Meteorites & Asteroids

An Upper Limit on the Interstellar Meteoroid Flux at Video Sizes from the Global Meteor Network

By Keith Cowing
Status Report
astro-ph.EP
March 27, 2025
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An Upper Limit on the Interstellar Meteoroid Flux at Video Sizes from the Global Meteor Network
The radiants in RA and Dec of the 472 fastest (vhel ≧ 44 km s−1 ) events along with the radiants of some known meteor showers and some relevant fiducial directions such as the Galactic Center. For the showers, the 10 most active annual IAU meteors showers that are seen by GMN (that is, that contain significant mm sized particles) and that have in-atmosphere speeds below 50 km/s. Directional values: the position of the Galactic Center (Reid & Brunthaler 2004); the Solar apex with respect to the Local Standard of Rest (LSR) (Jaschek & Valbousquet 1992); the Solar apex with respect to the Galactic frame (Solar Galactic Apex); and the interstellar dust (ISD) influx direction into the Solar System as reported by spacecraft Cassini, Ulysses, and Galileo, due to the motion of the Solar System through the Local Interstellar Cloud (LIC) (Sterken et al. 2012). No strong signature of the Galaxy or of meteor showers is seen. — astro-ph.EP

Material arriving at our solar system from the Galaxy may be detected at Earth in the form of meteors ablating in our atmosphere. Here we report on a search for interstellar meteors within the highest-quality events in the Global Meteor Network (GMN) database. No events were detected that were conclusively hyperbolic with respect to the Sun; however, our search was not exhaustive and examined only the top 57% of events, with a deeper examination planned for future work.

This study’s effective meteoroid mass limit is 6.6 +/- 0.8 x 10-5 kg (5 millimeter diameter at a density of 1000 kg m-3). Theoretical rates of interstellar meteors at these sizes range from 3 to 200 events globally per year.

The highest rates can already be largely excluded by this study, while at the lowest rates GMN would have to observe for 25 more years to be 50% confident of seeing at least one event. GMN is thus well positioned to provide substantial constraints on the interstellar population at these sizes over the coming years.

This study’s results are statistically compatible with a rate of interstellar meteors at the Earth at less than 1 per million meteoroid impacts at Earth at millimeter sizes, or a flux rate of less than 8 +/- 2 x 10-11 per sq. km per hour at the 95% confidence level.

Paul Wiegert, Vanessa Tran, Cole Gregg, Denis Vida, Peter Brown

Comments: 20 pages, 9 figures, accepted by the Astrophysical Journal
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2503.19042 [astro-ph.EP] (or arXiv:2503.19042v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2503.19042
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Submission history
From: Paul A. Wiegert
[v1] Mon, 24 Mar 2025 18:12:37 UTC (1,431 KB)
https://arxiv.org/abs/2503.19042
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