>>716280692
One of the Most recent examples of a at-risk meteor was 2024 YR4, which was calc'd to have a risk of hitting us in 2032. Most Objects, aside from Extra-Solar Objects like Oumuamua, can be predicted years in advance.
And We've already successfully tested the use of Spacecraft to deflect objects, with DART deflecting Dimorphos
We'd be fine, so long as the window of discovery wasn't ridiculously short.