Polar regions offer good Moon/Mars analogs because they provide extreme environmental conditions along with relevant geologic features and stressed microbial habitats as may exist on the Moon or Mars. Polar sites are also remote and isolated, with little or no local infrastructure and resources. Devon Island in the Canadian Arctic is set in a polar desert, with cold climate, a frozen subsurface, and a high ultraviolet flux during the 24-hour summer sunlight. Haughton Crater is relatively large and exceptionally well preserved, and contains fluvial, glacial, and periglacial geological features along with microbial niche habitats.
Shackleton Crater at the South Pole of the Moon is 19 km in diameter and its lunar regolith might contain water ice in surrounding permanently shadowed zones. It is a prime candidate site for human exploration, and one of the prime targets of the Ames Lunar Crater Observation and Sensing Satellite (LCROSS) mission in 2009.
Haughton Crater, also approximately 20 km in size, is by far the best-preserved impact structure of its class on Earth and is located in a rocky desert rich in subsurface water ice. Haughton may be the best overall scientific and operational analog for lunar craters such as Shackleton.