NASA Spots Another Hole in the Sun
A few days ago, NASA captured images of a massive hole in the Sun’s surface. This anomaly is known as a coronal hole. Coronal holes spew out materials from within the Sun into the solar wind at a rapid pace. This latest coronal hole is square in shape and appears in the southern region on the massive sphere.
It’s not the first coronal hole nor will it be the last to be found over the past year. Back in July of 2013, footage of another hole was caught as described here. This particular hole was found by the Solar Dynamics Observatory (SDO) at the beginning of May.
Brief footage of the anomaly can be seen below.
Coronal holes are not overly uncommon, with at least a few of them occurring each year. But the Sun does go through cycles of roughly 11 years, and this year is the 11th, most active of those years. That means there should be quite a lot of holes to view as we wait for things to calm down on the solar surface again. But the question remains: what, exactly, causes them?
We know what they are–darker, colder areas with a lower-density plasma which spew material out into the solar wind. We know that the frequency and location of these anomalies differ during solar maximum, when they are found all over the Sun, and at solar minimum, when the holes are usually found closer to the poles.
The corona, where these particular holes occur, is part of the Sun’s atmosphere, along with the photosphere and the chromosphere. The corona is considered a sort of cover for the transitional region beneath. Solar material tends to build up in the transitional region and needs a way to get out. One of the more important functions in the transitional region is helium ionization. Helium ionization produces the energy the sun radiates, and as it heats up, these hotter helium atoms help form the corona itself.
The cooler material below the corona contains only partially ionized helium, but when it heats up and rises to the top, it creates a temperature catastrophe, sort of like how boiling water produces steam. The holes are a way for that “steam” to escape. Then they spew solar energies at a super-rapid speed out into the solar wind, and those sometimes-harmful particles continue out into space, occasionally causing trouble. Scientists assure us, however, that our planet has little to worry about where this coronal hole is concerned as its placement in the southern region makes its wind much less likely to have any harmful effect on our world.