EU-ESA Workshop on Meteor Observations for Planetary Defence

The Global Meteor Network as a Planetary Defence Asset: Fireball Trajectories, Orbits, and the Physical Structure of Small Impactors from Citizen-Operated Cameras

3 Nov 2026, 16:00

25m

Petralia Sottana, Sicily

Optical fireball networks: capabilities and coordination

Speaker

Denis Vida (Department of Physics and Astronomy, Institute for Earth and Space Exploration, Western University, London, Ontario, Canada)

Description

The Global Meteor Network (GMN) is a distributed optical fireball network of more than 1,600 cameras in over 45 countries, operated by volunteers using consumer off-the-shelf security cameras and Raspberry Pi computers running the open-source RMS software. Trajectories, orbits, and calibrated photometry are published daily, and the full analysis toolchain is open source and independently reusable.
This contribution reviews what GMN can measure during an impactor response, and how well. The GMN provides multi-station trajectory reconstruction, orbit determination with numerical integration to pre-impact elements, absolute photometric lightcurves, semi-analytic fragmentation modelling that constrains bulk strength and fragment mass distribution, and dark-flight and strewn-field prediction using the best available wind models.
We illustrate performance with three imminent-impactor and meteorite-dropping cases. For 2022 WJ1, trajectories derived from meteor cameras and from MPC astrometry agreed to within 40 m, and fragmentation modelling independently supported a decimetre-scale, ordinary-chondrite-like body. Novo Mesto and 2023 CX1 demonstrate what fireball data reveal about internal structure: Novo Mesto disrupted abruptly near 35 km, shedding over 80% of its mass around 3 MPa, while 2023 CX1 catastrophically disrupted near 28 km and released 98% of its kinetic energy in a fraction of a second. Both dropped L chondrites, indicating a class of small impactors that fails at low dynamic pressure, directly relevant to airburst hazard assessment.
Beyond single events, GMN's homogeneous orbit and flux database constrains the centimetre-to-metre impactor population, its orbital sources, and seasonal detection biases.
We conclude with the reliability limits of each product and what would be required to operationalise GMN for planetary defence response: rapid-response tasking, reduced latency, standardised uncertainty reporting, and a sustained support model for an infrastructure currently sustained by volunteers.