Today's Sun - look at this beautiful coronal hole (the dark area). Coronal holes are regions where the sun's corona is dark. These features were discovered when X-ray telescopes were first flown above the Earth's atmosphere to reveal the structure of the corona across the solar disc. Coronal holes are associated with 'open' magnetic field lines and are often found at the sun’s poles. The high-spee...d solar wind is known to originate in coronal holes. The solar wind escaping from this hole will reach Earth around August 18-19, 2012.
And also today at 1930 UTC (3:30 pm ET, 12:30 pm PT) SDO will perform a Delta-H maneuver. This is designed to keep the fine-guidance system within limits by using a series of short burns on the thrusters.
Thursday we will do two more maneuvers. The EVE Field-of-View maneuver will start at 1315 UTC (9:15 am ET) and the HMI/AIA Flatfield at 1630 UTC (12:30 pm ET).
Before, during, and after a maneuver SDO data may be unavailable.
Credit: NASA SDO