IAWN GLOBAL PLANETARY DEFENSE NEA CHARACTERIZATION CAMPAIGNS

The International Asteroid Warning Network (IAWN) has been conducting global planetary defense campaigns involving real near-Earth asteroids (NEAs) since 2017. Thus far, six campaigns have been conducted with NEAs 2012 TC4, 1999 KW4 (66391 Moshup), 99942 Apophis, 2019 XS, 2005 LW3, and 2023 DZ2. The goal of these campaigns is to exercise the global planetary defense system (observers, modelers, decision makers) to improve our ability to respond to a future impact hazard. Two of the campaigns (2019 XS and 2005 LW3) were devoted to identifying and correcting errors in the timing information when the data were collected. However, the majority of the campaigns have been dedicated to physical characterization of the NEAs. Data were collected to define the compositions, shapes, sizes, thermal properties, rotation periods, taxonomy, and possible meteorite analogs. Both ground-based observatories around the world and space-based assets were used in to make the measurements.

Previously, campaign participants were provided ample lead time (weeks to months) to get organized prior to the close approaches of the NEAs. This permitted the many campaign participants to organize ahead of time into working groups based on the type of data to be collected, typically photometry, spectroscopy, radar, thermal modeling/polarimetry, and hazard modeling. It also allowed for telescope time to be secured and personnel work schedules to be adjusted to participate in the campaign. However, in the real-world case of a short-term close approach or an imminent hazard, there might not be lengthy lead time to prepare an observing campaign for an incoming object. So, it has long been desired to conduct a campaign on very short notice. Thus, in the latest campaign involving 2023 DZ2, the IAWN community was given only about two days’ notice to begin their observations and the campaign was limited to just over one week.

Enthusiastic participation in the campaigns has been outstanding with typically more than a dozen nations represented and as many as a hundred participants involved in the observations. In this presentation we will summarize the results and lessons learned from the NEA characterization campaigns, focusing on the latest exercise with 2023 DZ2.

Acknowledgement: We thank all observers who contributed to the campaigns but could not be included in the author list due to the abstract length limit.