Title: The Origin of Chondritic Meteorites

Speaker: Frank Shu (UC Berkeley)

Abstract: Chondrites are the most primitive of meteorites and have
internal structures that are a perplexing mixture of rocks
that have experienced very high temperatures and rocks
that never underwent much heating.  In many chondrites,
spherical droplets of magnesium-iron silicates called
chondrules, of roughly millimeter size,
were once molten for perhaps an hour and
occupy more than 50\% of the volume of the meteorite.
We present a theory for the origin of such objects,
and the related calcium-aluminum-rich inclusions,
that represents a detailed development of physical ideas
first presented by George Herbig in his 1977 Russell Lecture.
This theory has the potential to change many of our
prevailing ideas concerning the first steps by which
planets are assembled from the solid material
existing in the nebular disks surrounding newly forming stars. 
\end