no end to mankind.

With the current population at approximately 6 billon people.
I think that if an asteroid hit the earth killing 80% of the people. There would still be enough people to repopulate the earth again.
Are best bet is to safeguard are technologies and philosophies
from being lost and forgotten.

Just what technologies and philosophies do you think are so crucial to saving mankind from oblivion? For that matter, what makes you think mankind is even worth saving from extinction? I firmly believe that given vast resources, advanced technology, and a desire to reach for the stars, this race is still doomed to die on this miserable little rock. If an asteroid hits and snuffs 80%, the remaining fifth will probably come up with an effective alternate method of self-destruction.

Better off for Earth, and prolly better for the universe if we were to up and die.

What have we contributed to this reality that is necessary to its continuance? How have we improved things just for the sake of doing something good, not to better our own lives?

Now that I’ve said that, I don’t think that a meteor that could destroy 80% of the population while not striking any highly populated areas (China, India, Kansas, etc.) the survivors wouldn’t be looking at a very bright future. Sure, we could probably find a means of generating power. We might have a hard time with all the volcanoes and such, but maybe we could plant a garden. And, as always, there’d be plenty of cockroaches to eat.