Multi-parameter monitoring of the potential impact of the exercise asteroid 2024 PDC25

Regarding the most recent asteroid mitigation exercise during the 2025 Planetary Defense Conference (PDC), we note that, if the mitigation efforts do not succeed to alter the trajectory of (the fictitious object) 2024PDC25, the asteroid will impact the surface of the Earth along the border between the Democratic Republic of the Congo in the north and Angola in the south, possibly depositing up to 250 megatons (TNT equivalent) of energy and creating a crater of about 3 km in diameter. If such an event would actually happen, it would be of obvious interest to observe the impact in as much detail as possible. In such a case we propose to populate the impact area with suitable sensors and probes, ranging from drones in various altitudes in the atmosphere to the surface and below. The goal of this paper is to sketch out a first attempt at a strategy for these observations in terms of requirements, capabilities, feasibility, and data sampling and storage. The expected impact-related phenomena include electromagnetic interactions with the atmosphere and with the target material, pressure waves and acoustics in the air and on the ground, and events in the expanding plasma and in the fireball, which would be observable with suitable spectrometers. Seismic data can be combined with data from the UN Comprehensive Nuclear Test Ban Treaty Organization (CTBTO). High precision Global Navigation Satellite System data, using differential signal strategies, could also be useful, as are detailed satellite monitoring data, including using radar and radio signal monitoring instrumentation, which would also be of benefit. After an impact, an effort to reach the impact site to study the distribution of rock types and take a variety of samples, including monitoring the temperature development of the crater fill rock and other parameters, would be advantageous. The data can be collected in a suitable data base and combined with data obtained from satellites and other remote sensing platforms. In this manner a full digital model of the impact event could be constructed.