Some lectures are one of a kind. Others are given over and over again, sometimes under different titles (in this list, only the latest title is indicated). The content of a talk can vary quite considerably, depending on the audience. Some talks tend to "evolve" as they are repeatedly given. Listed below are some favored topics. The "Planet Earth Series" of talks deal with earthly topics only. Click on the title and a list of venues will appear. (* indicates that the talk has been given 5 or more times, ** 10 or more times and *** 20 or more times.)
"DOOMSDAY ASTEROIDS AND COMETS" **
"GEOLOGY: THE EARTH AS A PLANET"
"COLLISIONS OF COMETS AND PLANETS" **
"A FIELD TRIP THROUGH THE SOLAR SYSTEM"
"METEORITES AND OTHER SPACE DEBRIS"
"SALT WEATHERING ON EARTH AND MARS"
"IMPACT STRUCTURES ON THE TERRESTRIAL PLANETS"
"BASALTIC FLOODING OF PLANETARY LANDSCAPES" **
"EVOLUTION OF THE GALILEAN SATELLITES OF JUPITER"
"EXPLORING THE MARTIAN DESERT" **
"THE GEOLOGICAL CASE FOR LIFE ON MARS" ***"MARS: WHERE DID ALL THE WATER GO?" **
"EXPLORING THE LUNAR LANDSCAPE"*
"IS THERE LIFE ELSEWHERE IN THE SOLAR SYSTEM?"*
"VENUS: EXPLORING THE INFERNO" **"ATMOSPHERES AND OCEANS OF THE TERRESTRIAL PLANETS" **
"MERCURY: THE FORGOTTEN PLANET"**"THE
CRYOGENIC WORLD OF TRITON"