Melt-water formed dark streaks on slopes of Haughton crater as possible Mars analogues

摘要

Haughton crater in the Canadian Arctic has been extensively used as a Mars (and lunar) analogue over the past 20 years. Here we report on small scale, dark, semi-seasonal slope streaks formed by melt water flowing down the crater walls that we observed during the Mars Society-sponsored M160 expedition to the F-MARS facility on the NW rim of the crater. The streaks are formed by biofilms colonizing snow melt flowing from semi-permanent snow patches in Haughton crater on Devon Island and elsewhere in the Canadian Arctic. These features superficially resemble the dark slope streaks and recurring slope lineae (RSL) observed on Mars and may serve as analogues for wet models for their formation and a contrast with dry formation models. Their significance to astrobiology and planetary science is three-fold: (1) as examples of dark recurring streaks known to be associated with water they provide a benchmark to compare with Martian slope streaks and RSL. (2) The melt streaks may have potential as astrobiological analogues for wet models of slope streaks and RSL. (3) They are natural laboratories to study planetary protection issues associated with robotic and astronaut exploration of potential water-related slope features on Mars.