Chapter 3

CHAPTER 3

WHAT HAPPENS WHEN STARS DIE? WITH PROFESSOR CRUELLA CRACKLESNAP

WELCOME TO YOUR THIRD CLASS, MALEVOLENT MONSTERS. STARS ARE A BIT LIKE PEOPLE. Not exactly like people, of course. People don't generally weigh a BILLION BILLION BILLION TONS and have nuclear reactions inside them. (If you do, please go and see the Academy nurse.) What stars have in common with people is that they are born, they live their lives, and eventually they die. When stars die, it can be very DRAMATIC. They swell up to millions of times their original size then violently explode.

I don't know about you, but I'm quite glad that stars and people don't have this in common. In the last lesson, we went back in time and saw how the Sun formed. Today, we're going to go forward in time to see what happens when the Sun dies. TIME: 5,000,000,000 YEARS IN THE FUTURE. ABOUT 8AM.

Our Sun has been happily burning HYDROGEN since it was born nearly 10 BILLION YEARS AGO. The nuclear reaction that powers the Sun uses up hydrogen (the stuff the Sun is made of), makes energy, and leaves behind HELIUM. When the SUN was first born, it was mostly pure hydrogen. But burning away for billions and billions of years makes a lot of waste, and slowly, the middle of the Sun fills up with helium. If you're a helium atom, this sounds like great news—YOU'RE HAVING A GIANT PARTY WITH ALL YOUR HELIUM FRIENDS.

BUT if you happen to be living on a planet orbiting the Sun (and, if you're reading this, you are), this is BAD NEWS. Because once the Sun's core is totally filled with helium, the Sun is going to DIE. LET ME ASK YOU A QUESTION: WHAT'S YOUR FAVORITE TYPE OF HAMSTER? Actually, that's a very stupid question. We're supposed to be talking about the Sun. LET ME ASK YOU A BETTER QUESTION: WHY DOESN'T THE SUN GET SMOOSHED INTO A TINY BALL BY ITS GRAVITY? The Sun is about 300,000 times heavier than Earth, so its gravity is REALLY STRONG.