Summer Has Come to the Martian South Pole
Like the Earth, Mars is tilted on its axis which produces seasons: Spring, Summer, Fall, and Winter just like the Earth has. It’s during the Spring and early Summer in the South Pole (and in dunes in the Northern hemisphere), that the fans and blotches that you map in the images in the classification interface appear.
Yesterday marked the official start of Summer on the South Pole of Mars and the shortest day of the year in the Martian Southern Hemisphere. The carbon dioxide ice sheet that once covered places like Inca City, Manhattan, and Ithaca should be gone or nearly gone at this point. The dark fans and blotches imaged by HiRISE in August-November of last year (and you can now map those images from Inca City in that sequence on the site) have now disappeared back into the regolith. The days will begin to get shorter and the HiRISE seasonal monitoring campaign will eventually switch to the Northern hemisphere. But the geysers and fans will be back in the South and so will the HiRISE images starting around mid 2016.
In the meantime, we’ve got plenty of images of fans and blotches needing your help to map at http://www.planetfour.org