The fireball of 21/09/2017: A study of eyewitness reports

On September 21, 2017, a large fireball appeared over the Netherlands and vanished over the North Sea. Scores of eyewitness reports with descriptions of the phenomenon arrived through our notification e-mail address feuerkugel@dlr.de. By studying these reports, given with varying level of details, and by comparing them with other trusted sources we may appreciate how reliable and complete the reported data are. This might be helpful for us to improve our notification system in the future. Also, reports sometimes include information not easily obtained by other observing techniques. On the other hand, the reporting system is useful to promote public awareness of Earth in the environment of space.