Almost all the evidence about the nascent solar system has been erased by processes accompanying the formation of the Sun and the bodies that formed out of the circumsolar disk about 4.6 billion years ago.  But some meteorites and the tiny dust grains contained within them have anomalous compositions that can only be understood by invoking a history going back to the giant molecular cloud progenitor of the solar system, and to the stars that ejected the material that formed the cloud.  Rick Carlson explains what the anomalies are and how we can use them to learn about what might have being going on in the solar nebular as the solar system was forming. Rick Carlson is an isotope geochemist who measures such anomalies and uses them as clues to the birth of the solar system.  He is Director of the Earth and Planets Lab at Carnegie Science in Washington DC. Go to geologybites.com for podcast illustrations and to learn more about Geology Bites.