ESA Planetary Defence Office’s NEO Coordination Centre (NEOCC) relies on the Aegis software to compute orbit determination and impact probabilities for asteroids monitored in the NEOCC portal. Aegis, which is developed and maintained by SpaceDyS s.r.l. under ESA contract and operated at the NEOCC, was initially introduced in a previous announcement. The software's operations and algorithms were also recently detailed in a publication in Celestial Mechanics and Dynamical Astronomy.

Aegis has now reached a significant milestone with the release of its latest version. Following months of rigorous testing, Aegis version 5 is now fully operational and actively producing results for the NEOCC portal. This latest release introduces several important enhancements, both in terms of scientific accuracy and computational efficiency.

From a data perspective, a major update is the improved treatment of visual magnitudes. Thanks to a new debiasing scheme developed by T. Hoffman, a former NEOCC intern, the system now provides more accurate brightness estimates, leading to better absolute magnitude determinations. Additionally, in anticipation of data from upcoming large-scale surveys like the Vera Rubin Observatory, Flyeye and NEO Surveyor, Aegis version 5 has been upgraded to ingest ADES-formatted astrometry. While not fully operational yet, some automated processing pipelines are already capable of handling these new datasets, ensuring a seamless integration of future observations into impact monitoring computations.

While these scientific updates are significant, some of the most impactful changes in Aegis version 5 occur under the hood. The software has been redesigned to operate in highly virtualized environments, making it more resilient to hardware infrastructure changes. Unlike previous versions, Aegis is no longer tied to a single computational node, significantly enhancing its adaptability and robustness. Furthermore, computational resource usage has been thoroughly optimized, allowing impact monitoring calculations to be performed faster than ever before. The system now runs on ESA’s private cloud infrastructure, ensuring improved performance, scalability, and security.

This new version of Aegis has already been used in the recent case of asteroid 2024 YR4, the asteroid that has represented the highest threat in the last 20 years. All our orbit determination and impact monitoring calculations were executed with version 5, yielding all the relevant information that ESA has provided in the last three months, as, for example, the figure accompanying this article which provides the evolution of the uncertainty region at the possible impact epoch in December 2032, as more observations were becoming available.

With all the above advancements, Aegis continues to evolve as a cutting-edge tool for asteroid orbit determination and impact risk assessment, reinforcing ESA’s commitment to planetary defence.

Evolution of the 3-sigma uncertainty region and impact probability of asteroid 2024 YR4 at the possible impact epoch on 22 December 2032, as more observations were becoming available day after day. Credit: ESA / PDO.