Johannes Schöner was a renowned and respected German polymath. It is best to refer to him using the usual 16th-century Latin term "mathematicus", as the areas of study to which he devoted his life were very different from those now considered to be the domain of the mathematician. He was a priest, astronomer, astrologer, geographer, cosmographer, cartographer, mathematician, globe and scientific instrument maker and editor and publisher of scientific tests. In his own time he enjoyed a European wide reputation as an innovative and influential globe maker and cosmographer and as one of the continents leading and most authoritative astrologers. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Mars large craters are named after deceased scientists, writers and others who have contributed to the lore of Mars. Small creaters (less than 60km) are named after small towns and villages.