It is clear that the chondritic meteorites - those having essentially solar composition - carry unique information about the origin and early history of the solar system and the materials from which the planets formed. Yet it is a highly complex record that centuries of work and highly sophisticated modern techniques have not been able to decipher. Even the most fundamental issues, the origin of the chondrite classes and the origin of the chondrules that distinguish the meteorites from other materials, are still disputed.
Dr. Sears will argue that recent data from spacecraft on the nature of asteroid surfaces, advances in determining the chronology meteorites and their components, experiments flown on NASA's microgravity facility (the vomit comet), and the lunar samples returned from the Fra Mauro region of the Moon, make it clear that chondrules are impact melt spherules and the classes are caused by metal-silicate fractionation on asteroidal surfaces. In other words, the chondritic meteorites owe their major properties to asteroidal processes and that we must see through these to understand the information they carry about the early solar system and beyond.