Erik Asphaug is the Ronald Greeley Chair of Planetary Geology at the School of Earth and Space Exploration at Arizona State University in Tempe, Arizona.
How Cosmic Collisions Have Shaped Our Solar System
Some of our solar system’s landmarks can trace their origins to massive impacts.
Scientists in the Dark Over Birth of the Moon
Two new studies present very different ideas about how the Moon was formed—a riddle that one scientist says may never be solved.