Astronomy Picture of the Day . Jupiter's Ring Halo . ... Hale-Bopp from Indian Cove . ... M101: The Pinwheel Galaxy . ... Why do many galaxies appear as spirals? ... A Rusty Sunset on Mars . ... The unusual color is partly due to rust: oxidized iron from Martian dust circulating in the Martian atmosphere. ... The collision of this fast moving wall of gas with.. ... A Martian Sunset . ... The above pictures taken by Mars Pathfinder highlight how clouds vary during the end of a Martian day. ...