I like the Pre-Crisis fat of Krypton a lot more than the current version. Post-Crisis (according to the initial Byrne retcon, anyway) it seems like Jor-El just comes back from an expedition one day and says 'wifey, the planet's gonna go kaboom any second now. Not to worry, though - I've taken the liberty of sticking our son on a rocket ship, so he'll be fine. Whoops, looks like it's happening now; there he goes, oh, by the way, did I ever mention that I love y...' BOOM! Pre-Crisis, however - well, that first page does a pretty good job of summing it up. Jor-El SQUIRMS. He knows that the planet is going to blow up, but he can't stop it, and his warnings come to naught. I'm not surprised that he tosses and turns in his bed, and sweats a lot and drinks too much coffee. Imagine - just imagine - what such knowledge would be like. A whole world - history, culture, artworks, monuments, follies, triumphs - all of it gone. Not simply your own life's work, everyone's. Everyone, everything, every living creature on the face of the planet wiped out in a matter of minutes. This expresses that pretty well.