Penn State University astronomer Darren Williams presents “The Origin of the Moon and Other Planetary Satellites” Wednesday, May 26 at 8 p.m. at Lawrence University’s Thomas Steitz Science Hall Room 102. The address is free and open to the public.

The program will explore the leading theory on the formation of the Earth’s moon — a cosmic chance collision between a Mars–sized protoplanet and the infant Earth.

Darren-Williams_web
Darren Williams

Williams also will discuss other bodies in the solar system that were formed from “rings of debris” and through gravity capture. According to Williams, examples of planetary satellites formed through gravity capture suggest moons the size of Earth could be commonplace around nearby stars in our galaxy.

A specialist on the origin and evolution of planet-satellite systems, Williams is an associate professor of physics and astronomy at Penn State Erie, The Behrend College.

His appearance is supported by the Harlow Shapley Visiting Lectureship Program of the American Astronomical Society, which brings professional astronomers to college campuses for two-day visits. The program is named for American astronomer and educator Harlow Shapley, who uncovered the dimensions of the Milky Way galaxy and Earth’s place in it.