Have you been lucky enough to spot the Northern Lights this summer? Those curtain-shaped patterns of light are one of the most beautiful sights in the night sky, and officially they are known as the Aurora Borealis.
Why did they suddenly become a happening thing this year? To answer that question we have to take a closer look at our own personal star, the sun. Imagine a seething, hot electrically charged ball of gas 865,000 miles in diameter. That is our sun, and it emits the equivalent energy of 6 trillion Hiroshima-sized atomic bombs every second. In case you forgot, a trillion is a big number. That hot gas is on the move inside the sun, and sometimes a charged magnetic storm will break through to the surface, producing a sunspot.
Sunspots have been counted on a daily basis ever since the year 1755. That sounds like a long time, but remember our sun is about 5 billion years old. We have learned that they come and go in cycles about every 11 years. The more sunspots, the more energy our sun is putting out. Guess what? Right now our star is ramping up the number of sunspots that can be seen on its surface.
What does all this have to do with the Northern Lights? We are constantly being bombarded by something called the solar wind, charged particles being blasted out of the sun in our direction. Right now that wind is turning into a hurricane. Big blobs of matter from the sun called coronal mass ejections can be shot outward in our direction at the speed of thousands of miles per second.
These ejections can cause a lot of damage to our electronic infrastructure like satellites, cell phones and the power grid. It has been estimated that a direct hit on the earth could cost trillions of dollars in damage and take up to a decade to fix.
But we are not defenseless. The Earth has its own built-in protection, a magnetic field surrounding us. That is what we see when we are looking at the Northern Lights: our magnetic field protecting us from incoming charged particles from the sun.
The current sunspot cycle is turning out to be stronger than predicted, and we have not hit the maximum yet. That will not happen until sometime in the year 2025. So the best is yet to come in terms of viewing the beautiful Northern Lights. If all our cell phones get fried, however, then we will not be too happy.
How do you know when to look for them? Those outbursts that produce the most-stunning displays are traveling at high rates of speed and can cover the distance between the sun and us in just hours. Google Geophysical Institute for predictions of when to view the Northern Lights.
As to where to look, maybe you guessed it already: the north. Now that the nights are getting longer, there will be more of an opportunity to see them since the sun’s glare makes them impossible to spot during the day.
Not the sun’s fault
Can the increased intensity of the sun heat up the Earth, making climate change worse? Climate deniers often point to the sun, blaming it for our troubles. Climate scientists have estimated that a hotter-than-normal sun could raise our temperature slightly but only by about a tenth of a degree, far less than our carbon emissions. We have only ourselves to blame for the scorching temperatures we have endured lately.
If you are out looking for the Northern Lights, check out Jupiter and Saturn, which are easy to spot. Saturn is dimmer and higher up in the south, while Jupiter is brighter and lower in the east. Jupiter is closer to us than it has been in the last 50 years or so. Both of these planets are great to look at through a small telescope, so dig out that scope buried in your attic somewhere and have a look.
One last question. Are there Southern Lights? You bet there are, and they are called the Aurora Australis.