Planet Four is a citizen science project designed to help planetary scientists identify and measure features on the surface of Mars
All of the images on this site depict the southern polar region, an area of Mars about which little is known. The images on this site come from the HiRISE (High Resolution Imaging Science Experiment) camera on board the Mars Reconnaissance Orbiter. HiRISE can image Mars with resolutions of 0.3 m/pixel (about 1 foot), resolving objects below a meter across.
Planetary scientists believe that these features indicate the Martian wind direction and speed. By tracking ‘fans’ and ‘blotches’ over the course of several Martian years to see how they form, evolve, disappear and reform, we can better understand Mars’ climate.