The “European Fireball Network”: Current status and future prospects

Abstract

Abstract— Among the three large camera networks carrying out fireball observations through the seventies and eighties, the “European Fireball Network” is the last one still in operation. The network today consists of more than 34 all‐sky and fish‐eye cameras deployed with ∼100 km spacing and covering an area of ∼106 km2, in the Czech and Slovak Republics, Germany, as well as parts of Belgium, Switzerland, and Austria. Network operation results in ∼10 000 image exposures per year, which represent on average 1200 h of clear sky observations—as imaging periods are restricted due to daylight, moonlight, and clouds. The cameras detect currently large meteors at a rate of ∼50 per year; this is in good agreement with the encounter rates determined in previous fireball studies. From sightings of “meteorite candidates” (fireballs that may have deposited meteorites) and meteorite recoveries in the network area, we estimate that 15% of the influx of meteoritic matter is currently observed by the cameras, whereas <1% is recovered on the ground. Issues to be addressed by future fireball observations include the study of very large meteoroids (>1000 kg) for which statistics are currently very poor and an examination of their relationship to NEOs (near‐Earth objects) identified by current NEO search programs.

Exogenic Dynamics, Cratering, and Surface Ages

“…By analyzing real collisions of small and hence frequent enough bodies colliding with the Earth atmosphere and observed as bolides (Morbidelli and Gladman, 1998), the statistical investigation of impact probability for small NEOs can be extended. Systematic photographic surveys of bolides have been made in different countries in different periods of time (Borovicka et al, 2005;Ceplecha, 1987;Halliday et al, 1996;McCrosky et al, 1978;Oberst et al, 1998). Registration of each event from several observational points allows researchers to estimate orbital parameters just before the atmospheric entry.…”

Infrasonic Observations of Meteoroids: Preliminary Results from a Coordinated Optical-radar-infrasound Observing Campaign

“…Recent observations using the European Fireball Network (Oberst et al 1998) and the IMS station I26DE showed that high altitude infrasound from shower meteors was possible. This more complete and general survey suggests that not only is infrasound production possible at these altitudes, it appears that it is quite common for meteors \-4 magnitude with at least 8 of 18 signals originating at altitudes [80 km.…”

Thermal stresses in small meteoroids

“…As an example, we mention the results from the European networks overviewed by Oberst et al (1998). Focusing on the brightest recorded bolides, we note several group-IIIb meteors of an estimated meter-range pre-atmospheric size and low perihelia.…”