curprev17:1217:12, 12 February 2021 SnailsAttacktalkcontribs 9,781 bytes+1,779 Added a "Geology" and "Surface material" section based on the "RECONSTRUCTING HELENE’S SURFACE HISTORY – PLASTICS AND SNOW" paper. (https://www.hou.usra.edu/meetings/lpsc2015/pdf/2400.pdf) Linked on the page as source #2.undoTag: Visual edit