The internet, and the news, have been ablaze for the past week or so about the sudden rise in solar activity. The Sun has unleashed a relentless barrage on our planet's magnetic field, and the rest of the Solar System for that matter, with one solar flare after another. These haven't been minor incidents either. Our closest star has really been flexing its muscles with eruptions that have fallen among the strongest classes given to measure solar emissions. You've undoubtedly read or heard a lot of science technobabble regarding this rash of increased solar activity, so I thought we'd break it down and shed a little clarity on the subject.
The Sun, like our planet, is made up of distinct layers. In simple terms, it is an enormous collection and network of intensely hot plasma and magnetic fields. These fields are constantly moving and evolving. The Sun itself is essentially a giant nuclear reactor, constantly conducting the process of fusion, where Hydrogen is converted into Helium. At the Sun's core, where this process takes place, the temperature reaches an unfathomable 15.7 million degrees Kelvin. By contrast, the Sun's "surface" (the part we visibly see), is a balmy 5,800 K or about 9,980°F. I won't get into too much of the real heady details, but if you'd like some great info on the Sun and other Sun-related info, check out the following link.
http://en.wikipedia.org/wiki/Sun
On to the subject of solar flares. Have you ever held two small magnets in your hand and tried to force the "similar" sides together? That is, have you ever tried to force two magnets together facing the wrong way and felt them push back against each other? The rule with magnets of course is "opposites attract." So, what happens when you let go of those magnets you try to force together? Often, they'll flip and connect. That same process occurs constantly on a phenomenally larger scale on the Sun. When the shifting magnetic fields manage to connect, an immense amount of energy is released from the Sun's surface in the form of energized particles and even plasma from the Sun's interior. Like a volcano, the more energy that builds up prior to the magnetic fields connecting, the larger the eruption, and the ensuing solar flare.
Above is an ultraviolet image of the Sun. The bright spot in the upper-left is an X5-class solar flare that erupted on March 7, 2012 at 7:38 ET.
Solar flares are ranked into one of three classes according to how brightly they appear when viewed through an X-ray image. The actual breakdown is extremely heady, so I'll stick to the bare bones. From weakest to strongest, flares fall into C, M, and X classes. Then, within each class, a number is given ranging (generally) between 1 and 9. The previous photo shows a solar flare that ranks among the strongest than can possibly be recorded.
So, what does all of that babble mean for us here on Earth? Well, one last little science lesson, I promise. Our planet, and the other 7 in our Solar System, are constantly being barraged by energized particles that radiate from the Sun in what is called the Solar Wind. These particles, mostly protons and electrons, race through space and smash into our planet's magnetic field. That field protects us from bearing the full brunt of this radiation, and even helps keep our atmosphere from being blown clean off. However, a more pleasant side-effect is that we get those constant colorful displays around the North and South Pole known as auroras or the Northern (or Southern) Lights! In simple terms, this happens because the charged particles begin to glow when exposed to magnetic fields, and due to the orientation of our magnetic field, they collect around the Poles.
Displays such as this, seen over Iceland, can be pushed farther south due to solar flare eruptions. Since we already have a steady flow of particles striking our magnetic field, solar flares can be thought of as huge gusts of solar wind. With a higher amount of particles, smacking into the magnetic field, events known as geomagnetic storms can develop and cause Northern Lights displays to be seen in areas farther south than normal. In fact, with the recent X5 flare, auroras were reported as far south as Kansas, Illinois, and Wyoming just to name a few states.
While solar flares and solar storms can give us some beautiful sights in the skies, the more powerful ones can have detrimental effects here on the ground. The most common effects are more of the nuisance-variety. Radio signals can be disrupted or blocked entirely for the duration of the flare's impact on Earth. This may even spread to cellular activity, causing disruption of cell service or even blackouts. More pronounced and potentially hazardous effects include interference of GPS signals, entire power grids can be knocked offline, and in the most extreme and rare cases, it can even interfere with medical devices such as pacemakers. Often times, during an especially strong solar storm, air traffic is re-routed to avoid courses near the Poles. Since the bulk of solar particles and radiation collect in the atmosphere near Earth's Poles, airplane passengers could be exposed to small doses of radiation if a plane we to fly through these areas during the height of a solar storm. I want to emphasize however, that these impacts I mentioned are well-documented and planned for, so there is no reason to worry when you hear reports of an incoming solar flare. On average, it takes radiation from solar flares about 2 days to reach Earth, so we see them coming long before they get here.
Wow, that was a lot! And the scary part is that we barely scratched the surface on this subject. I hope, though, that I was able to shed some light on the subject. The threat for large solar flares is diminishing for now, but we'll see what happens in the coming weeks and months! I'll leave you with some neat pictures from this latest burst of solar activity. Enjoy!
Northern Lights spotted over Alaska around the time of the X5 flare impact.
A thin aurora spotted over Murmansk, Russia on a cloudless night.
Believe it or not, this is the Sun! A photographer in New Mexico was able to capture this with a standard camera. The dark spot on the upper-right side is the sunspot that caused the rash of X-flare during early March 2012. This could be seen with the naked eye!
Until next time!
Great write-up Bryan
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