Hank Green: Hello, this is Hank Green with your daily space weather forecast. And here we have the Sun (over here) doing its sun thing, sending out gentle, harmless sprays of electromagnetism onto Mercury, Venus, and eventually Earth.

My forecast calls for more of the same. Moderate activity, lovely -- what? Holy! What is--? Oh my! What's it doing? What are you doing? Holy Moaning Myrtle! Jesus! [Runs off screen]

[SciShow intro]

I don’t know about you, but THAT -- that enormous, unstoppable torrent charging at the Earth like a tsunami of radioactivity -- makes me want to go hide under my bed.

This footage was captured by the un-interestingly named STEREO-A, one of two spacecraft launched in 2006 to help NASA study solar activity. These eruptions that you're seeing here happened in December 2008, so I suppose we're safe since it happened a long time ago. And it’s the first time that we’ve actually seen what it looks like when a solar storm engulfs our planet.

A single, normal one of these eruptions can send a billion tons of ionized gas, a billion tons of solar plasma, hurtling toward our planet.

And the thing of it is that, in terms of space weather, this, that happened on December 28th, is not that big of a deal, practically San Diego.

When things get really intense, it's at a period called solar max, which happens on an eleven-year cycle. And, frankly, That's when the really crazy crap happens.

As you might expect, the sun has some pretty strong magnetic fields and, just like the Earth, it has north and south poles. But because the sun not, in fact, a mass of incandescent gas (it is an enormous ball of juicy plasma), its magnetic fields are always churning around and stretching and contorting. And by the time they’re done shifting, every 11 years or so, the poles have reversed. South becomes north and vice versa.

And while this is happening, the magnetic fields cross and sort of poke out from the middle of the sun, and they go all crazy basically, and cause all sorts of crazy, dangerous-looking phenomena. Very much like what we just saw, which is called a coronal mass ejection -- this is when the sun’s corona emits these huge plumes of ionized gas. And when I say huge I mean that the disc in the middle of this picture is the sun, that's the sun! And those giant popping bubbles are pretty much as big as the sun itself.

And, sometimes, magnetic fields that had been going in opposite directions connect, effectively short circuiting themselves. This causes solar flares, which are localized blasts of radiation. Even short ones lasting just a couple of hours can unleash enough energy to power the entire United States for a million years.

And where these magnetic fields actually emerge from the surface of the sun, then we get what's called sunspots. These spots become more frequent and eventually peak at solar max, telling us that things are about to get real.

Now, because of their enormous energy, these storms can actually affect things that use electromagnetism here on the surface of the Earth, which, today, is practically everything. Transformers on power grids get thrown off line. Radio and satellite communications go on the fritz. During one of the biggest flares ever recorded, in 1859, telegraph machines picked up so much energy that the ones that had been turned off started working. And that's lovely, because it is the exact opposite of the effect that it would have on cell phones, which now just stop working during solar flares.

And of course, these radiation plumes pose health risks to astronauts -- people who are living outside of the Earth's electromagnetic field. But, at least they will get a lovely view of these auroras from space.

Unfortunately these storms remain massively difficult to predict. Which I guess isn't that surprising, given that the sun is a pretty complicated system. For example, in 2006, scientists said that 2010 would be a huge solar flare year, almost beating out 1958, when it was said that the northern lights could be seen as far south as Mexico. And of course, 2010 turned out to be something of a nothing year for solar flares.

So, as much as I like being your space weatherman, I'm not gonna quit my day job.

Thank you for watching this episode of SciShow. If you want to know more about solar flares and the peculiarities of the Sun, there's, of course, citations in the description below. If you want to asks us questions or suggest topics for future episodes, please connect with us on Facebook or Twitter, or, of course, the YouTube comments below. Goodbye.