The ESA Meerkat Asteroid Guard: a monitoring service for imminent impactors

TL;DR

The ESA Meerkat Asteroid Guard is a monitoring service that uses systematic ranging and statistical analysis to detect, assess, and warn about imminent asteroid impact threats in real-time.

Contribution

It introduces a comprehensive automated system combining orbit determination, impact probability estimation, and follow-up guidance for near-Earth object monitoring.

Findings

Successfully warned about all six past imminent impactors before impact.

Provided alerts for scientifically interesting events and close approaches.

Operated effectively over five years with consistent performance.

Abstract

We present the Meerkat Asteroid Guard, an imminent impactor warning service developed and maintained by the European Space Agency's Near-Earth Object Coordination Centre (NEOCC). The software uses the method of systematic ranging to perform orbit determination on tracklets in the Near-Earth Object Confirmation Page (NEOCP), which typically have short observational arcs. Fitted orbits are propagated to determine the likelihood of an impact with Earth. In addition, magnitude fitting and Monte Carlo sampling are performed to estimate the object's size, possible impact locations and times, and suggest a best telescope pointing for object follow-up. A set of object scores are produced from computed posterior probabilities across the grid, giving a statistical description of the object's orbital and physical characteristics. The scores are packaged with several informative plots in an email alert, which is sent to Meerkat subscribers in the event of a significant impact probability, close approach, or other scientifically interesting event. The highlights of the five years of Meerkat's operational service are presented, including the successful warnings for all of the past six imminent impactors discovered before impact and several interesting close approaches.