Expected Fragment Distribution from the First Interstellar Meteor CNEOS 2014-01-08

Abstract

In 2014, the fireball of the first interstellar meteor CNEOS 2014-01-08 (IM1) (Siraj & Loeb 2019), was detected off the northern coast of Papua New Guinea. A recently announced ocean expedition will retrieve any extant fragments by towing a magnetic sled across a 10 km x 10 km area of ocean floor approximately 300 km north of Manus Island (Siraj, Loeb, & Gallaudet 2022). We formulate a model that includes both the probabilistic mass distribution of meteor fragments immediately after the fragmentation event, the ablation of the fragments, and the geographic distribution of post-ablation fragments along the ground track trajectory of the bulk fragment cloud. We apply this model to IM1 to provide a heuristic estimate of the impactor's post-ablation fragment mass distribution, constructed through a Monte Carlo simulation. We find between ~8% and ~21% of fragments are expected to survive ablation with a mass $\geq$ .001 g, depending on the impactor's empirical yield strength. We also provide an estimation for the geographic distribution of post-ablation fragments.