A substantial coronal hole rotated across the face of the sun this past week and is again streaming solar wind towards Earth (Jan. 30 - Feb. 2, 2017). This same coronal hole was facing Earth about a month ago and has rotated into a similar position again (see our Gallery entry for this here: http://sdo.gsfc.nasa.gov/gallery/main/item/769. Coronal holes are areas of open magnetic field from which solar wind particles stream into space. In this wavelength of extreme ultraviolet light it appears as a dark area near the center and lower portion of the sun.
SDO is managed by NASA's Goddard Space Flight Center, Greenbelt, Maryland, for NASA's Science Mission Directorate, Washington. Its Atmosphere Imaging Assembly was built by the Lockheed Martin Solar Astrophysics Laboratory (LMSAL), Palo Alto, California.