Context. Until recently, camera networks designed for monitoring fireballs worldwide were not fully automated, implying that in case of a meteorite fall, the recovery campaign was rarely immediate. This was an important limiting factor as the most fragile – hence precious – meteorites must be recovered rapidly to avoid their alteration. Aims. The Fireball Recovery and InterPlanetary Observation Network (FRIPON) scientific project was designed to overcome this limitation. This network comprises a fully automated camera and radio network deployed over a significant fraction of western Europe and a small fraction of Canada. As of today, it consists of 150 cameras and 25 European radio receivers and covers an area of about 1.5 × 106 km2. Methods. The FRIPON network, fully operational since 2018, has been monitoring meteoroid entries since 2016, thereby allowing the characterization of their dynamical and physical properties. In addition, the level of automation of the network makes it possible to trigger a meteorite recovery campaign only a few hours after it reaches the surface of the Earth. Recovery campaigns are only organized for meteorites with final masses estimated of at least 500 g, which is about one event per year in France. No recovery campaign is organized in the case of smaller final masses on the order of 50 to 100 g, which happens about three times a year; instead, the information is delivered to the local media so that it can reach the inhabitants living in the vicinity of the fall. Results. Nearly 4000 meteoroids have been detected so far and characterized by FRIPON. The distribution of their orbits appears to be bimodal, with a cometary population and a main belt population. Sporadic meteors amount to about 55% of all meteors. A first estimate of the absolute meteoroid flux (mag < –5; meteoroid size ≥~1 cm) amounts to 1250/yr/106 km2. This value is compatible with previous estimates. Finally, the first meteorite was recovered in Italy (Cavezzo, January 2020) thanks to the PRISMA network, a component of the FRIPON science project.

A detailed ion-neutral chemistry model named MiPO-Streamer model has been developed to simulate the impact of blue jet streamers on stratospheric chemistry. It is based on the MiPLaSMO model (Microphysical and Photochemical Lagrangian Stratospheric Model of Ozone) widely used over the last 20 years to interpret balloon and satellite measurements associated with stratospheric ozone. In this study, instead of using a reduced electric field with constant value during blue jet streamer discharge process, we used a time-dependent reduced electric field coming from an explicit streamer model. The simulations are performed on daytime/nighttime and in 2-day long-term duration at 27 km where the catalytic cycle of NO x is the most efficient to destroy ozone. Among 117 species considered, we put the focus on nitrogen, oxygen, chlorine, and bromine species, and ozone perturbation. The model results indicate that the densities of neutral species through an electrodynamic streamer simulation show an impact of a factor 2 as compared to the pulse-based simulation at 27 km.

Fishman et al. (1994) discovered bright, short bursts of gamma-rays emerging from thunderclouds on Earth in the data from the Burst and Transient Source Experiment (BATSE) instrument aboard the Compton Gamma-Ray Observatory. These sub-millisecond bursts were dubbed Terrestrial Gamma-ray Flashes (TGFs), and have since been observed by several spacecraft, notably RHESSI (