Welcome back!

Last time, we discussed the parts of the Sun, its layers, and its characteristics. We discussed what the virtues of the Sun are, and what enables it to sustain life here on Earth. But there was one major part of the Sun that we left untouched: solar weather.

You see, there is a major subfield within heliophysics that focuses primarily on the various meteorological activities that occur on and around the Sun. Now, of course, there is a reason that we devote a field of study to this topic: it pertains considerably to our life here on Earth.

The scale, grandeur, and overall destructiveness that the storms on the Sun can cause life-changing events here on Earth. As a result, scientists have to continuously monitor the activity around it. Much like a toddler eating oatmeal, it would be in our best interest to know when a projectile of porridge–or plasma–is hurled in our direction.

So, without further ado, let us discuss the various features that our star offers us!

The Sun, being a burning ball of ionized gas floating in space, has considerable activity, but only during certain times. The Sun follows eleven-year cycles of activity and inactivity, either being completely dormant or spewing great tongues of plasma and huge doses of radiation. Much like the example with the toddler, they will not be able to hurl oatmeal if they are asleep.

We are currently in what is called a solar minimum. Scientists, however, are worried, as this minimum has lasted for a record long time.

 But why is this a cause of worry? 

Essentially, the longer that the Sun goes without experiencing a maximum, the more energy is being pent up in the Sun, meaning that when the Sun does maximize, the resulting burst of energy will be on never-before-seen proportions. It’s much like stretching a rubber band; the further you go, the more it will hurt when it snaps back.

But what are the signs of solar activity, and what happens when the Sun bursts out with such intensity?

Before we discuss the impacts that solar activity can have on Earth-bound life, we must discuss the types of solar activity. The most commonly known signs of solar activity include sunspots, solar flares, solar wind, and prominences. Each of them have their own novelties, and their own signals. So, let’s get into them!

Sunspots are, perhaps, the most unassuming of the above-listed signs of solar activity. They are simply areas where the Sun’s magnetic field punches a hole through the above layers, causing a dark spot to appear that has temperatures cooler than the surrounding area. Here is an example of a sunspot:

 Image result for sunspot

 Credit: National Weather Service

The reason that sunspots are so important is that they played a major role in the world’s rejection of theological astronomy. Galileo, by conducting detailed studies into the Sun’s surface with a telescope, noticed dark patches that he colored on his diagrams. He used these blemishes as proof that the Sun was not, indeed, perfect, as the Church had been preaching for so long.

This idea became revolutionary as people began to discredit more and more of the Church’s scientific teachings. Galileo’s further discoveries of craters on the moon caused this idea to be exemplified further, and caused more distance from the teachings of the Church. Unfortunately for Galileo, the Church proceeded to place him under house arrest for his teachings of heresy, and his casual, impertinent viewing of the Sun without protection led to early-onset blindness and death. Quite anticlimactic for someone who contributed so much to astronomy.

However, sunspots are further important because they can offer signals that the Sun is approaching its maximum. At a time where a maximum is necessary to prevent further damage in the future, they would be highly desired by scientists.

Next on our list: solar flares. These are, essentially, spots on the Sun with dramatic increases in temperature, that also release a potent cocktail of ions, electrons, and photons at immense speeds from the Sun. These events are very closely monitored by space meteorologists and have the power to wreak tremendous havoc on the situation on Earth.

 Image result for solar flareCredit: The Conversation

To discuss what damage that solar flares do, we must first discuss solar wind. Solar wind is, essentially, a constant stream of particles departing from the corona and traveling throughout the solar system.

Solar flares essentially inject this constant stream of solar wind with higher-energy particles and radiation. If the flare is small, it would simply interact with the Earth’s ionosphere and provide a light-show in the form of aurora. However, flares are sometimes accompanied by Coronal Mass Ejections–which, as in the name, are huge outbursts of the Sun’s corona–causing satellites and power grids to be disabled, the Earth to be incapacitated, and aurora to be seen as far south as Cuba.

An example of the dreadful effects that a geomagnetic storm of that magnitude can have was demonstrated in 1859. An especially powerful solar storm caused tremendous destruction to the newly established telegraph cables that traversed the entirety of the United States. Telegraph operators were electrocuted, power grids were shut down, and gold miners in the Rockies were woken up by what they thought was the Sun rising–but what was actually just aurora.

Now, if an event of that magnitude occurred today, the consequences would be considerably more dire. Modern estimates claim that a solar storm as powerful as the one that struck in 1859 would cause a tremendous $3.6 trillion in damage. Indeed, communication systems would be disrupted, satellites would be fried, and the power grid would be devastated; our entire way of life would collapse.

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Perhaps most scarily, a similar solar storm occurred in 2012. However, it missed the Earth by an exceedingly slim margin of 9 days.

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The last solar activities that I would like to discuss are prominences. They are, essentially, great arches that start from the surface of the Sun, travel millions of kilometers into space, and curve back onto the surface again.

Image result for solar prominence

Credit: NASA

 

These are typically less dangerous, but more spectacular than any of the other signs of solar weather. Great arches of fire show up beautifully on pictures, and are often the most prominent signs of solar weather. 

However, if a prominence breaks, it can take the form of a dangerous coronal mass ejection, as we discussed in the solar flare section. As a result, scientists take special care to make sure that the projections do not turn into anything more serious.

Solar activity can be beautiful, but dangerous in equal measures. Perhaps the most dangerous aspect about such activity is its scale; most flares and prominences range from dozens to hundreds of times the size of the Earth. It gives an example of the tremendous scale of the universe, and how massive the space around us really is.

 Image result for size of sunspot vs earth

Credit: Universe Today

But, on the other hand, it can provide us an excellent view of what stars in the rest of the universe might be like. Constant studying of the Sun will provide us with the necessary information to make the decision to stay or leave our planet in the future, and how life might be shaped by stars in the depths of the universe.

Clear skies!