Some recent images of the Sun, captured by NASA’s Solar Dynamics Observatory (SDO), showed a dark line running across its surface. The images captured on February 10, 2015, show a filament of solar material hovering above our star’s surface. The hotter material was shown as light and colder material as dark. Thus the line was, in actual fact, an enormous swatch of cooler material hovering in the Sun’s atmosphere - the corona.
NASA researchers said that solar filament would be more than 533,000 miles in length, in case it was stretched out. That figure is equivalent to the distance created by more than 67 Earths lined up in a row.