Abstract: In this paper, two scanning paradigms are presented and compared that may be used for robotic scanning of a harsh environment such as a celestial body or earth poles. The first paradigm, tight scanning, includes three algorithms which may be used to find small objects or gasses confined to small regions such as the methane gas given off by bacteria in buried hot springs in the Canadian arctic. The second paradigm, relaxed scanning, includes four algorithms which may be used to find large objects such as large ice deposits that may be buried just below the surface of Mars. The algorithms are compared against their peer algorithms by their quality of performances. Such performance quality is determined by the ratio of scanned area to the traveled distance by the two robots.