The news of the Winchcombe meteorite shower of February 28, 2021 can best be summed up by a quote that appeared in a National Geographic piece that appeared the following month; said the typically serene cosmochemist, Sara Russell, the lead researcher at the Planetary Materials Group at the Natural History Museum in London, “We’ve all just gone bananas!”

As described in the Meteoritical Bulletin (abridged):

“A bright fireball was observed blazing across the sky, travelling from approximately W to E over the United Kingdom at 21:54 (UT) on 28 February 2021. The fireball was recorded by 14 stations operated by the six meteor camera networks comprising the UK Fireball Alliance. It was also caught on numerous dashboard and doorbell cameras. There were over 1000 eyewitness accounts from across the entire UK, as well as Ireland and northern Europe, with reports of a sonic boom in the local area. The following morning, the Wilcock family discovered a pile of dark stones and powder on their driveway in the town of Winchcombe, Gloucestershire. Material from the impact site was collected into plastic bags that morning.”

The Bulletin goes on to describe who found what in the ensuing days, and the name that comes up most often is that of Chris Casey, an intrepid meteorite hunter who recovered multiple specimens over the course of a week. Now offered is one of Mr. Casey’s finds.

Winchcombe is a CM2 meteorite (it contains small chondrules, CAIs and hydrated minerals in a fine-grained carbon-rich, charcoal-hued matrix). Many CM2s are also rich in prebiotic compounds and amino acids. The presence of organic compounds has been detected in Winchcombe — initially by the sense of smell, where at least one stone was described as having a "compost-like" aroma.

While humans have 20 amino acids, the building blocks of proteins and life, nearly 100 amino acids have been found in CM2 meteorites — providing further impetus to the increasingly popular Panspermia Theory of Creation: fertilization on a cosmic scale with the precursors of life having been “seeded” on Earth by extraterrestrial impacts.
Stated Dr. Mark Sephton, an astrobiologist at London’s Imperial College, “The organic molecules in the [sample of Winchecombe] are older than the Earth itself, and similar molecules would have rained down on the early Earth before life emerged. They may represent the first chemical steps towards life in the early solar system, and could be the leftover ingredients from the recipe of life.”

As is the case with other CM2s, Winchcombe contains CAIs (Calcium Aluminum Inclusions), among the first materials to have formed in the solar nebula from which our solar system was created and the oldest matter humankind can see and touch.

Winchcombe evidences alteration from extraterrestrial water. Winchcombe is a breccia that contains both CM2 and CM1 lithologies — and CM1 meteorites are, apart from being the rarest variety known, are among the most water-rich; they contain secondary minerals that could only have formed as a result of aqueous alteration. Winchcombe is very similar to the material retrieved from the Japanese space probe Hayabusa2 following its visit to the near-Earth asteroid 162173 Ryugu in December 2020. As a result of all the camera angles of its descent, Winchcombe’s orbit around the sun has been precisely determined.

Only 602 grams of Winchcombe were ever found — and 90% of this material is controlled by The Natural History Museum in London. This is among the few opportunities to acquire a specimen of this historic meteorite, and this is a superior example.

Christie's would like to thank Dr. Alan E. Rubin at the Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles for his assistance in preparing this catalogue.
11 x 18 x 9mm (0.5 x 0.75 x 0.33 in.) and 3 grams (15.4 carats)

Chris Casey & Martin Goff, United Kingdom