They go over a bump or hit a pothole?
Hmm . . . Then a mere strip-mine of sufficient acreage . . . Heh-heh-heh . . . Ha-hah-hah . . . MMMMmmmmbwwwaaahhaahaHAHAHAAA!!! Thank you ever so much, Dallas. I have my Evil Plan now. 
So we should be very worried if Jack Bauer starts shooting at the ground, then ?
I’ve always hoped for a Superman story in which he discovers that Darkseid was responsible for Krypton’s destruction–or alternately, that the Guardians of the Universe were.
The former’ motives should be obvious; while Darkseid would see the potential for the Kryptonians as slave, he might ultimately decide that billions of humanoids, each of whom, as an adult, is mightier than his most powerful servants, was too much of a risk.
The latter requires a bit more elliptical thinking. It’s always bothered me that Kryptonians had such enormous power but ONLY when removed from their natural environment. There’s a Justice League story in which it’s asserted that the Guardians acted to restrict the potential power of the Martians (of a similar power class), so I can imagine them doing something to Krypton to prevent its inhabitants from reaching their natural potential; and I can also imagine that process, thousands of years later, causing the planet’s destruction. There’s ample precedent for the Oans being manipulative, arrogant, and incompetent, after all.
Everybody knows the Earth’s center is filled with dynamnite and it’s connected to a lever that pokes out of the ground so that if the lever is thrown, then KABLOOIE! And that lever is guarded by Nate the snake.
I had assumed that they went “ka-BOOM,” but an exhaustive (well I’m exhausted, anyway; maybe I should exercise more and start eating right) Google image search for variations of “Superman Krypton explosion” reveals that my theory was incorrect. Apparently in the DC Universe, at least, planets explode silently.
Who’d have thought comic books would top the list of scientifically accurate media?
Don’t you dare.
I’m getting worried that someone’s going to read this thread, realize that planets don’t shatter into little chunks… and retcon Kryptonite out of existence. Then we’ll have a douchy Superdude on our hands with no weakness.
So, Mr. Byrne (in case you’re reading)*, do NOT get rid of Kryptonite. We need it, and we can still have it if Jor-El’s a bad handyman.
Hey, the guy’s a scientist/politician, not an engineer. So when he tosses his kid in his protoype rocket and lights the fuse, I think the reader’ll understand if the rocket fizzles a little… then tumbles out the window with sparks shooting out of the back like a factory-second firecracker. After bouncing through Lara’s broccoli patch, it rights itself and the engine finally kicks in and “whoosh”/ “whew”, off it streaks.
With a couple of clods of dirt… Kryptonian dirt, mind you… stuck to the hull.
*or Waid or Bridwell or Shooter or David or Straczynski…
And is anyone here really surprised that there are some?
Personally, I favor the explanation that Krypton wasn’t actually a planet, but a cooled white dwarf. It’s been accreting matter from its red-giant companion, and Jor-El saw that it was approaching the Chandrasekhar limit. When it did, supernova.
You folks have it all wrong - you have to have an “Illudium Q-36 explosive space modulator” if you want an earth shattering ka-boom.
anything else simply won’t cut it.
I’m relly surprise that it took 32 posts for this. 
In her defense, every time she stops she buys a postcard and sends it in to the Federation Navy’s High Command.
It was actually Despair of the Endless who was responsible. She convinced Rao (Krypton’s sun) of the artistic value of destroying an entire planet so that there would be one survivor.
… Although, you would have thought she could have gotten his little dog, too.
Shortly after the original Star Wars came out, they discussed how much energy would be required to blow up a planet in American Journal of Physics. as The Bad Astronomer and others pointed out, it’s a heckuva lot of energy. Better to just smash an asteroid into it, or something.
It was Black Zero, in **Superman ** #205, in 1968. The story was written by the legendary Otto Binder, who should have known better. Maybe he was under the deadline, so he whipped out this continuity-destroying story. Neal Adams did the cover. Agent Black Zero discovers that Jor-el’s theotry about Krypton’s instability is incorrect, but he likes the idea, so he pushes along the dying down instability and helps Krypton explode.
Black Zero is bald, has a forkled tongue, and purple ryes (like Liz). He later showed up again in DC stories, but everyone agreed to forget about the Krypton thing:
Such as causing the very rocks of the planet themselves to release radiation that inhibits their powers. For instance.
I’ll see that and raise you, “Not with bang, but a whimper.”
As it happens, “space modulator” is as good a term as any for one of my handwaves for planet-ka-booming weapons (or random spatial phenomena): gravity inversion. It nullifies the largest single force holding the planet together while simultaneously inducing a force that tries to rip it apart. Of course, to the best of our knowledge, such a weapon/phenomenon is complete fantasy (as the Bad Astronomer might point out), but it provides sufficient deniable plausibility to satisfy me.
For bright, flashy ka-booms, instead of gravity inversion, you might postulate a (still more fantastic) antimatter converter weapon that changes substantial chunks of the planetary material into antimatter. Or swaps the planet’s core with its antimatter double in a symmetrical universe (bonus: ka-boom two planets for the price of one).
Sorta what I had in mind, except that it doesn’t explain the red-sun thing. Unless you’re suggesting a connection be made between that and kryptonite.