부산대학교 도서관

One of the most fundamental questions in planetary science is, How did the solar system form? In this special issue, astronomical observations and theories constraining circumstellar disks, their lifetimes, and the formation of planetary to subplanetary objects are reviewed. At present, it is difficult to observe what is happening within disks and to determine if another disk environment is comparable to the early solar system disk environment (called the protoplanetary disk). Fortunately, we have chondritic meteorites, which provide a record of the processes that operated and materials present within the protoplanetary disk.
Chondrites are 4.5672 ± 0.6 billion-year-old (1) rocks derived from the aggregation of dust and other rocks within the protoplanetary disk (Fig. 1). Arguably the oldest components of chondrites are [...]