Xenoarchaeology is a form of archaeology concerned with the physical remains of past (but not necessarily extinct) alien cultures. The UNSC is known to have practiced Xenoarchaeology on various worlds occupied by the Forerunners in the past, such as Onyx. Known practitioners of xenoarchaeology include Dr. William Arthur Iqbal, Esko Korpijaakko, and Laszlo Sorvad. After the Human-Covenant war, many researchers from the universities of Edinburgh and Calcutta were hired by the Office of Naval Intelligence to investigate Forerunner relics.