Allende. Presolar grains
As stars age, they spew out great quantities of dust grains into interstellar space. Early in our solar system's history, dust that formed around stars older than the Sun reached the solar nebula and mixed with chondrules, calcium-aluminum inclusions (CAIs) and dust particles from our solar system.
Today, small amounts of this stardust, known as presolar grains, can be found in some meteorites. The Allende meteorite contains many types of presolar grains, including tiny diamonds that consist of only about 1,000 carbon atoms. This vial contains about 60 quintillion (6 followed by 16 zeros) of these "nanodiamonds," isolated from a fragment of Allende similar in size to the 5.7-gram (0.013-pound) piece displayed here.
ALLENDE Presolar Grains
Prepared and donated by Roy Lewis, Senior Scientist, Enrico Fermi Institute, University of Chicago
Subtopic: Milky Way Galaxy
Keywords: Astrophysics, Cosmic dust, Chondrites (Meteorites), Interstellar matter, Astrogeology, Chondrules