Roberto Gorelli points our attention at a recently published meteor related paper:

The Dynamical Origin of Millimetre-Sized Sporadic Meteoroids

This article has been submitted for publication by Tam Doa, Peter Brown and Petr Pokorný.

Abstract: Determining the relative contributions of cometary and asteroidal sources to the sporadic meteoroid population remains a longstanding challenge, particularly because commonly used orbit-based classification criteria have not been rigorously validated for meteoroids. We evaluate the efficacy of several established orbit-based criteria for meteoroid classification. These include the Whipple (1954) 𝐾-criterion, Kresák (1967) 𝑃 𝑒-criterion, the Tisserand (1890) invariant with respect to Jupiter (T𝐽), and a recent classification based on aphelion distance proposed by Borovička et al. (2022). Our validations suggest that 𝐾 and 𝑃 𝑒 are most reliable at recovering whether a meteoroid was released from a cometary or asteroidal parent. We applied these criteria to a suite of 386 observed millimetre-sized meteoroids to try to constrain their original source populations. Our analysis used the observed orbit co-variances to backward integrate a suite of clones for each meteoroid to statistically evaluate their dynamical origin.
We find that if meteoroids are released in the last ∼150 − 200 kyr, there is a dividing velocity of below 17 km/s where meteoroids in the millimetre to centimetre size range impacting Earth are predominantly asteroidal in origin, independent of the orbital criteria used. Above 17 km/s, the fraction of dynamically cometary meteoroids increases, although a definitively cometary dominated population does not arise until velocities of 27 km/s or higher. For ages older than 200 kyr, lower velocity meteoroids at Earth in the mm-sized range may be a mix of either cometary or asteroidal.
Meteoroids from different source populations experience distinct perihelion histories. Thermal processing provides an additional modifier of physical properties making origin determinations from dynamical history or directly observed material properties challenging. We examined the role of past thermal processing in the apparent physical strength of meteoroids. The vast majority of meteoroids in our dataset which experience low perihelion are cometary in origin and exhibit higher 𝑘𝑐. This may reflect either that these meteoroids are young or that thermal cycling (Čapek and Vokrouhlický, 2012) enhances fragmentation susceptibility. At the same time extreme thermal processing may preferentially remove the highest-𝑘𝑐 (weakest) meteoroid population on cometary orbits, producing a survivor bias toward dynamically asteroidal meteoroids. If meteoroid ages are longer than 200 kyr, higher-𝑘𝑐 populations may be dominated by cometary material that evolved onto asteroidal orbits, supporting the common assumption of distinct intrinsic compositional differences between (weak) cometary and (stronger) asteroidal meteoroids.

You can download this paper for free: https://arxiv.org/pdf/2606.27452 (35 pages).

 

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