If the super-bombs don't get you, the cigarettes will

Arthur C. Clarke brings the world to an end with an alarming frequency in his stories. I've been reading his book Of Time and Stars which has some seven world-ending, well, ends in about eighteen stories. Mostly he doesn't even bother explaining:

Overhead, without any fuss, the stars were going out. 

If you've read The Nine Billion Names of God, you'll understand why that line is well-nigh unforgettable. In comparison, the world-ending line in No Morning After is just lame:

"Listen, Bill," they continued. "Our scientists have just discovered that your sun is about to explode."

And then there's:

SUPER-BOMB TEST TODAY

What sort of bomb could destroy a world? A super-bomb, of course. What is a super-bomb? What does it do? Who gives a rat's arse anyway?

And this line doesn't end a world or even a minor planetoid, but I liked it anyway:

He could even afford the luxury of a cigarette. 

The smoker is wearing a space suit and is standing on a minor moon waiting for someone to pick him up!