My friend Cara Santa Maria is a scientific researcher and educator. She’s also Senior Science Editor with The Huffington Post, where she does a video show called "Talk Nerdy To Me". She contacted me recently because she wanted to do an episode on solar storms – how they work, and how they can affect us here on Earth. She interviewed me about them, and the episode is online at HuffPo:
[Note: If the video doesn't appear directly above this sentence, refresh your screen.]
The Sun has been a bit feisty lately, spitting out some decent flares and coronal mass ejections. So far, none has been both strong enough and aimed at us to do any damage (there was a fairly powerful CME in July, but it was on the other side of the Sun, directed away from us). And while they can’t hurt us directly due to our protective atmosphere, as I say in the video solar storms can disrupt our power grid and our satellites, creating havoc. The more we study the Sun the better we understand it, and the more likely we’ll be able to protect ourselves should it decide to throw another major hissy fit.
I’ll add that Cara’s good people, and I like her show (she interviewed me for the Venus Transit, too). She’s passionate about science education, and like me she finds real joy and wonder in all fields of science and nature. You can follow her on Twitter.
[Edited to add: the shirt I'm wearing in the video (watch to the very end!) is available at Lardfork's Spreadshirt store.]
Active sunspots are pretty dramatic all by themselves, but a little over-the-top music can’t hurt.
This spot has been spitting out some low-level activity, but the Sun is tricksy. We’ll see if we get some bigger ones as this thing rotates in our direction over the next few days. Be on alert for aurorae!
Is the solar cycle shutting down?
New results indicate it may very well be, at least temporarily. Even though the Sun is currently approaching the peak of its cycle in 2013, and we’re seeing an increase in activity (more sunspots, flares, and other violent events), there are strong signs that the next expected peak (in 2022 or later) may be weaker, or may not come at all!
Here’s the deal. The Sun is a seething ball of ionized gas, called plasma, and has very complex magnetic fields that interact with this plasma. The overall strength and activity from the magnetic field rises and falls on roughly an 11 year cycle. When the cycle is at its minimum the field strength is weak, and we see few or no sunspots or other activity. Then, a little over five years later, the cycle peaks and there’s lots of fun stuff going on, with flares, coronal mass ejections, and more.
Scientists studying the Sun have been trying to figure out this cycle for over a century. It’s very complex, but as technology has gotten better, some trends have been found. And recently, these indicators are all pointing to the Sun settling down magnetically.
For one, there is an east/west river of gas the flows under the surface of the Sun (it can’t be seen directly, but it generates sound waves that travel from it to the surface, revealing its presence; I describe this in detail in an earlier post). This river comes and goes, but usually forms at mid-latitudes on the Sun and shifts toward the equator as the cycle progresses. As it does so, sunspots form above it. Although the next cycle won’t start for a few years, the river associated with it should already be forming. However, there are no indications it has, making astronomers think the next cycle may be delayed.
For another, scientists have found that the average magnetic strength of sunspots has been declining over the years. Sunspots form when magnetic fields inside the Sun break through the surface. Normally, rising gas from the solar interior would cool and drop back down, but due to the way the magnetic fields interact with the gas, the cool gas is prevented from dropping. Cooler gas is dimmer, so we see this as dark spots on the Sun: sunspots.
Sunspots are an intrinsically magnetic phenomenon, so this trend of weaker magnetic fields inside them may be indicating, again, the next cycle may be delayed or not come at all.
Moving farther outward yet we come to the third line of evidence of a weak upcoming cycle. The Sun has an atmosphere, called the corona, of very thin but extremely hot plasma. It too is greatly affected by magnetic fields; every cycle the magnetic activity in the corona tends to form near the Sun’s equator and then slowly move toward the poles over the next few years. This "rush to the poles", as the scientists call it, is very weak this year, and may indicate that the peak in 2013 may not be terribly active. It’s unclear what this might mean for the cycle peak after that.
So what does this mean for us? Read More