Bob and Joe are two ordinary citizens in the City of Coventry who like drinking tea, eating biscuits and what their wives would call: ‘Having a moan’.
On one balmy evening, the two of them are out in Bob’s backyard.
‘Ey up, Bob. have a look out ’ere tonight. I can see stars. ’ Joe had his head tilted skywards and he was waving his arm around.
‘Did ya bang yer head?’ Bob stared at his friend like he was a man having a moment. And his face picked an expression that was one of confusion.
‘No, you numpty. I mean the stars in the sky.’ Joe chuckled.
‘Look at that one there. Nice and bright that one is, Joe.’ Bob was clearly getting into the stargazing thing.
‘That’s Betelgeuse, that is.’ Joe spoke like a man who knew what he was talking about. Whether that was true or not, is uncertain.
What they don’t know is that Betelgeuse is 640 light-years from Earth. So, the light Joe and Bob are seeing left the star in about 1386. 640 light-years is 3.76 quadrillion miles—which is roughly the distance a commuter train on the West Midlands line feels like it’s travelled when it’s delayed by leaves on the track.
‘Looks a bit orange to me, Joe. Why’s it orange?’
‘Nah, it’s your glasses reflecting the street lights.’
Bob stared at the bright spot a bit harder. Trying to make his eyes see what Joe was seeing. But his eyes didn’t like that, because they couldn’t know what Joe’s were seeing.
‘D’yer know ’ow far away it is, Bob?’
‘No clue. But I’d say a bloody long way. Dunno how it’s possible we can see it.’
Something else they don’t know. Betelgeuse is colossal. If it were placed at the centre of our solar system, its outer layers would stretch past the orbit of Jupiter, swallowing Mercury, Venus, Earth, and Mars.
‘I ’ope the bugger doesn’t decide to go bang, Joe.’
‘Ah, I read about it. At roughly 10 million years old, it’s nearing the end of its stellar life. It’s used its hydrogen and is now fusing heavier elements, meaning it will eventually explode as a supernova.’
‘Will it? Bloody hell. When? And you sound like a science book.’ Bob was scratching the back of his head. But the back of his head was confused as well.
‘Dunno, mate. I’d say you’ve got time to make another brew.’
The fellas needn’t worry. While Betelgeuse is a prime candidate for the next galactic supernova, it is not in imminent danger of exploding within our lifetime. Estimates suggest the detonation could happen anywhere from “tens of years” to 100,000 years in the future. When it does finally go supernova, the explosion will pose no threat to Earth (as we are well outside its kill zone) and will shine so brightly it could be visible to the naked eye in broad daylight.
‘Right, I will. Are you staying out here doing yer Patrick Moore or what?’
‘I’ll come in, I fancy a biscuit with that tea.’
Which was sensible. Because while Betelgeuse has survived 10 million years of nuclear fusion, the chocolate digestives in Bob’s kitchen rarely last past 9:30 PM.