5 AU) and were heated to at least 100 K higher temperatures.