Would Jupiter ignite if we could somehow detonate a 50 megaton warhead at its core?

Jupiters core is iron, so NO.

You're right, the Shoemaker Levy impacts didn't cause the heat and pressure of a nuclear detojnation. They *exceeded* it by several orders of magnitude! The scars left by the comet impacts were wider than the entire planet Earth, and were clearly visible in telescopes even from here, nearly half a billion miles away!

Nuclear explosions may be the most powerful and destructive thing we've ever made here on Earth, but they really do pale in comparison to the energies released by high speed impacts of objects massing several tons. Stories of nuclear blasts pushing the Moon out of orbit or cracking open the planet are pure fantasy. They simply do not release enough energy to have that effect on a planet-sized object. Take a look at aerial photos of the Nevada test site. It's full of holes made by nuclear explosions, but they're all quite small when compared to, say, craters on the Moon that you can see in binoculars from 250,000 miles away. If an explosion powerful enough to rip out, say, the South Pole-Aitken basin on the Moon did not tear it apart, what's a nuclear bomb, many orders of magnitude less powerful than that, going to do to a planet the size of Jupiter? Not a heck of a lot, really.

'Ah, but Jupiter is made of hydrogen, a flammable gas', I hear you say. Well, true, but without oxygen hydrogen cannot ignite. Jupiter has no means to support combustion of its hydrogen. How about nuclear fusion, as powers the Sun, also using hydrogen as fuel? If Jupiter was capable of sustaining nuclear fusion it would already be doing so. The pressure and temperature at the core is just not high enough to get nuclear fusion started. Detonating a bomb in there wouldn't help either. Even if you could make a bomb that could reach the core without getting crushed by the immense pressure, that same immense pressure would contain the explosion. The comparatively tiny addition of heat and pressure from the bomb would be insignificant compared to the pressure of trillions upon trillions of tons of matter pressing down on it.

So, Jupiter is massive, nuclear bombs are tiny in comparison. Nothing we humans could do to any planet compares to the forces involved in the natural collisions they have all withstood for billions of years.

Would not work, at best, you can expect a short fizzle. Jupiters gravity is not strong enough to sustain a nuclear fusion reaction inside it's core. Jupiter would need in the most optimistic calculations about ten times more mass, for just becoming a Brown Dwarf star (which could sustain nuclear fusion for a short time). Jupiter would need 75 times more mass for starting fusion itself. Not just 10%.

50 MT would be a microscopic explosion compared to Jupiter.

Also, you are wrong about the comet impacts. While not the same as a nuclear explosion, they unleashed actually much more energy in each impact as the strongest nuclear explosion we had on Earth (with 50 MT a good example). The largest fragment which impacted on Jupiter, fragment G, released 6 Teratons TNT of energy or 6,000,000 MegaTons. And that energy got unleashed in the same short instant as a nuclear explosion, causing much higher pressures and temperatures as the Tsar Bomb explosion.

No.

I'm afraid you earthlings are a bit too impressed by your technology. First, the size of the earth is absolutely tiny compared to the mass of jupiter. It would be like comparing a ping pong ball to a basketball. The "50 megaton blast" you mention would be somewhat like the amount of energy generated by a falling particle of dust. The comet which Jupiter tore apart generated the same amount of energy as the asteroid which killed off all the dinosaurs. This was more energy than could be generated by all the nuclear bombs on earth. All this did was create a couple smudges in jupiter's cloud layer. I really think you earth people ought to abandon science fiction and embrace science fact instead. If you did, you would understand jupiter can't be "ignited" since there is no Oxygen in its atmosphere. Secondly, to achieve fusion, matter must be compressed, not expanded. When things blow up, they expand. The big picture is - what is your species obsession with detonating and igniting things? Fire was a noble achievement, but try not to use it on one another.

Live long and phosphor,

Anus from Uranus

maximum possibly there could be no observable distinction in the planet as seen from the earth. 50 megatons isn't lots diverse than a firecracker whilst weighed against the mass of Jupiter...there is basically approximately no risk of the planet mutating magically right into a dwarf celebrity, by using fact it quite is not a celebrity now.....

I remember one of my professors telling me that Jupiter would become a star if it had 10% more mass. So I don't think the trigger mechanism alone would do it.

P.S. Perhaps I am remembering it wrong. It may indeed have been "ten times the mass".

It would cause a tiny blip that would have virtually zero affect on the planet.

Just keep dumping flaming liberals into Jupiter. Sooner or later it'll have to do something.

why would anyone want to destroy an innocent planet?