What’s up with the square hole in the Sun?
A NASA spacecraft has made a surprising find on the surface of the sun: a square-shaped “hole” in the star’s outer atmosphere.
The dark square on the sun, known as a “coronal hole,” is an area where the solar wind is streaming out of the sun at superfast speeds.
In 2013, NASA spotted a large coronal hole near the sun’s north pole and noted, “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.”
The coronal hole, almost square in its shape, is one of the most noticeable features on the Sun. The coronal hole appears dark in the NASA view because there is less material emitting light in the ultraviolet range of the spectrum used to make the video, according to a NASA video description.
The hole was captured on video taken May 5 to 7, 2014.
“Inside the coronal hole you can see bright loops where the hot plasma outlines little pieces of the solar magnetic field sticking above the surface.”
Solar Dynamics Observatory stated:
Because it is positioned so far south on the Sun, there is less chance that the solar wind stream will impact us here on Earth.
NASA’s sun-watching Solar Dynamics Observatory is just one of a fleet of spacecraft keeping a close watch on the weather on Earth’s parent star. In 2013, the sun experienced its peak activity of its 11-year solar weather cycle.
One of the big questions: What happens to Earth when the sun dies?
Source | SDO