Massive coronal hole spotted near sun's north pole
Monday, July 22, 2013, 2:42 -
Here comes the sun -- and it's all right.
ESA and NASA'a solar observatory captured a massive coronal hole near the sun's north pole last week. The large dark spot in the image above represents a low-density region of the sun's coronoa. It has a lower temperature than the fiery ball that surrounds it -- but rest assured it's still very hot.
Here's more from NASA:
"Coronal holes are a typical feature on the sun, though they appear at different places and with more frequency at different times of the sun’s activity cycle. The activity cycle is currently ramping up toward what is known as solar maximum, currently predicted for late 2013. During this portion of the cycle, the number of coronal holes decreases. During solar max, the magnetic fields on the sun reverse and new coronal holes appear near the poles with the opposite magnetic alignment. The coronal holes then increase in size and number, extending further from the poles as the sun moves toward solar minimum again ...
The holes are important to our understanding of space weather, as they are the source of a high-speed wind of solar particles that streams off the sun some three times faster than the slower wind elsewhere. While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere."
While this coronal hole is impressive, it isn't unique. Click on the video below to see the spectacular coronal hole captured by NASA between May 28 and 31, 2013.