From this episode I get to talk about something pretty neat: solar flares. Yes, the plot of this episode revolves around a magical forest covering the Earth over night in order to save it from a massive solar flare. Confused yet?
Solar flares are massive explosions on the surface of the Sun that release a significant amount of energy in multiple forms at once. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. So, one of the most important types is the release of electro-magnetic energy. So while it looks like a huge spike of fire is leaving the sun, by the time a solar flare reaches Earth the most important issue to watch for is the impact of the electro-magnetic energy. What is really cool though is that Earth actually has its own protection- an actual force field that dampens or repels the effects of solar flares.
It ends up looking something like this. Earth's atmosphere and magnetic field actually help protect from the impact of solar flares. These are called Van Allen belts- they are radiation belts that act as part of Earth's magnetic field- and when the stream of high energy particles meet Earth's magnetic field they are push along these belts towards the north and south poles. Sometimes these flares can cause geomagnetic storms though which have the potential to cause some issues on Earth. For example, in Quebec, Canada in 1989, a rather large solar flare interrupted the power grid, exploding transformers and causing major black outs. There is also the fact that these solar flares can cause damage to satellites in orbit around Earth: they can be hit by high energy particles or damaged by a high currents caused by geomagnetic storms.
Even so, from Earth these solar flares actual look pretty cool.
So now the question is, did Doctor Who get it right? The answer is unfortunately not. What is a magical forest of trees going to do against electro-magnetic energy? This is what the show did:
By the time a solar flare reaches Earth, it just isn't a fire ball anymore and so this not what would actually happen.
Ok so that's all! I've actual learned quite a bit about solar flares in order to write so that's really cool! Thanks for reading!