A foreboding image was recently received at NASA's Solar Dynamics Observatory, depicting a giant, gaping dark hole in our sun that was spewing intense solar winds out into space. It's an event that sounds more catastrophic than it is, but that doesn't mean it's not without consequence.
The image above portrays the coronal hole (displayed as the large dark region), which is not, strictly speaking, a "hole." Coronal holes, like the infamous hole in the ozone layer here on Earth, don't reach all the way through the atmosphere. Rather, they are regions that are cooler and less dense than the surrounding plasma, caused by quirks in the sun's magnetic field. Whether a hole in the strictest sense or not, these events cause weaknesses in the atmosphere that can let particles pour out much faster than under normal conditions, reports Livescience.
Severe solar winds gushing out of holes like this can seriously disrupt our way of life on Earth, potentially jeopardizing satellites and power grids. Coronal holes are not uncommon events, but they don't often get as large as this one was. In fact, scientists suspect that this hole was the cause of some extreme auroras that were recorded reaching as far south as Nebraska. Luckily, however, our power grids survived the blast.
Interestingly, coronal holes come and go with varying frequency in concert with the sun's 11-year cycle. The most intense periods are during the cycle's minimum phase, which we won't be entering until 2019. During this time, holes can grow larger and last longer, some lasting for several of the sun's rotations (which take 27 days on average).
This hole only lasted for a couple of days, which is probably a good thing given the size of it.
The event is a reminder as to the importance of DSCOVR (Deep Space Climate Observatory), a satellite launched in 2015 that sits 1,500,000 kilometers from Earth, and which serves as an early warning signal for intense solar storms headed our way.