Asteroids are now geologic entities, and the astronomers to whose dominion they belonged since 1801 are in search of a new intuition. In turn, the geologists who have begun to study rocks in space are learning the vernacular of telescopes, spacecraft, and celestial mechanics. The marriage of disciplines, made in heaven, has resulted in a complex and diverse new science appropriate to the multifarious asteroids themselves, a science which evolves discovery by discovery, sometimes accompanied by the wholesale overturn of established thought.
This turmoil may surprise those who are new to the field, yet asteroids represent a geophysical frontier of considerable importance. They are the building blocks of planets, and are some of the most dangerous objects in the solar system. I will introduce the subtlety of asteroids through an exploration of one central theme, the paradox of strength versus gravity, this being what defines them. Guided by spacecraft and groundbased imaging and geophysical modeling, one idea has begun to resonate: Instead of competing for dominance, strength and gravity gently collaborate to produce some of the richest structures in nature