Observer’s Guide to Martian Apparitions 2012–2022
Early on in the season the extensive north polar hood begins to dissolve while the south polar cap starts its retreat. Emerging into the warmth of the Sun a once frosty Hellas clears and darkens. Orographic cloud may be visible over Apollinaris Mons and there is the possibility of dust clouds in the southern hemisphere. Mid-season the north polar cap is eventually exposed, with the possibility of the appearance of Rima Tenuis. In the last part of the season, the limb regions often appear bright; there is increasing cloud in the north and hazes may be seen in both the north and south.