Back on February 28, 2020, a fireball was seen in parts of eastern Europe such as Slovenia, Croatia, Austria, and Hungary in the morning sky. The path actually went right over Slovenia, where people reported explosions, a long flash, and a visible dust trail. Then, people started reporting their experiences online and uploading videos from dashcams, security cameras, and a cyclist’s helmet-cam. Using all of the data collected, scientists were able to not only trace the path of the fireball through the sky but also recover fragments, including three fragments that come to about 720 grams of space rock. The largest fragment seen in the videos is estimated to be about 10 kilograms but has yet to be found.

Dr. Denis Vida from the University of Western Ontario presented the findings, explaining: By combining observations from several cameras around 100 kilometers apart, a fireball’s position can be pinpointed to within 50 meters, and it’s usually fairly easy to compute its atmospheric trajectory and pre-atmospheric orbit this way. The fireball’s path is in a volume of the world’s sky among the most densely observed by specialist night-operating cameras. Its path would have been caught by at least 20 if it happened just a few hours earlier. But because this fireball occurred during the day and was recorded by dash cameras moving up to 70 kilometers per hour, we required a different approach.

On top of all the video footage they did have, local people became community scientists by taking pictures of buildings, telephone poles, mountains, and other landmarks in the videos, which were then analyzed to determine the exact track and location of the fragments. Yay, science!

More Information

ESPC press release

“Novo Mesto meteorite fall – trajectory, orbit, and fragmentation analysis from optical observations,” Denis Vida et al., 2021 September 13-24, European Planetary Science Congress 2021