Mariko is an impact crater on Venus. In 1997 it was named for a common female Japanese first name, in accordance with planetary nomenclature rules for Venusian craters under 20km in diameter. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Venus they are named after deceased women who have made outstanding or fundamental contributions to their field (if over 20 km). If smaller common female first names are used.
Image Source. Marker locations are approximate and may not always appear to align with image on map.