NASA's Solar Dynamics Observatory (SDO) captured an immense filament of solar material snaking across the surface of the sun, giving it the appearance of a large sad face. The 533,000 mile long filament (longer than 67 Earths lined up in a row) appears as a dark line in the SDO image which indicates an area of cool dense gas hovering in the sun's atmosphere. Filaments can last for days before disappearing or erupting into space as coronal mass ejections. More at Huffington Post.