AST 301: Collisions in the Solar System

Spring 2021

F.M. Walter


This course will meet online, via Zoom


Even if the probability of a technological civilization evolving is very small, the sheer number of planets in the Galaxy suggests that we are not alone. But the "Great Silence" has been interpreted to mean that there is some "Great Filter" that smothers the development of technologically-advanced civilizations.

In AST301 we will consider the various factors that make the Earth a risky to live. Every year about 20,000 tons of extraterrestrial matter collide with the Earth, mostly burning up harmlessly in the upper atmosphere. But occasionally some larger bodies get through, with potentially disastrous consequences. Geology and Paleontology inform us of frequent mass extinctions, some triggered by collisions, and others triggered internally. Together they testify to the fragile hold of multicellular life on the surface of our planet. We will discuss how these events, interactions between Sun and the Earth, explosive events elsewhere in the Galaxy, and now our own technological prowess, have played a significant role in the evolution of the Solar System, of the Earth, and of life on our planet.

Our ultimate goal is to understand the risks of living on a fragile planet in an indifferent universe.


These pages maintained by
Prof. Frederick M. Walter
Astronomy Program
Dept. of Physics and Astronomy
State University of New York
Stony Brook, NY 11794-3800
631-632-8232
email: frederick.walter at stonybrook.edu (replace the "at" with "@")

These pages copyright 2020 by Frederick M Walter