A physical survey of meteoroid streams: Comparing cometary reservoirs

Abstract

In this work, we present an optical survey of mm-sized meteoroids using the Canadian Automated Meteor Observatory’s (CAMO) mirror tracking system. The system tracks meteors to magnitude +7.5 through an image-intensified telescopic system which has a spatial accuracy of ∼1m and a temporal resolution of 10ms. We analyse 41 meteors from 13 showers with known parent bodies, recorded between 2016 and 2022. We fit a numerical ablation and fragmentation model to our data which models meteoroid fragmentation as erosion into 10µm to 500µm constituent grains and used the observed wake as a hard constraint on the model parameters. We measure average bulk meteoroid densities which are consistent with in situ measurements: 602 ±155kgm−3 for Jupiter-family and 345 ±48kgm−3 for Halley-type showers. The Geminids had the highest measured bulk density of 1387 ±240kgm−3, consistent with carbonaceous material. We fail to reproduce the high bulk density (>3000kgm−3) for Jupiter-family meteoroids previously reported in the literature derived using fragmentation models on data sets with fewer observational constraints. We also provide estimates of the meteoroid grain sizes, grain mass distributions, and energy necessary to trigger the erosion for meteoroids in the analysed showers.