Microscopic analyses of chondrites, the oldest rocks in the solar system, are filling in details about the formation of our solar system.
http://www.scientificamerican.com/article.cfm?id=what-oldest-meteorites-say-about-early-solar-system
http://www.scientificamerican.com/article.cfm?id=what-oldest-meteorites-say-about-early-solar-system