2022 WJ1

Automated detection

MetDetect searched the KBUF radar around the fireball time. It found the fall: the radar cells it reports are mostly the debris identified by hand.

• 31of the 486 hand-identified cells on KBUF found
• 455hand-identified cells missed
• 0cells reported that were not identified by hand

MetDetect RUN-41, 29 Oct 2026. Leave one fall out: every learned part was trained without the fall it is scored on. The design falls were used to develop the method, so their scores are development results; the held-out falls were not. Hand-identified cells on KBUF outside the data the search loads, not counted: 4. The hand identification is the reference these numbers are graded against.

Dark flight

After the fireball goes dark, meteorites fall freely through the wind. Each radar cell is flown down to the ground through the winds of that day; the coloured areas show where stones of each mass most likely landed, and the black line runs from light to heavy stones (solid where the radar traced it, dashed where extended).

Pixel estimate, computed by P. Shober with MetDetect: winds from ERA5 (ECMWF), masses for an ordinary-chondrite density over a range of shapes. Preliminary: it does not fit the fireball itself, so the heavy end of the line is an extrapolation.

Human identification

The radar signatures of this fall were identified by hand by Marc Fries (NASA ARES, Johnson Space Center). Read the original report (archived copy).

Meteorites

No meteorites confirmed. The small asteroid 2022 WJ1 was found by telescope hours before impact; most of the debris fell into Lake Ontario.

Publications

Kareta T., Vida D., Micheli M., et al. (2024) Telescope-to-Fireball Characterization of Earth Impactor 2022 WJ1. The Planetary Science Journal 5, 253

Know of a paper or a recovered meteorite we missed? Tell us.