Meteorite falls in weather radar

How it works

1. A fireball breaks up

   Most of a meteoroid burns up. What survives slows down within seconds and stops glowing 15–40 km up. From there the stones fall in the dark for several minutes, drifting with the wind: the dark flight.

2. Weather radars see the stones

   NEXRAD radars scan the sky every few minutes. A shower of falling stones and dust can show up as faint, short-lived echoes that sink from one scan to the next, sometimes on several radars at once.

3. MetDetect searches automatically

   Given the fireball time and a search window, MetDetect looks for new echo at the right height and time, picks the candidate most like falling debris and grows it into the neighbouring radar cells. It was trained and tested one fall at a time, never on the fall being scored.

4. A person verifies it

   Automatic detections stay awaiting verification until someone has checked the radar data by hand. The human-verified falls here were identified by Marc Fries (NASA ARES); MetDetect is graded against his identifications.

5. Dark flight gives a search map

   Each radar cell is flown down through the winds of that day, which shows where stones of each mass most likely landed. Recovered meteorites are drawn on the maps afterwards, as a check.

See a fall in 3D in the MetDetect demo, or read about the research.