Rupes Kelvin is an escarpment near Promontorium Kelvin on the near side of the Moon, at 27°18′S 33°06′W / 27.3°S 33.1°W. It is 86 km long. It takes its name from Promontorium Kelvin,[1] which was named after the Irish scientist, physicist and engineer William Thomson, 1st Baron Kelvin.[2]