Learning about comets from the study of mass distributions and fluxes of meteoroid streams

Abstract

Meteor physics can provide new clues about the size, structure, and density of cometary disintegration products, establishing a bridge between different research fields. From meteor magnitude data we have estimated the mass distribution of meteoroids from different cometary streams by using the relation between the luminosity and the mass obtained by Verniani (1973). These mass distributions are in the range observed for dust particles released from comets 1P/Halley and 81P/Wild 2 as measured from spacecraft. From the derived mass distributions, we have integrated the incoming mass for the most significant meteor showers. By comparing the mass of the collected Interplanetary Dust Particles (IDPs) with that derived for cometary meteoroids a gap of several orders of magnitude is encountered. The largest examples of fluffy particles are clusters of IDPs no larger than 100 µm in size (or 5×10 -7 g in mass) while the largest cometary meteoroids are centimeter-sized objects. Such gaps can be explained by the fragmentation in the interstellar medium or in the atmosphere of the original cometary particles. As an application of the mass distribution computations we describe the significance of the disruption of fragile comets in close approaches to Earth as a more efficient (and probably more frequent) way to deliver volatiles than direct impacts. We finally apply our model to quantify the flux of meteoroids from different meteoroid streams, and to describe the main physical processes contributing to the progressive decay of cometary meteoroids in the interplanetary medium.

The Spectrum and Orbit of a Fireball Producing Mesospheric Irregularity and Implications for Meteor Mass Deposition

“…By integrating dm along the optical path, the photometric mass of the meteoroid can be obtained. In fact, the determination of meteoroid mass from meteor brightness is a complex topic involving multiple dependencies and unknown parameters (e.g., Drolshagen et al 2021aDrolshagen et al , 2021bTrigo-Rodríguez & Blum 2022). For example, the values of luminous efficiency derived from different methods show a wide scatter ranging between 2 × 10 −4 and 4 × 10 -1 (Drolshagen et al 2021a, and the references therein).…”

Orbital characterization of superbolides observed from space: dynamical association with near-Earth objects, meteoroid streams and identification of hyperbolic projectiles

“…As suggested by the high tensile strengths obtained (in the known range of values for high strength chondrites and iron meteorites: 10 7 to 10 8 P a), and in agreement with (Siraj & Loeb 2022), it is perhaps more unlikely that submetric-sized meteoroids survive long stays in interstellar space due to the effect of thermal stress and cosmic radiation over millions of years in comparison with large objects (see Figure 2). The presence of refractory aggregates in the interstellar medium could progressively erode smaller fragile objects biasing cometary meteoroids, which, in turn, could be more common due to their eccentric orbits (Trigo-Rodríguez & Blum 2021). The identified CNEOS bolides were produced by roughly metersized rocks, but other two larger bodies have been recently identified: 1I/'Oumuamua or 2I/Borisov (Meech et al 2017;Guzik et al 2020).…”

Formation of Comets

“…Cometary trails have been investigated by Lisse et al [171], who found that a high abundance of macroscopic particles with β values of β < 10 −3 , corresponding to dust-particle sizes of 1 mm, are present in the trails. Moreover, cometary meteor showers exhibit particle sizes up to ∼1 cm [172]. As stated above, direct observational evidence of pebble substructures is not available.…”