CURRENT Research and other stuff:


Arizona State University

This Fall I joined the School of Earth and Space Exploration (SESE) at ASU, in Tempe, Arizona.  The Ronald Greeley Chair honors a great Arizona scientist, and a friend and mentor. I hope to continue his blend of empirical and theoretical research, advancing into areas related to microgravity geology on asteroids, comets and small moons, and deployable spacecraft.

University of California, Santa Cruz

Through 2012 I was a professor of Earth & Planetary Sciences at UCSC, helping to create their planetary sciences program. Santa Cruz is a spectacular home to some of the world’s most creative students and faculty, and is not easy to leave! 



Phobos, the innermost moon of Mars, imaged in 1989 by the Russian Фобос-2 mission.  Color processed by Ted Stryk.  I never fail to be moved by this image -- a charcoal-black world the size of Mt. Shasta, possibly a captured primitive asteroid, in front of the dusty plains of Mars.  Is it a stepping stone for human exploration beyond Earth?  Is it doomed?

I study planetary physics at large & small scales: the giant impacts that formed the Earth and Moon and other planets, and the microgravity geology of comets and asteroids.