1. Division of Geological and Planetary Sciences, California Institute of Technology, MS 170-25, Pasadena, California 91125, USA
2. Institute of Astronomy, Charles University, V Holeovickách 2, 180 00 Prague 8, Czech Republic
3. Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 400, Boulder, Colorado 80302, USA

Correspondence to: Kenneth A. Farley¹ Correspondence and requests for materials should be addressed to K.A.F. (Email: farley@gps.caltech.edu).

Abstract

Throughout the history of the Solar System, Earth has been bombarded by interplanetary dust particles (IDPs), which are asteroid and comet fragments of diameter 1–1,000 m. The IDP flux is believed to be in quasi-steady state: particles created by episodic main belt collisions or cometary fragmentation replace those removed by comminution, dynamical ejection, and planetary or solar impact. Because IDPs are rich in ³He, seafloor sediment ³He concentrations provide a unique means of probing the major events that have affected the IDP flux and its source bodies over geological timescales^{1, 2, 3, 4}. Here we report that collisional disruption of the >150-km-diameter asteroid that created the Veritas family 8.3 0.5 Myr ago⁵ also produced a transient increase in the flux of interplanetary dust-derived ³He. The increase began at 8.2 0.1 Myr ago, reached a maximum of 4 times pre-event levels, and dissipated over 1.5 Myr. The terrestrial IDP accretion rate was overwhelmingly dominated by Veritas family fragments during the late Miocene. No other event of this magnitude over the past 10⁸ yr has been deduced from main belt asteroid orbits. One remarkably similar event is present in the ³He record 35 Myr ago, but its origin by comet shower¹ or asteroid collision⁶ remains uncertain.

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