An 8 MT impact on the Moon is what the Moon calls "Tuesday." It has dealt with far, far worse.
The impact probably wouldn't even be visible with the naked eye unless it hits a part of the Moon not then illuminated by the Sun -- in which case one might see a brief flash of light.
Because I was curious and had no idea about the relative size of meteors that hit the moon, the one that hit the moon in 2013 and was captured by Spanish astronomers was traveling at 65k KPH and weighed about 400kg. That had an impact energy of 15 tons of TNT (https://www.youtube.com/watch?v=perqv4qByaI&t=1s)
Safe to say, an 8 megaton impact from one that weighs 220,000,000kg would be a bit more substantial! Apparently that would be roughly the size of the Meteor Crater in Arizona (https://en.wikipedia.org/wiki/Meteor_Crater).
The impact probably wouldn't even be visible with the naked eye unless it hits a part of the Moon not then illuminated by the Sun -- in which case one might see a brief flash of light.