So what is going on with the sun lately? Perhaps you have been reading unsettling warnings on line about solar flares, Coronal Mass Ejections, unusual sightings of the northern lights and possible damage to our electrical grid. All of the above is true or at least possible. Here is what is happening in a nutshell.
Our sun is basically a gigantic thermonuclear explosion that produces and emits the equivalent energy of six trillion (that is a big number) Hiroshima-sized atomic bombs every second. Lucky for us we are almost 93 million miles away. It is rocketing through space at 500,000 miles per hour tugging the Earth and the other planets along with it. It has been doing all this for billions of years and will continue for billions of years to come.
Our sun is mostly stable and does not vary much in its output like some stars do. If it did, we would not be able to live here on our little planet. It does go through an 11-year cycle where it increases and decreases its output a little bit. We call it the sun spot cycle. Every 11 years the number of sun spots that can be seen on the surface of the sun increases and then declines. Sun spots are magnetic storms that break through to the surface of the sun. They appear as dark patches because they are a little bit cooler, about 4,000 degrees as opposed to about 6,000 degrees for the sun’s surface. The more sun spots we see, the more active the sun.
Humans have been closely observing sun spots since the 1700s. We are now in cycle 25, the 25th that has been observed. The last few cycles have been rather paltry and low energy. Many scientists thought the current one would follow that trend. However, the opposite appears to be happening. Our sleepy sun is waking up and flexing his muscles.
What happens when the sun wakes up, and should we be worried? The most dramatic of events happening now are Coronal Mass Ejections, which are literally giant explosions on the sun which can hurl billions of tons of charged particles out into space at speeds up to thousands of miles per second. Sound bad? It is. An astronaut on the moon might receive the equivalent radiation of 300,000 chest X-rays from one of these events. A CME, as they are called, happened a couple of weeks ago, but luckily it came from the far side of the sun and was not aimed at us.
Next time we may not be so lucky. Our dependence on the electric grid and instant communications make us vulnerable to these dramatic events. In a worst case scenario we could lose our communication satellites, cell phones, electricity, computers, and our ability to fly in air planes. That is just the beginning.
The Earth is not without her protections, though. We have a magnetic field that surrounds us and closer in, our atmosphere. The magnetic field, known as the magnetosphere, has prevented our atmosphere from being blown off into space for all the millennia we have been here. That brings us to the northern lights or Aurora Borealis as they are officially known. When we see their eerie dancing glow, we can rest easy knowing that we are being protected by the Earth’s magnetic field and upper atmosphere from the sun’s intense energy.
We still have two years or more to go for the sun’s energy to ramp up and get even more destructive. There is really not much you can do about it other than watch for the auroras and hope your cell phone does not blow up!
If you are out after dark, that really bright object in the west just after sunset is Venus. There used to be two up there. The other one was Jupiter, which is now riding off into the sunset glow and getting hard to see. When do you look for the northern lights? If you hear about a Coronal Mass Ejection coming our way, that would be a good time. Where do you look for them? In the north, of course!