image: Calcium-aluminum-rich inclusions (CAIs) formed by condensation of volatilized dust in the hot, innermost region of the protoplanetary disk whereas chondrules formed further from the sun by accretion and melting of dust particles. Contrary to accepted models, this study shows that chondrules started forming contemporaneously with CAIs at 4567.30±0.16 My and continued to form for another 3 million years. This time scale is comparable to disk lifetimes inferred from astronomical observations and astrophysical predictions, suggesting that CAI and chondrule formation reflects a process intrinsically linked to the secular evolution of accretionary disks. This image relates to a paper that appeared in the Nov. 2, 2012, issue of Science, published by AAAS. The paper, by James Connelly at the University of Copenhagen in Copenhagen, Denmark and colleagues was titled, "The Absolute Chronology and Thermal Processing of Solids in the Solar Protoplanetary Disk." view more
Credit: Background image courtesy of NASA/JPL-Caltech/T. Pyle (SSC); Chondrule images courtesy of Mia Olsen.