Geochemical evidence for a comet shower in the late Eocene

Science
By: , and 

Links

Abstract

Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began ~1 My before and ended ~1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters ~36 million years ago. The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced. These observations provide evidence for a comet shower triggered by an impulsive perturbation of the Oort cloud.
Publication type Article
Publication Subtype Journal Article
Title Geochemical evidence for a comet shower in the late Eocene
Series title Science
DOI 10.1126/science.280.5367.1250
Volume 280
Issue 5367
Year Published 1998
Language English
Publisher American Association for the Advancement of Science
Description 4 p.
First page 1250
Last page 1253
Google Analytic Metrics Metrics page
Additional publication details