Make a probe with a giant fuel tank and engine land on the asteroid then just fire away to push it slightly off target so it misses the planet. Don't need to destroy just alter the trajectory a tiny bit.

Wtf, no, the way to deflect an asteroid is to send something near it while it's far away. Blowing it up just risks another smaller asteroid hitting us. Small changes in direction while incredibly fast away will change its path enough to be safe.

Don't even need a warhead. The Double Asteroid Redirect Test (DART) just threw the probe itself at an asteroid hard enough to affect its orbit.

Unmanned? Nah, lets just assemble a team of oil drillers and send them up there like space cowboys.

Well it would still have an impact energy less than that of tsar bomba, and probably just hit an ocean.

What are you talking about Shelbyville, why would we want to marry our cousins?

I can't blame them, their cousins are hot.

yeah, yeah it is

Yeah, because at best it just splashes in the ocean, worst it hits a city and causes mass suffering as thousands die from the impact and fallout. It's not going to end any suffering

Yes, because it's not going to be nearly as catastrophic as it sounds. What we need is a real world ender.