Sep 30, 2021

Nicolle Zellner, Albion College

"Reassessing Impact Bombardment in the Earth-Moon System"

The characteristics of the impact flux in the Earth-Moon system, especially during the first 700 million to 1 billion years of Earth’s history, have been debated by scientists for decades. In particular, after analyses of lunar impact samples, uncertainties around its profile have persisted: did the impact flux taper off after final planetary accretion and sweep-up of debris or was there a short-lived influx of impactors at ~3.9 billion years ago? As Earth’s nearest neighbor, the Moon’s impact flux is applied to Earth, as well as to other planetary bodies in the inner solar system. Advances in acquiring, analyzing, and interpreting lunar (and other) data are allowing us to refine our interpretations of the nature and extent of the impact flux, from shortly after the solar system formed to the present. These data are allowing us to better understand how impacts may have influenced (or not) Earth’s biological and geological activities and permit us to also speculate on how it may have affected Mars.

We strongly encourage you to attend the colloquium in person. If that is
impossible, it is available over zoom at the following link:



Event Details

Sep 30, 2021


4421 Sterling Hall, Coffee and tea 3:30 pm, Talk starts at 3:45 pm

Speaker Host:
Amy Barger

UW-Madison Astronomy Home