LUNAR ACCRETION FROM AN IMPACT-GENERATED DISK

Although the mechanism by which the Moon was formed is currently unkno wn, several lines of evidence point to its accretion from a circumterr estrial disk of debris generated by a giant impact on the Earth. Theor etical simulations show that a single large moon can be produced from such a disk in less than a year, and establish a direct relationship b etween the size of the accreted moon and the initial configuration of the debris disk.