Incidence of low-density meteoroids of the Polonnaruwa type

TL;DR

This paper discusses the potential daily influx of low-density, cometary-origin micrometeoroids into Earth, highlighting the unnoticed Polonnaruwa-type meteorites that could be remnants of larger meteoroids surviving atmospheric entry.

Contribution

It introduces the concept of Polonnaruwa-type meteorites as a significant, overlooked class of meteorites originating from low-density micrometeoroids.

Findings

At least 5 tonnes of micrometeorites of cometary origin enter Earth daily.

Approximately 10% of these micrometeoroids are around 1 meter in size.

Polonnaruwa-type meteorites may be more common than previously recognized.

Abstract

The ingress of micrometeorites of cometary origin with densities below ~ 1 g cm-3 into the Earth could average at least 5 tonne per day. Although much of this is burnt upon entry through the atmosphere as meteors, a non-trivial fraction (~10%) which have sizes of ~ 1 m could end up in the form of Polonnaruwa-type meteorites that have mostly gone unnoticed.