5. How long does an Earth-size planet take to form from a 1km diameter rock?

Firstly, a 1km asteroid isn’t an “Earth Killer”.

Secondly, with only one week - we’d stand zero chance of deflecting it - and it’s well understood that attempting to destroy it would make matters worse - not better.

So it’s going to hit us for sure…not a darned thing we can do about it.

How much damage would it do?

The asteroid that killed the Dinosaurs was 15 to 20 times that diameter - which means it was between 3,000 and 8,000 times heavier - and therefore delivered thousands of times more destructive force than your rather puny 1km rock.

A rock that big could easily kill most humans and other large life-forms, but life continued after the dinosaurs and we’d be at least somewhat better prepared…so even a VASTLY larger rock than yours wouldn’t destroy everything.

A 1 km asteroid would be about 100 times more devastating than the Tanguska event - which would be a considerable impact - but definitely something survivable to the majority of people in the world.

Tunguska is estimated to have produced an explosion equivalent to about 10 to 20 megatons of TNT. So your asteroid would probably produce 1000 to 2000 megatons!

That’s a heck of a lot.

the answer is b. glad to .

the answer to your question is tooth decay.