The odd Fact Book

How did we get here?

. Make the most of planet Earth

Most of us take the Sun for granted. If we pay attention at all, it's either grumbling that it's come up as we pull the blanket over our head in the morning, moaning there's not enough of it in the Summer, or doing that very British thing of announcing after one day of sunshine that Its 'too hot, I mean I like it hot, but this is too hot.' Without it, not only would there be no life on earth, there would be no anything. It's kind of ironic that the basis of every single thing we know of on Earth is made up of stars that died a long time ago, yet (assuming us humans don't blow the planet up in the next billion years, which is a very big assumption,) It's our closest star that will ultimately destroy it all. The Sun, as I'm sure you are all ready aware, is a burning ball of hydrogen and helium gas. ( With small amounts of other bits and bobs.) It's far to say It's quite big, and it's held together by the same gravity that allows the planets in the solar system to orbit around it. We love the Sun because without it, Earth would be cold, barren, dead and it would be very hard to get a tan. But it's all ready tolerated us for four fifths of the time It's willing to and, in about a billion years or so, It'll throw it's toys out of the pram in a cataclysmic grump. A billion years, you say? That's ages. A billion years ago we were all just sludge and now we have aeroplanes, iPads and emojis. In another billion years, think what we could do. Well, yes, you're right to an extent but it will happen. It's non-negotiable. Now I don't know about you, but I can still remember lying awake at night trying to accept the fact that I would die eventually. When I think about the Sun dying, I get the same cold feeling. (See what I did there? haha)

So how will this happen Savannah?

The Sun emits more energy in one second than has been used in the entirety of mankind's history via a process called fusion, which transforms hydrogen into helium and a little light and heat. Once our star has exhausted the hydrogen in its core, fusion stops and outward pressure of the reaction means the Sun is no longer strong enough to resist the force of gravity, so It caves in on itself. The entire mass of the star is squeezed into an increasingly small spot where the heat and pressure become so great that all of the helium created by the initial reaction actually transforms into carbon. The energy from this is so great that it sticks two fingers up to gravity and starts to swell. Our adorable little home planet is situated smack bang in the middle of what is known as the habitable zone.  We're not so far from the Sun that we freeze and not to close that everything we know and love, combust to ash. However, when the Sun expands, the habitable zone in our solar system won't be so habitable anymore. It's estimated that the Sun will exist for another 5 billion years or so after that, but it won't go quietly and we're all screwed well before it finally kicks the celestial bucket. As it expands it will become a red giant, and swallow Mercury and Venus and most likely Earth to. The good news is that there is a possibility that it won't grow large enough to actually engulf us. The bad news is that it makes absolutely no difference either way because we'll be much to close to it and therefore much to dead long before it touched us. The best estimates give a life expectancy for Earth of somewhere around the billion year mark. Bearing in mind that this planet was only created about 4.5 billion years ago, It's less than you might have hoped for, still, a billion years should probably be plenty of time to find another star with another suitable planet in another habitable zone for us to get cozy on. (That was 100% sarcasm.)