The term 'Martian Feature' refers to features found on the planet Mars. The crossword solutions for this term are CANAL (5 letters), CRATER (6 letters), ICECAP (6 letters), and POLARCAP (8 letters). A CANAL is a man-made waterway, while a CRATER is a large, bowl-shaped depression in the surface of a planet or moon. An icecap is a large area of permanent ice and snow, while a polar cap is an ice cap located at one of the poles of a planet. All of these features can be found on the surface of Mars.