American; Palmer's ship to explore Antarctic coast, 1820-21.
Hero Rupes is an escarpment on Mercury more than 300 kilometers long located in the southern hemisphere of Mercury. Discovered by the Mariner 10 spacecraft in 1974, it was formed by a thrust fault, thought to have occurred due to the shrinkage of the planet's core as it cooled over time. (wikipedia entry)
A rupes is a scarp. On Mercury they are named after ships of discovery or scientific expeditions.
Image Source. Marker locations are approximate and may not always appear to align with image on map.