And right now there's a whole group of geeky European space scientist guys and girls pointing in the direction of Houston, singing "Who are ya?".
If they're not, they should be. An utterly remarkable achievement.
Yes - ish. Of course they'd have to launch the missile 11 years in advance of it hitting us, and there's a 5 year build programme prior to that. But it's ok - current technology allows us up to a full 6 months of warning of an object likely to hit us, so that should be ok. Oh.