NASA Finds Square Shaped Hole in the Sun
Posted on May 12, 2014
NASA has found a square shaped hole in the Sun. The coronal hole was captured by the Solar Dynamics Observatory. NASA says a coronal hole is "an area where high-speed solar wind streams into space." Coronal holes were first found in x-ray images in the 1960s. A large coronal hole was found near the Sun's north pole last summer, see here.
NASA says the newly discovered coronal hole appears dark in ultraviolet light because there is less material to emit in these wavelengths. The bright loops seen in the coronal hole are hot plasma outlining pieces of the solar magnetic field sticking above the surface. Here is some video of the coronal hole: